TW202241035A - Power converter and motor module - Google Patents

Abstract

This power converter converts DC power into AC power of n phases. The power converter comprises: n-number of output terminals; a first power supply terminal; a second power supply terminal; and n-number of serial bodies. During one period of AC outputs of the n phases, at least one phase of the AC outputs has a protective operation mode having at least one of a first on-fixed period during which a first semiconductor switching element is set to ON in a fixed manner and a second on-fixed period during which a second semiconductor switching element set to ON in a fixed manner. In the protective operation mode, in at least one of the n phases, the first on-fixed period is different from that of one of the other phases, or the second on-fixed period is different from that of one of the other phases.

Description

Power Converter and Motor Module

The invention relates to a power converter and a motor module.

A motor control device that drives a three-phase motor is known (for example, Patent Document 1). In the motor control device described in Patent Document 1, the temperature rise of the switching element is suppressed by fixing each phase voltage of the three-phase voltage to 2π/3 or π/3.

prior art literature Patent Document 1: Japanese Patent Laid-Open No. 2005-229714.

The technical problem to be solved by the invention However, in the motor control device described in Patent Document 1, only the temperature rise of the switching elements on the high side can be suppressed uniformly, the temperature rise of the switching elements on the low side can be suppressed uniformly, or the temperature rise of all the switching elements can be suppressed uniformly. The temperature rises. Therefore, a specific semiconductor switching element of a specific phase cannot be protected. The present invention was made in view of the above-mentioned technical problems, and an object thereof is to provide a power converter and a motor module capable of suppressing the heat generation of a first semiconductor switching element of a certain phase and a second semiconductor switching element of a certain phase at the same time, thereby suppressing power consumption. heats up the converter and improves reliability.

Technical solutions adopted to solve technical problems An exemplary power converter of the present invention converts direct current to n-phase alternating current. The power converter includes n output terminals, a first power supply terminal, a second power supply terminal and n series bodies. The n output terminals output n-phase output voltages and n-phase output currents. A first voltage is applied to the first power supply terminal. A second voltage lower than the first voltage is applied to the second power supply terminal. The n series bodies are connected in series with two semiconductor switching elements. n is the number of phases of the AC output, which is an odd number of 3 or more. The n serial bodies are connected in parallel with each other. One end of each of the n series bodies is connected to the first power supply terminal. The other end of each of the n serial bodies is connected to the second power supply terminal. The n series bodies each have a first semiconductor switching element and a second semiconductor switching element. The first semiconductor switching element is connected to the first power supply terminal. The second semiconductor switching element is connected to the second power supply terminal. The first semiconductor switching element and the second semiconductor switching element are connected at a connection point. The respective connection points of the n serial bodies are connected to the n output terminals. The first semiconductor switching element is switched between on and off at a frequency higher than that of the AC output. The second semiconductor switching element is switched between on and off at a frequency higher than that of the AC output. During one period of the AC output of n phases, at least one phase of the AC output has a protection operation mode, and the protection operation mode has at least one of a first fixed period of on and a second fixed period of on, During the first fixed on period, the first semiconductor switching element is kept on, and during the second fixed period of on, the second semiconductor switching element is kept on. In the protection action mode, in at least one of the n phases, the first on-fixed period is different from the first on-fixed period of any other phase, or the second on-fixed period The period is different from the second on-fixed period of any other phase. An exemplary motor module of the present invention includes the power converter and the motor described above. The output of the power converter is input to the motor.

Invention effect According to the exemplary invention, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, it is possible to suppress the temperature rise of the power converter and improve reliability.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same reference symbols are assigned to the same or corresponding parts in the drawings, and the description thereof will not be repeated.

A motor module 200 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2 . FIG. 1 is a block diagram of a motor module 200 according to an embodiment of the present invention. FIG. 2 is a circuit diagram showing the inverter unit 110 .

As shown in FIG. 1 , the motor module 200 includes a motor driving circuit 100 and a three-phase motor M. As shown in FIG. The three-phase motor M is driven by a motor drive circuit 100 . The three-phase motor M is, for example, a brushless DC motor. The three-phase motor M has a U-phase, a V-phase, and a W-phase. The output of the motor drive circuit 100 is input to the three-phase motor M. As shown in FIG. In addition, the motor drive circuit 100 corresponds to an example of a "power converter".

The motor drive circuit 100 controls the drive of the three-phase motor M. As shown in FIG. The motor drive circuit 100 includes an inverter unit 110 and a signal generation unit 120 .

The motor drive circuit 100 converts DC power into n-phase AC power. n is the number of phases of the AC output, which is an integer of 3 or more. In this embodiment, the motor drive circuit 100 converts direct current into three-phase alternating current. The motor drive circuit 100 includes n output terminals 102 . In this embodiment, the motor drive circuit 100 includes three output terminals 102 . The three output terminals 102 include an output terminal 102u, an output terminal 102v, and an output terminal 102w. The n output terminals 102 output n-phase output voltages and n-phase output currents. In the present embodiment, the three output terminals 102 output three-phase output voltages and three-phase output currents to the three-phase motor M. FIG. In detail, the output terminal 102u outputs the U-phase output voltage Vu and the U-phase output current Iu to the three-phase motor M. The output terminal 102v outputs a V-phase output voltage Vv and a V-phase output current Iv to the three-phase motor M. The output terminal 102w outputs a W-phase output voltage Vw and a W-phase output current Iw to the three-phase motor M. FIG.

As shown in FIG. 2 , the motor driving circuit 100 includes a first power supply terminal P, a second power supply terminal N, a capacitor C, n series bodies 112 and six temperature sensors 20 . In this embodiment, the motor drive circuit 100 includes a first power supply terminal P, a second power supply terminal N, a capacitor C, three series bodies 112 and six temperature sensors 20 . In more detail, in this embodiment, the motor drive circuit 100 includes an inverter unit 110, and the inverter unit 110 includes a first power supply terminal P, a second power supply terminal N, a capacitor C, three series bodies 112 and six temperature sensor 20. The inverter unit 110 also includes a DC voltage source B. In addition, the DC voltage source B may be located outside the inverter unit 110 .

The first voltage V1 is applied to the first power supply terminal P. The first input terminal P is connected to a DC voltage source B.

The second voltage V2 is applied to the second power supply terminal N. The second power supply terminal N is connected to the DC voltage source B. The second voltage V2 is lower than the first voltage V1.

The capacitor C is connected between the first power supply terminal P and the second power supply terminal N.

Two semiconductor switching elements are connected in series to the three series bodies 112 . The semiconductor switching element is, for example, an IGBT (Insulated Gate Bipolar Transistor). In addition, the semiconductor switching elements may also be other transistors such as field effect transistors. The three series bodies 112 include a series body 112u, a series body 112v and a series body 112w. The three serial bodies 112 are connected in parallel with each other. One end of each of the three series bodies 112 is connected to the first power supply terminal P. As shown in FIG. The other end of each of the three series bodies 112 is connected to the second power supply terminal N. As shown in FIG. To these semiconductor switching elements, a rectifying element D is connected in parallel with the first power terminal P side (upper side in the drawing) as a cathode and the second power supply terminal N side (lower side in the drawing) as an anode. In the case of using a field effect transistor as a semiconductor switching element, a parasitic diode may also be used as the above-mentioned rectifying element.

Each of the three series bodies 112 has a first semiconductor switching element and a second semiconductor switching element. In detail, the series body 112u has a first semiconductor switch element Up and a second semiconductor switch element Un. The series body 112v has a first semiconductor switching element Vp and a second semiconductor switching element Vn. The series body 112w has a first semiconductor switching element Wp and a second semiconductor switching element Wn.

The first semiconductor switching element Up, the first semiconductor switching element Vp, and the first semiconductor switching element Wp are connected to the first power supply terminal P. As shown in FIG. In other words, the first semiconductor switching element Up, the first semiconductor switching element Vp, and the first semiconductor switching element Wp are semiconductor switching elements on the high voltage side.

The second semiconductor switching element Un, the second semiconductor switching element Vn, and the second semiconductor switching element Wn are connected to the second power supply terminal N. In other words, the second semiconductor switching element Un, the second semiconductor switching element Vn, and the second semiconductor switching element Wn are semiconductor switching elements on the low voltage side.

The first semiconductor switching element and the second semiconductor switching element are connected at a connection point 114 . In detail, the first semiconductor switching element Up and the second semiconductor switching element Un are connected at the connection point 114u. The first semiconductor switching element Vp and the second semiconductor switching element Vn are connected at a connection point 114v. The first semiconductor switching element Wp and the second semiconductor switching element Wn are connected at a connection point 114w.

The respective connection points 114 of the three series bodies 112 are connected to the three output terminals 102 . In detail, the connection point 114u of the series body 112u is connected to the output terminal 102u. The connection point 114v of the series body 112v is connected to the output terminal 102v. The connection point 114w of the series body 112w is connected to the output terminal 102w.

A PWM signal is input to the first semiconductor switching element Up, the first semiconductor switching element Vp, and the first semiconductor switching element Wp. The PWM signal is output from the signal generator 120 . Hereinafter, in this specification, the PWM signal input to the first semiconductor switching element Up may be described as "UpPWM signal". In addition, the PWM signal input to the first semiconductor switching element Vp may be described as "VpPWM signal". The PWM signal input to the first semiconductor switching element Wp may be described as "WpPWM signal". The first semiconductor switching element Up, the first semiconductor switching element Vp, and the first semiconductor switching element Wp are switched between on and off at a frequency higher than that of the AC output. For example, the first semiconductor switching element Up, the first semiconductor switching element Vp, and the first semiconductor switching element Wp are turned on when the UpPWM signal, the VpPWM signal, and the WpPWM signal are at HIGH level, respectively. On the other hand, the first semiconductor switching element Up, the first semiconductor switching element Vp, and the first semiconductor switching element Wp are turned off when the UpPWM signal, the VpPWM signal, and the WpPWM signal are at a low (LOW) level, respectively.

A PWM signal is input to the second semiconductor switching element Un, the second semiconductor switching element Vn, and the second semiconductor switching element Wn. The PWM signal is output from the signal generator 120 . Hereinafter, in this specification, the PWM signal input to the 2nd semiconductor switching element Un may be described as "UnPWM signal". In addition, the PWM signal input to the second semiconductor switching element Vn may be described as "VnPWM signal". The PWM signal input to the second semiconductor switching element Wn is sometimes described as "WnPWM signal". The second semiconductor switching element Un, the second semiconductor switching element Vn, and the second semiconductor switching element Wn are switched between on and off at a frequency higher than that of the AC output. For example, the second semiconductor switching element Un, the second semiconductor switching element Vn, and the second semiconductor switching element Wn are turned on when the UnPWM signal, the VnPWM signal, and the WnPWM signal are at a high level, respectively. On the other hand, the second semiconductor switching element Un, the second semiconductor switching element Vn, and the second semiconductor switching element Wn are turned off when the UnPWM signal, the VnPWM signal, and the WnPWM signal are at low level, respectively.

As shown in FIG. 1 , the signal generation unit 120 has a carrier generation unit 122 , a voltage command value generation unit 124 , and a comparison unit 126 . The signal generation unit 120 is a hardware circuit composed of a processor such as a CPU (Central Processing Unit: central processing unit), an ASIC (Application Specific Integrated Circuit: dedicated integrated circuit), and the like. Furthermore, the processor of the signal generation unit 120 functions as the carrier wave generation unit 122 , the voltage command value generation unit 124 , and the comparison unit 126 by executing the computer program stored in the storage device.

The signal generation unit 120 controls the inverter unit 110 . Specifically, the signal generation unit 120 controls the inverter unit 110 by generating a PWM signal and outputting the PWM signal. More specifically, the signal generation unit 120 generates PWM signals to be input to the three serial bodies 112 respectively.

The carrier generation unit 122 generates a carrier signal. The carrier signal is, for example, a triangle wave. In addition, the carrier signal can also be a sawtooth wave.

The voltage command value generator 124 generates a voltage command value. The voltage command value corresponds to the voltage value output from the motor drive circuit 100 . That is, the voltage command value generating unit 124 generates voltage values corresponding to the output voltage Vu, the output voltage Vv, and the output voltage Vw as voltage command values.

The comparing unit 126 generates a PWM signal by comparing the carrier signal and the voltage command value.

The six temperature sensors 20 include a temperature sensor 21u, a temperature sensor 21v, a temperature sensor 21w, a temperature sensor 22u, a temperature sensor 22v, and a temperature sensor 22w. Six temperature sensors 20 are disposed near the semiconductor switching elements. Six temperature sensors 20 detect the temperature of the semiconductor switching elements. In detail, the temperature sensor 21u is disposed near the first semiconductor switching element Up. The temperature sensor 21u detects the temperature of the first semiconductor switching element Up. The temperature sensor 21v is disposed near the first semiconductor switching element Vp. The temperature sensor 21v detects the temperature of the first semiconductor switching element Vp. The temperature sensor 21w is disposed near the first semiconductor switching element Wp. The temperature sensor 21w detects the temperature of the first semiconductor switching element Wp. The temperature sensor 22u is disposed near the second semiconductor switching element Un. The temperature sensor 22u detects the temperature of the second semiconductor switching element Un. The temperature sensor 22v is disposed near the second semiconductor switching element Vn. The temperature sensor 22v detects the temperature of the second semiconductor switching element Vn. The temperature sensor 22w is disposed near the second semiconductor switching element Wn. The temperature sensor 22w detects the temperature of the second semiconductor switching element Wn.

Next, the output voltage will be described with reference to FIGS. 3A and 3B . FIG. 3A is a graph showing an output voltage Vu, an output voltage Vv, and an output voltage Vw. FIG. 3B is a graph showing switching loss. The switching loss of each element is shown as a relative value when the switching loss per switching element is set to 1 in the case of three-phase modulation in which all three phases are switched. FIG. 3A shows waveform example 1 of output voltage Vu, output voltage Vv, and output voltage Vw according to the embodiment of the present invention.

In FIG. 3A , the output voltage Vu is indicated by a solid line, the output voltage Vv is indicated by a dotted line, and the output voltage Vw is indicated by a dotted line. The vertical axis of FIG. 3A represents the voltage value normalized by the input voltage V1-V2, and the output voltage of each phase takes the value within the range of 0-1. The output voltage 0 is a state where the output voltage substantially matches V2, and the output voltage 1 is a state where the output voltage substantially matches V1. Furthermore, this value also represents the ratio of the ON time of the first semiconductor switching element of each phase to the PWM period, that is, the duty value. When the switching operation of the second semiconductor switching element is performed, the ratio of the on-time of the second semiconductor switching element to the PWM cycle is obtained by subtracting the value on the vertical axis from 1. When switching both the first semiconductor switching element and the second semiconductor switching element, an appropriate dead time is provided to prevent both from being turned on at the same time, and the switching operation is performed complementary. The horizontal axis of FIG. 3A represents the electrical rotation angle of the motor, and the unit is degree.

Waveform example 1 of the output voltage Vu, the output voltage Vv, and the output voltage Vw according to the embodiment of the present invention will be described with reference to FIG. 3A .

As shown in Figure 3A, waveform example 1 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 1 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 30 degrees to 150 degrees. In addition, the waveform is such that the output of any one phase is fixed at 0 within an electrical angle of 0 degrees to an electrical angle of 30 degrees and an electrical angle of 150 degrees to an electrical angle of 360 degrees. In this specification, the period during which the output of any one phase is fixed to 1 may be described as "high-side ON application period T3". In addition, in this specification, the period in which the output of any one phase is fixed to 0 may be described as "low-side ON application period T4". In waveform example 1, the high side ON application period T3 is the electrical angle from 30 degrees to 150 degrees. In addition, in waveform example 1, the low-side ON application period T4 is the electrical angle of 0 degrees to the electrical angle of 30 degrees and the electrical angle of 150 degrees to the electrical angle of 360 degrees. Preferably, the two-phase difference between the output voltage Vu, the output voltage Vv and the output voltage Vw is a sine wave. Therefore, a sine wave can be output as a voltage between output terminals. As a result, for example, when driving a motor, an operation with less noise and less uneven torque can be realized. For example, by subtracting a common bias waveform from sine waves each having a phase difference of 2π/n, the output voltage waveform of each phase can be obtained, and the output voltage waveform of each phase can be set as a voltage command value.

As shown in FIG. 3A , during one cycle of the n-phase AC output, at least one phase of the AC output has a first on-fixed period T1 and a second on-fixed period T2 . The first on-fixed period T1 is a period in which the first semiconductor switching element is kept on. The second on-fixed period T2 is a period in which the second semiconductor switching element is kept on.

In waveform example 1, the first on-fixed period T1 includes the first on-fixed period T1u. The first on-fixed period T1u is a period in which the first semiconductor switching element Up is kept on. In waveform example 1, the first on-fixed period T1u is from an electrical angle of 30 degrees to an electrical angle of 150 degrees.

The first on-fixed period T1 indicates that only the first semiconductor switching element of one of the n phases is on-fixed, and in all the other phases of the n phases, the first semiconductor switching element and the second semiconductor switching element The period during which at least one side performs switching operations. In waveform example 1, in the first on-fixed period T1u, only the first semiconductor switching element Up of the U-phase among the three phases is on-fixed, and the first semiconductor switching element Vp and the first semiconductor switching element of the V-phase among the three phases are constant. At least one of the two semiconductor switching elements Vn and at least one of the W-phase first semiconductor switching element Wp and the second semiconductor switching element Wn perform a switching operation.

In waveform example 1, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 1, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 1, the electrical angle of 0° to 30° and the electrical angle of 330° to 360° are the second on-fixed period T2v. In waveform example 1, the second on-fixed period T2w is from an electrical angle of 150 degrees to an electrical angle of 210 degrees.

The second on-fixed period T2 indicates that only the second semiconductor switching element of one of the n phases is on-fixed, and in all the other phases of the n phases, the first semiconductor switching element and the second semiconductor switching element The period during which at least one side performs switching operations. In waveform example 1, only the second semiconductor switching element Un of the U-phase among the three phases is on-fixed during the second on-fixed period T2u, and the first semiconductor switching element Vp and the first semiconductor switching element Vp of the V-phase among the three phases are constant. At least one of the two semiconductor switching elements Vn and at least one of the W-phase first semiconductor switching element Wp and the second semiconductor switching element Wn perform a switching operation. In waveform example 1, only the second semiconductor switching element Vn of the V-phase among the three phases is on-fixed during the second on-fixed period T2v, and the first semiconductor switching element Up and the first semiconductor switching element Up of the U-phase among the three phases are constant. At least one of the two semiconductor switching elements Un and at least one of the W-phase first semiconductor switching element Wp and the second semiconductor switching element Wn perform a switching operation. In waveform example 1, in the second on-fixed period T2w, only the second semiconductor switching element Wn of the W-phase among the three phases is on-fixed, and the first semiconductor switching element Up and the first semiconductor switching element of the U-phase of the three phases are up and At least one of the two semiconductor switching elements Un and at least one of the V-phase first semiconductor switching element Vp and the second semiconductor switching element Vn perform a switching operation.

One cycle of the AC output is divided into a plurality of periods, and the plurality of periods are respectively the first fixed-on period of any phase or the second fixed-on period of any phase. In detail, in the waveform example 1, the electrical angle of 0 degrees to the electrical angle of 30 degrees is the second on-fixed period T2v. In waveform example 1, the first on-fixed period T1u is from an electrical angle of 30 degrees to an electrical angle of 150 degrees. In waveform example 1, the second on-fixed period T2w is from an electrical angle of 150 degrees to an electrical angle of 210 degrees. In waveform example 1, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 1, the electrical angle of 330° to 360° is the second on-fixed period T2v. Therefore, since the switching operation of one phase is always stopped, efficient temperature rise suppression can be realized, and the reliability of the inverter can be improved.

The motor drive circuit 100 has a protection operation mode. The protection operation mode has at least one of the first on-fixed period T1 and the second on-fixed period T2. In the protection action mode, in at least one of the n phases, the first on-fixed period T1 is different from that of any other phase, or the second on-fixed period T2 is different from that of any other phase. The second on-fixed periods T2 of the phases are different. The case where any other phase does not have the first on-fixed period T1 and the second on-fixed period T2 is also included here.

In waveform example 1, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. In detail, in waveform example 1, the first on-fixed period T1u is 120 degrees, whereas the first on-fixed period T1v and the first on-fixed period T1w are absent. That is, in waveform example 1, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 3B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 1, in the U phase of the three phases, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in waveform example 1, the second on-fixed period T2u is 120 degrees, whereas the second on-fixed period T2v and the second on-fixed period T2w are 60 degrees. That is, in waveform example 1, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 3B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 1 to 3B , in waveform example 1, in the protection operation mode, in at least one phase of the n phases, the first on-fixed period T1 is equal to the first on-off period of the other phases. The fixed period T1 is different. Therefore, heat generation of the first semiconductor switching element of the phase having the first fixed on period longer than the first fixed on period T1 of the other phase can be suppressed. Also, in at least one of the n phases, the second on-fixed period T2 is different from the second on-fixed period T2 of the other phases. Therefore, heat generation of the second semiconductor switching element of the phase having the second fixed on period longer than the second fixed on period T2 of the other phase can be suppressed. In addition, especially in waveform example 1, in at least one phase, the first on-fixed period T1 is different from the first on-fixed period T1 of other phases, and in at least one phase, the second on-fixed period T2 is different from that of other phases. The second on-fixed period T2 of the other phases is different. Therefore, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, it is possible to suppress the temperature rise of the power converter (inverter) and improve reliability. For example, when the temperature of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase are likely to rise due to switching operations due to the presence of heat-generating parts nearby or the location with poor heat dissipation efficiency, etc., by using waveform example 1 The method of suppressing the switching heat generation of the above two elements can prevent the above two elements from excessive temperature rise, thereby improving the reliability of the power converter (inverter). In waveform example 1, the heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in waveform example 1, as shown in FIG. 3B , by setting the second on-fixed period T2v of the V-phase and the second on-fixed period T2w of the W-phase, the second semiconductor switching element of the V-phase can also be suppressed at the same time. Vn and heat generation of the second semiconductor switching element Wn of the W phase. Therefore, in an environment where the temperature of the U-phase is most likely to rise, and then the temperature of the second semiconductor switching elements of other phases is likely to rise, overheating of these elements is prevented and reliability is improved.

Also, the first on-fixed period of any phase is longer than the first on-fixed period of the other phases, and the second on-fixed period of any phase is longer than the second on-fixed period of the other phases. Therefore, when the temperature of a specific phase becomes a problem due to a problem of the cooling water channel or the like, heat generation of the phase can be suppressed, thereby improving the reliability of the inverter. Alternatively, when a sudden stop (stall) occurs and the current continuously flows through the first semiconductor switching element of a certain phase and the second semiconductor switching element of another phase to increase the temperature, by exiting the sudden stop and starting the operation By performing the above operation, the heat generation of the semiconductor switching element after the sudden stop temperature rise can be suppressed, and the temperature can be rapidly lowered, thereby improving the reliability of the inverter.

The waveform examples of the embodiment of the present invention will be further described with reference to FIGS. 4 to 15B . FIG. 4 is a table showing the relationship between waveform examples and switching loss. In FIG. 4 , UH represents the switching loss of the U-phase first semiconductor switching element Up. UL represents the switching loss of the U-phase second semiconductor switching element Un. VH represents the switching loss of the V-phase first semiconductor switching element Vp. VL represents the switching loss of the V-phase second semiconductor switching element Vn. WH represents the switching loss of the first semiconductor switching element Wp of the W phase. WL represents the switching loss of the W-phase second semiconductor switching element Wn.

As shown in Figure 4, in waveform examples 1 to 12, UH is 0.13, and UL is 0.13, that is, in waveform examples 1 to 12, the first semiconductor switching element Up of the U phase and the second semiconductor switching element of the U phase An example of a waveform with a small switching loss of the semiconductor switching element Un. That is, waveform examples 1 to 12 are examples of waveforms capable of protecting the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un. In this specification, a waveform capable of protecting a first semiconductor switching element (eg Up) of a certain phase (eg U phase) and a second semiconductor switching element (eg Un) of the same phase may be described as a UH_UL protection waveform.

Waveform example 2 will be described with reference to FIGS. 5A and 5B . FIG. 5A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 5B is a graph showing switching loss.

As shown in Figure 5A, waveform example 2 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 2 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 0 degrees to an electrical angle of 180 degrees. In addition, the waveform example 2 is a waveform in which the output of any one phase is fixed at 0 within an electrical angle of 180 degrees to an electrical angle of 360 degrees. In waveform example 2, the high-side ON application period T3 is the electrical angle from 0° to 180°. In addition, in waveform example 2, the low-side ON application period T4 is from an electrical angle of 180 degrees to an electrical angle of 360 degrees.

In waveform example 2, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 2, the first on-fixed period T1u is from an electrical angle of 30 degrees to an electrical angle of 150 degrees. In waveform example 2, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 180 degrees. In waveform example 2, the electrical angle of 0° to 30° is the first on-fixed period T1w.

In waveform example 2, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 2, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In the waveform example 2, the second on-fixed period T2v is from an electrical angle of 330 degrees to an electrical angle of 360 degrees. In waveform example 2, the second on-fixed period T2w is from an electrical angle of 180 degrees to an electrical angle of 210 degrees.

In waveform example 2, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 2, the first on-fixed period T1u is 120 degrees, whereas the first on-fixed period T1v and the first on-fixed period T1w are 30 degrees. That is, in waveform example 2, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 5B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 2, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in the waveform example 2, the second on-fixed period T2u is 120 degrees, whereas the second on-fixed period T2v and the second on-fixed period T2w are 30 degrees. That is, in waveform example 2, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 5B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 5A and 5B , in waveform example 2, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In the waveform example 2, heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

Furthermore, in waveform example 2, as shown in FIG. 5B , the V-phase first semiconductor switching element Vp, the V-phase second semiconductor switching element Vn, the W-phase first semiconductor switching element Wp, and the W-phase The heat generation of the second semiconductor switching element Wn. In addition, waveform example 2 can be replaced by waveform example 9 ( FIG. 12 ), which will be described later, which has a higher effect of suppressing heat generation.

Waveform example 3 will be described with reference to FIGS. 6A and 6B . FIG. 6A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 6B is a graph showing switching loss.

As shown in Figure 6A, waveform example 3 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 3 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 0° to an electrical angle of 210° and an electrical angle of 330° to 360°. In addition, the waveform example 3 is a waveform in which the output of any one phase is fixed at 0 within an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 3, the high side ON application period T3 is the electrical angle from 0° to 210° and the electrical angle from 330° to 360°. In addition, in waveform example 3, the low-side ON application period T4 is from an electrical angle of 210 degrees to an electrical angle of 330 degrees.

In waveform example 3, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 3, the first on-fixed period T1u is from an electrical angle of 30 degrees to an electrical angle of 150 degrees. In waveform example 3, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 210 degrees. In the waveform example 3, the electrical angle of 0° to 30° and the electrical angle of 330° to 360° are the first ON fixed period T1w.

In waveform example 3, the second on-fixed period T2 includes a second on-fixed period T2u. In waveform example 3, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees.

In the waveform example 3, in the U phase among the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 3, the first on-fixed period T1u is 120 degrees, whereas the first on-fixed period T1v and the first on-fixed period T1w are 60 degrees. That is, in waveform example 3, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 6B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 3, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in the waveform example 3, the second on-fixed period T2u is 120 degrees, whereas the second on-fixed period T2v and the second on-fixed period T2w are absent. That is, in waveform example 3, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 6B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 6A and 6B , in waveform example 3, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In the waveform example 3, heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in waveform example 3, as shown in FIG. 6B , heat generation of the V-phase first semiconductor switching element Vp and the W-phase first semiconductor switching element Wp can be simultaneously suppressed.

Waveform example 4 will be described with reference to FIGS. 7A and 7B . FIG. 7A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 7B is a graph showing switching loss.

As shown in Figure 7A, waveform example 4 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 4 is a waveform in which the output of any phase is fixed at 1 within an electrical angle of 30 degrees to 180 degrees. In addition, waveform example 4 is a waveform in which the output of any one phase is fixed at 0 within an electrical angle of 0 degrees to an electrical angle of 30 degrees and an electrical angle of 180 degrees to an electrical angle of 360 degrees. In the waveform example 4, the high-side ON application period T3 is from an electrical angle of 30 degrees to an electrical angle of 180 degrees. In addition, in waveform example 4, the low-side ON application period T4 is the electrical angle of 0 degrees to the electrical angle of 30 degrees and the electrical angle of 180 degrees to the electrical angle of 360 degrees.

In waveform example 4, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1v. In waveform example 4, the first on-fixed period T1u is from an electrical angle of 30 degrees to an electrical angle of 150 degrees. In the waveform example 4, the electrical angle of 150° to 180° is the first on-fixed period T1v.

In waveform example 4, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 4, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 4, the electrical angle of 0° to 30° and the electrical angle of 330° to 360° are the second on-fixed period T2v. In waveform example 4, the second on-fixed period T2w is from an electrical angle of 180 degrees to an electrical angle of 210 degrees.

In waveform example 4, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. In detail, in waveform example 4, the first on-fixed period T1u is 120 degrees, whereas the first on-fixed period T1v is 30 degrees, and there is no first on-fixed period T1w. That is, in waveform example 4, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 7B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 4, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in the waveform example 4, the second on-fixed period T2u is 120 degrees, while the second on-fixed period T2v is 60 degrees, and the second on-fixed period T2w is 30 degrees. That is, in waveform example 4, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 7B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 7A and 7B , in waveform example 4, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In the waveform example 4, heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in waveform example 4, as shown in FIG. 7B , heat generation of the V-phase first semiconductor switching element Vp, the V-phase second semiconductor switching element Vn, and the W-phase second semiconductor switching element Wn can be simultaneously suppressed. In addition, waveform example 4 can be replaced by waveform example 6 ( FIG. 9 ), which will be described later, which has a higher effect of suppressing heat generation.

Waveform Example 5 will be described with reference to FIGS. 8A and 8B . FIG. 8A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 8B is a graph showing switching loss.

As shown in Figure 8A, waveform example 5 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 5 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 30 degrees to 210 degrees. In addition, waveform example 5 is a waveform in which the output of any phase is fixed at 0 within an electrical angle of 0° to an electrical angle of 30° and an electrical angle of 210° to 360°. In waveform example 5, the high-side ON application period T3 is from an electrical angle of 30 degrees to an electrical angle of 210 degrees. In addition, in the waveform example 5, the low-side ON application period T4 is the electrical angle of 0 degrees to the electrical angle of 30 degrees and the electrical angle of 210 degrees to the electrical angle of 360 degrees.

In waveform example 5, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1v. In waveform example 5, the first on-fixed period T1u is from an electrical angle of 30 degrees to an electrical angle of 150 degrees. In waveform example 5, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 210 degrees.

In waveform example 5, the second on-fixed period T2 includes a second on-fixed period T2u and a second on-fixed period T2v. In waveform example 5, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In the waveform example 5, the electrical angle of 0° to 30° and the electrical angle of 330° to 360° are the second on-fixed period T2v.

In waveform example 5, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. In detail, in the waveform example 5, the first on-fixed period T1u is 120 degrees, whereas the first on-fixed period T1v is 60 degrees and there is no first on-fixed period T1w. That is, in waveform example 5, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 8B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 5, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in waveform example 5, the second fixed ON period T2u is 120 degrees, whereas the second fixed ON period T2v is 60 degrees, and there is no second fixed ON period T2w. That is, in waveform example 5, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 8B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 8A and 8B , in waveform example 5, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 5, the heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in waveform example 5, as shown in FIG. 8B , heat generation of the V-phase first semiconductor switching element Vp and the V-phase second semiconductor switching element Vn can be simultaneously suppressed.

Waveform Example 6 will be described with reference to FIGS. 9A and 9B . FIG. 9A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 9B is a graph showing switching loss.

As shown in Figure 9A, waveform example 6 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 6 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 30 degrees to 150 degrees and an electrical angle of 180 degrees to 210 degrees. In addition, Waveform Example 6 is a waveform in which any The phase output is fixed at 0. In waveform example 6, the high-side ON application period T3 is an electrical angle of 30 degrees to an electrical angle of 150 degrees and an electrical angle of 180 degrees to an electrical angle of 210 degrees. In addition, in waveform example 6, the electrical angle of 0° to 30°, the electrical angle of 150° to 180°, and the electrical angle of 210° to 360° are low-side ON application periods. T4.

In waveform example 6, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1v. In waveform example 6, the first on-fixed period T1u is from an electrical angle of 30 degrees to an electrical angle of 150 degrees. In waveform example 6, the first on-fixed period T1v is from an electrical angle of 180 degrees to an electrical angle of 210 degrees.

In waveform example 6, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 6, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 6, the second on-fixed period T2v is the electrical angle of 330 degrees to the electrical angle of 360 degrees and the electrical angle of 0 degrees to the electrical angle of 30 degrees. In waveform example 6, the second on-fixed period T2w is from an electrical angle of 150 degrees to an electrical angle of 180 degrees.

In waveform example 6, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. In detail, in waveform example 6, the first on-fixed period T1u is 120 degrees, whereas the first on-fixed period T1v is 30 degrees, and there is no first on-fixed period T1w. That is, in waveform example 6, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 9B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 6, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in waveform example 6, the second fixed ON period T2u is 120 degrees, whereas the second fixed ON period T2v is 60 degrees, and the second fixed ON period T2w is 30 degrees. That is, in waveform example 6, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 9B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 9A and 9B , in waveform example 6, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 6, the heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in waveform example 6, as shown in FIG. 9B , heat generation of the V-phase first semiconductor switching element Vp, the V-phase second semiconductor switching element Vn, and the W-phase second semiconductor switching element Wn can be simultaneously suppressed.

Waveform example 7 will be described with reference to FIGS. 10A and 10B . FIG. 10A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 10B is a graph showing switching loss.

As shown in Figure 10A, waveform example 7 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 7 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 0° to an electrical angle of 150° and an electrical angle of 180° to 210°. In addition, waveform example 7 is a waveform in which the output of any one phase is fixed at 0 within an electrical angle of 150° to 180° and an electrical angle of 210° to 360°. In waveform example 7, the high-side ON application period T3 is the electrical angle of 0 degrees to the electrical angle of 150 degrees and the electrical angle of 180 degrees to the electrical angle of 210 degrees. In addition, in the waveform example 7, the low-side ON application period T4 is the electrical angle of 150 degrees to the electrical angle of 180 degrees and the electrical angle of 210 degrees to the electrical angle of 360 degrees.

In waveform example 7, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 7, the first on-fixed period T1u is from an electrical angle of 30 degrees to an electrical angle of 150 degrees. In the waveform example 7, the first on-fixed period T1v is from an electrical angle of 180 degrees to an electrical angle of 210 degrees. In waveform example 7, the electrical angle of 0° to 30° is the first on-fixed period T1w.

In waveform example 7, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 7, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In the waveform example 7, the second on-fixed period T2v is from an electrical angle of 330 degrees to an electrical angle of 360 degrees. In waveform example 7, the second on-fixed period T2w is from an electrical angle of 150 degrees to an electrical angle of 180 degrees.

In waveform example 7, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 7, the first on-fixed period T1u is 120 degrees, whereas the first on-fixed period T1v and the first on-fixed period T1w are 30 degrees. That is, in waveform example 7, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 10B , the switching loss of the U-phase first semiconductor switching element Up (H (high side)) is smaller than that of the V-phase and W-phase.

In waveform example 7, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in the waveform example 7, the second on-fixed period T2u is 120 degrees, whereas the second on-fixed period T2v and the second on-fixed period T2w are 30 degrees. That is, in waveform example 7, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 10B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 10A and 10B , in waveform example 7, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 7, the heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in waveform example 7, as shown in FIG. 10B , the V-phase first semiconductor switching element Vp, the V-phase second semiconductor switching element Vn, the W-phase first semiconductor switching element Wp, and the W-phase The heat generation of the second semiconductor switching element Wn. In addition, waveform example 7 can be replaced by waveform example 9 ( FIG. 12 ), which will be described later, which has a higher effect of suppressing heat generation.

Waveform example 8 will be described with reference to FIGS. 11A and 11B . FIG. 11A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 11B is a graph showing switching loss.

As shown in Figure 11A, waveform example 8 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 8 has the following waveforms, that is, within the electrical angle of 0 degrees to 150 degrees, the electrical angle of 180 degrees to 210 degrees, and the electrical angle of 330 degrees to 360 degrees, any The output of one phase is fixed at 1. In addition, waveform example 8 is a waveform in which the output of any one phase is fixed at 0 within an electrical angle of 150° to 180° and an electrical angle of 210° to 330°. In waveform example 8, the high-side ON application period T3 is the electrical angle of 0° to 150°, the electrical angle of 180° to 210°, and the electrical angle of 330° to 360°. In addition, in the waveform example 8, the low-side ON application period T4 is the electrical angle of 150 degrees to the electrical angle of 180 degrees and the electrical angle of 210 degrees to the electrical angle of 330 degrees.

In waveform example 8, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 8, the first on-fixed period T1u is from an electrical angle of 30 degrees to an electrical angle of 150 degrees. In the waveform example 8, the first on-fixed period T1v is from an electrical angle of 180 degrees to an electrical angle of 210 degrees. In the waveform example 8, the electrical angle of 0° to 30° and the electrical angle of 330° to 360° are the first on-fixed periods T1w.

In waveform example 8, the second on-fixed period T2 includes a second on-fixed period T2u and a second on-fixed period T2w. In waveform example 8, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In the waveform example 8, the second on-fixed period T2w is from an electrical angle of 150 degrees to an electrical angle of 180 degrees.

In waveform example 8, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. In detail, in waveform example 8, the first on-fixed period T1u is 120 degrees, whereas the first on-fixed period T1v is 30 degrees, and the first on-fixed period T1w is 60 degrees. That is, in waveform example 8, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 11B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 8, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. In detail, in the waveform example 8, the second on-fixed period T2u is 120 degrees, but there is no second on-fixed period T2v, and the second on-fixed period T2w is 30 degrees. That is, in waveform example 8, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 11B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 11A and 11B , in waveform example 8, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 8, the heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in waveform example 8, as shown in FIG. 11B , heat generation of the V-phase first semiconductor switching element Vp, the W-phase first semiconductor switching element Wp, and the W-phase second semiconductor switching element Wn can be simultaneously suppressed.

Waveform Example 9 will be described with reference to FIGS. 12A and 12B . FIG. 12A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 12B is a graph showing switching loss.

As shown in Figure 12A, waveform example 9 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, the waveform example 9 has the following waveforms, that is, any electrical angle within the electrical angle of 30 degrees to 150 degrees, the electrical angle of 180 degrees to 210 degrees, and the electrical angle of 330 degrees to 360 degrees. The output of one phase is fixed at 1. In addition, Waveform Example 9 shows a waveform in which any The phase output is fixed at 0. In waveform example 9, the high-side ON application period T3 is the electrical angle of 30 degrees to 150 degrees, the electrical angle of 180 degrees to 210 degrees, and the electrical angle of 330 degrees to 360 degrees. In addition, in waveform example 9, the electrical angle of 0° to 30°, the electrical angle of 150° to 180°, and the electrical angle of 210° to 330° are low-side ON application periods. T4.

In waveform example 9, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 9, the first on-fixed period T1u is from an electrical angle of 30 degrees to an electrical angle of 150 degrees. In the waveform example 9, the electrical angle of 180° to 210° is the first on-fixed period T1v. In the waveform example 9, the first on-fixed period T1w is from an electrical angle of 330 degrees to an electrical angle of 360 degrees.

In waveform example 9, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 9, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 9, the electrical angle of 0° to 30° is the second on-fixed period T2v. In the waveform example 9, the electrical angle of 150° to 180° is the second on-fixed period T2w.

In waveform example 9, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 9, the first on-fixed period T1u is 120 degrees, whereas the first on-fixed period T1v and the first on-fixed period T1w are 30 degrees. That is, in waveform example 9, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 12B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 9, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. In detail, in waveform example 9, the second on-fixed period T2u is 120 degrees, whereas the second on-fixed period T2v and the second on-fixed period T2w are 30 degrees. That is, in waveform example 9, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 12B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 12A and 12B , in waveform example 9, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 9, the heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in waveform example 9, as shown in FIG. 12B , the V-phase first semiconductor switching element Vp, the V-phase second semiconductor switching element Vn, the W-phase first semiconductor switching element Wp, and the W-phase The heat generation of the second semiconductor switching element Wn.

Waveform example 10 will be described with reference to FIGS. 13A and 13B . FIG. 13A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 3B is a graph showing switching loss.

As shown in FIG. 13A , waveform example 10 is the following waveform. According to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0. In detail, waveform example 10 is a waveform in which the output of any phase is fixed at 1 within an electrical angle of 0° to an electrical angle of 150° and an electrical angle of 330° to 360°. In addition, waveform example 10 is a waveform in which the output of any one phase is fixed at 0 within an electrical angle of 150 degrees to an electrical angle of 330 degrees. In waveform example 10, the high-side ON application period T3 is the electrical angle of 0 degrees to the electrical angle of 150 degrees and the electrical angle of 330 degrees to the electrical angle of 360 degrees. In addition, in waveform example 10, the low-side ON application period T4 is between an electrical angle of 150 degrees and an electrical angle of 330 degrees.

In waveform example 10, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1w. In waveform example 10, the first on-fixed period T1u is from an electrical angle of 30 degrees to an electrical angle of 150 degrees. In waveform example 10, an electrical angle of 0 degrees to an electrical angle of 30 degrees and an electrical angle of 330 degrees to an electrical angle of 360 degrees are the first on-fixed period T1w.

In waveform example 10, the second on-fixed period T2 includes a second on-fixed period T2u and a second on-fixed period T2w. In waveform example 10, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 10, the second on-fixed period T2w is from an electrical angle of 150 degrees to an electrical angle of 210 degrees.

In waveform example 10, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. In detail, in waveform example 10, the first on-fixed period T1u is 120 degrees, but there is no first on-fixed period T1v, and the first on-fixed period T1w is 60 degrees. That is, in waveform example 10, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 13B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 10, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. In detail, in the waveform example 10, the second on-fixed period T2u is 120 degrees, but there is no second on-fixed period T2v, and the second on-fixed period T2w is 60 degrees. That is, in waveform example 10, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 13B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 13A and 13B , in waveform example 10, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 10, the heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be suppressed at the same time.

In addition, in waveform example 10, as shown in FIG. 13B , heat generation of the W-phase first semiconductor switching element Wp and the W-phase second semiconductor switching element Wn can be simultaneously suppressed.

Waveform example 11 will be described with reference to FIGS. 14A and 14B . FIG. 14A is a graph showing the output voltage Vu, the output voltage Vv, and the output voltage Vw. FIG. 14B is a graph showing switching loss.

As shown in Figure 14A, waveform example 11 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 11 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 30° to 210° and an electrical angle of 330° to 360°. In addition, waveform example 11 is a waveform in which the output of any phase is fixed at 0 within an electrical angle of 0 degrees to an electrical angle of 30 degrees and an electrical angle of 210 degrees to 330 degrees. In waveform example 11, the high-side ON application period T3 is an electrical angle of 30 degrees to an electrical angle of 210 degrees and an electrical angle of 330 degrees to an electrical angle of 360 degrees. In addition, in waveform example 11, the low-side ON application period T4 is the electrical angle of 0 degrees to the electrical angle of 30 degrees and the electrical angle of 210 degrees to the electrical angle of 330 degrees.

In waveform example 11, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 11, the first on-fixed period T1u is from an electrical angle of 30 degrees to an electrical angle of 150 degrees. In waveform example 11, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 210 degrees. In waveform example 11, the first on-fixed period T1w is from an electrical angle of 330 degrees to an electrical angle of 360 degrees.

In waveform example 11, the second on-fixed period T2 includes a second on-fixed period T2u and a second on-fixed period T2v. In waveform example 11, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 11, the electrical angle of 0° to 30° is the second on-fixed period T2v.

In waveform example 11, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 11, the first on-fixed period T1u is 120 degrees, whereas the first on-fixed period T1v is 60 degrees, and the first on-fixed period T1w is 30 degrees. That is, in waveform example 11, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 14B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 11, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in waveform example 11, the second fixed ON period T2u is 120 degrees, whereas the second fixed ON period T2v is 30 degrees, and there is no second fixed ON period T2w. That is, in waveform example 11, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 14B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 14A and 14B , in waveform example 11, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 11, the heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

Furthermore, in waveform example 11, as shown in FIG. 14B , heat generation of the V-phase first semiconductor switching element Vp, the V-phase second semiconductor switching element Vn, and the W-phase first semiconductor switching element Wp can be simultaneously suppressed.

Waveform example 12 will be described with reference to FIGS. 15A and 15B . FIG. 15A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 15B is a graph showing switching loss.

As shown in Figure 15A, waveform example 12 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 12 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 30° to 150° and an electrical angle of 330° to 360°. In addition, waveform example 12 is a waveform in which the output of any phase is fixed at 0 within an electrical angle of 0° to an electrical angle of 30° and an electrical angle of 150° to 330°. In waveform example 12, the high-side ON application period T3 is an electrical angle of 30 degrees to an electrical angle of 150 degrees and an electrical angle of 330 degrees to an electrical angle of 360 degrees. In addition, in the waveform example 12, the low-side ON application period T4 is the electrical angle of 0° to the electrical angle of 30° and the electrical angle of 150° to the electrical angle of 330°.

In waveform example 12, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1w. In waveform example 12, the first on-fixed period T1u is from an electrical angle of 30 degrees to an electrical angle of 150 degrees. In waveform example 12, the first on-fixed period T1w is from an electrical angle of 330 degrees to an electrical angle of 360 degrees.

In waveform example 12, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 12, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 12, the electrical angle of 0° to 30° is the second on-fixed period T2v. In waveform example 12, the second on-fixed period T2w is from an electrical angle of 150 degrees to an electrical angle of 210 degrees.

In waveform example 12, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 12, the first on-fixed period T1u is 120 degrees, whereas the first on-fixed period T1v is not provided and the first on-fixed period T1w is 30 degrees. That is, in waveform example 12, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 15B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 12, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in waveform example 12, the second fixed ON period T2u is 120 degrees, whereas the second fixed ON period T2v is 30 degrees, and the second fixed ON period T2w is 60 degrees. That is, in waveform example 12, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 15B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 15A and 15B , in the waveform example 12, similarly to the waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 12, the heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in waveform example 12, as shown in FIG. 15B , heat generation of the V-phase second semiconductor switching element Vn, the W-phase first semiconductor switching element Wp, and the W-phase second semiconductor switching element Wn can be simultaneously suppressed.

The switching loss when the fixed period of the U phase is changed will be described with reference to FIG. 16 . FIG. 16 is a graph showing switching loss.

As shown in FIG. 16 , in the U phase, the high-side first on-fixed period T1u is set to an electrical angle of 30 degrees to 150 degrees, and the low-side second on-fixed period T2u is set to When the electrical angle is 210 degrees to 330 degrees, the switching loss is 0.13. That is, in the U phase, when the high-side first constant ON period T1u is set to 120 degrees and the low-side second constant ON period T2u is set to 120 degrees, the switching loss is 0.13.

In the U phase, the high-side first constant ON period T1u is set at an electrical angle of 40 degrees to 140 degrees, and the low-side second constant ON period T2u is set at an electrical angle of 220 degrees to 140 degrees. When the angle is 330 degrees, the switching loss is 0.22. That is, in the U phase, when the high-side first on-fixed period T1u is 120 degrees and the low-side second on-fixed period T2u is 100 degrees, the switching loss is 0.22.

In the U phase, the high-side first constant ON period T1u is set at an electrical angle of 50 degrees to 130 degrees, and the low-side second constant ON period T2u is set at an electrical angle of 230 degrees to 130 degrees. When the angle is 310 degrees, the switching loss is 0.35. That is, in the U phase, when the high-side first constant ON period T1u is 80 degrees and the low-side second ON constant period T2u is 100 degrees, the switching loss is 0.22.

In the U phase, the high-side first constant ON period T1u is set at an electrical angle of 50 degrees to 130 degrees, and the low-side second constant ON period T2u is set at an electrical angle of 230 degrees to electrical angles. When the angle is 310 degrees, the switching loss is 0.35. That is, in the U phase, when the high-side first on-fixed period T1u is set to 80 degrees and the low-side second on-fixed period T2u is set to 80 degrees, the switching loss is 0.35.

In the U phase, the high-side first constant ON period T1u is set at an electrical angle of 60 degrees to 120 degrees, and the low-side second constant ON period T2u is set at an electrical angle of 240 degrees to 120 degrees. In the case of an angle of 300 degrees, the switching loss is 0.50. That is, in the U phase, when the high-side first on-fixed period T1u is 60 degrees and the low-side second on-fixed period T2u is 60 degrees, the switching loss is 0.50.

As described above with reference to FIG. 16 , it is preferable that both the first on-fixed period T1u and the second on-fixed period T2u are longer than π/3 (60 degrees) and not more than 2π/3 (120 degrees). More preferably, it is longer than 4π/9 (80 degrees) and 2π/3 (120 degrees) or less.

Next, the switching of the UH_UL guard waveform will be further described with reference to FIG. 17 . FIG. 17 is a diagram for explaining switching of UH_UL guard waveforms.

In Fig. 17, the output voltage waveform and switching loss correspond to (c) Waveform Example 3 (Fig. 6A and Fig. 6B), (i) Waveform Example 9 (Fig. 12A and Fig. 12B), (a) Waveform Example 1 (Figure 3A and Figure 3B).

(c) Waveform example 3 shown in the figure on the left is a waveform example obtained by extending the first on-fixed period T1v and the first on-fixed period T1w. In other words, it is an example of a waveform in which suppression of heat generation on the high side is emphasized.

(i) Waveform example 3 shown in the center figure is a waveform example in which the first on-fixed period T1v, the first on-fixed period T1w, the second on-fixed period T2v, and the second on-fixed period T2w are equalized. That is, it is an example of a waveform in which portions other than the first fixed ON period T1u and the second fixed ON period T2u are equalized.

(a) Waveform example 1 shown in the figure on the right is a waveform example obtained by extending the second on-fixed period T2v and the second on-fixed period T2w. In other words, it is an example of a waveform in which suppression of heat generation on the low side is emphasized.

As the diagram shifts to the left, the first on-fixed period T1v and the first on-fixed period T1w become longer. Therefore, the switching loss of the V-phase first semiconductor switching element Vp (high side) and the W-phase first semiconductor switching element Wp (high side) decreases as the diagram shifts to the left.

On the other hand, the second on-fixed period T2v and the second on-fixed period T2w become longer as the graph shifts to the right. Therefore, the switching loss of the V-phase second semiconductor switching element Vn (low side) and the W-phase second semiconductor switching element Wn (low side) decreases as the diagram shifts to the left.

Next, the switching of the UH_UL guard waveform will be further described with reference to FIG. 16 . FIG. 16 is a diagram for explaining switching of UH_UL guard waveforms.

In Fig. 16, the waveform and switching loss of the output voltage correspond to (e) waveform example 5 (Fig. 8A and 8B), (i) waveform example 9 (Fig. 12A and Fig. 12B), and (j) waveform example from the left. 10 (Figures 13A and 13B).

(e) Waveform Example 5 shown in the left figure is an example of a waveform obtained by extending the first on-fixed period T1v and the second on-fixed period T2v. In other words, it is an example of a waveform in which V-phase is emphasized.

(i) Waveform example 9 shown in the center figure is a waveform example in which the first fixed ON period T1v, the first fixed ON period T1w, the second fixed ON period T2v, and the second fixed ON period T2w are equalized. That is, it is an example of a waveform in which portions other than the first fixed ON period T1u and the second fixed ON period T2u are equalized.

(j) Waveform example 10 shown in the figure on the right is a waveform example obtained by extending the first on-fixed period T1w and the second on-fixed period T2w. In other words, it is an example of a waveform in which the W phase is emphasized.

As the diagram shifts to the left, the first on-fixed period T1v and the second on-fixed period T2v become longer. Therefore, the switching loss of the V-phase first semiconductor switching element Vp (high side) and the V-phase second semiconductor switching element Vn (low side) decreases as the diagram shifts to the left.

On the other hand, the first on-fixed period T1w and the second on-fixed period T2w become longer as the graph shifts to the right. Therefore, the switching loss of the W-phase first semiconductor switching element Wp (high side) and the W-phase second semiconductor switching element Wn (low side) decreases as the diagram shifts to the right.

Next, the switching of the UH_UL guard waveform will be further described with reference to FIG. 19 . FIG. 19 is a graph showing switching loss.

As shown in Figure 19, in (f) Waveform Example 6 (Figure 9A), (h) Waveform Example 8 (Figure 11A), (k) Waveform Example 11 (Figure 14A) and (l) Waveform Example 12 (Figure 15A) Among them, the switching loss of the first semiconductor switching element Up (UH) and the switching loss of the second semiconductor switching element Un (UL) are 0.13.

In waveform example 6 (f), in addition to the first semiconductor switching element Up (UH) and the second semiconductor switching element Un (UL), the switching loss of the second semiconductor switching element Vn (VL) can be reduced to 0.57.

In waveform example 8 (h), in addition to the first semiconductor switching element Up (UH) and the second semiconductor switching element Un (UL), the switching loss of the first semiconductor switching element Wp (WH) can be reduced to 0.57.

In (k) waveform example 11, in addition to the first semiconductor switching element Up (UH) and the second semiconductor switching element Un (UL), the switching loss of the first semiconductor switching element Vp (VH) can be reduced to 0.57.

In (1) waveform example 12, in addition to the first semiconductor switching element Up (UH) and the second semiconductor switching element Un (UL), the switching loss of the second semiconductor switching element Wn (WL) can be reduced to 0.57.

The switching of the UH_UL protection waveform will be further described with reference to FIG. 20 . FIG. 20 is a diagram for explaining switching of UH_UL guard waveforms.

The waveform diagram shown in FIG. 20 corresponds to (i) waveform example 9 (FIG. 12A).

(a) Waveform example 1 ( FIG. 3A ) corresponds to a waveform obtained by extending the second on-fixed period T2 v and the second on-fixed period T2 w from (i) waveform example 9 . Therefore, the switching loss of the V-phase second semiconductor switching element Vn (VL) and the W-phase second semiconductor switching element Wn (WL) is reduced.

(c) Waveform example 3 ( FIG. 6A ) corresponds to a waveform obtained by extending the first on-fixed period T1v and the first on-fixed period T1w from (i) waveform example 9 . Therefore, the switching loss of the V-phase first semiconductor switching element Vp (VH) and the W-phase first semiconductor switching element Wp (WH) is reduced.

(e) Waveform Example 5 ( FIG. 8A ) corresponds to a waveform obtained by extending the first on-fixed period T1v and the second on-fixed period T2v from (i) waveform example 9 . Therefore, the switching loss of the V-phase first semiconductor switching element Vp (VH) and the V-phase second semiconductor switching element Vn (VL) is reduced.

(j) Waveform example 10 ( FIG. 13A ) corresponds to a waveform obtained by extending the first on-fixed period T1 w and the second on-fixed period T2 w from (i) waveform example 9 . Therefore, the switching loss of the W-phase first semiconductor switching element Wp (WH) and the W-phase second semiconductor switching element Wn (WL) is reduced.

(f) Waveform Example 6 ( FIG. 9A ) corresponds to a waveform obtained by extending the second on-fixed period T2 v from (i) Waveform Example 9 . Therefore, the switching loss of the V-phase second semiconductor switching element Vn(VL) is reduced.

(h) Waveform example 8 ( FIG. 11A ) corresponds to a waveform obtained by extending the first ON fixed period T1w from (i) Waveform example 9 . Therefore, the switching loss of the first semiconductor switching element Wp (WH) of the W phase is reduced.

(k) Waveform example 11 ( FIG. 14A ) corresponds to a waveform obtained by extending the first on-fixed period T1v from (i) Waveform example 9 . Therefore, the switching loss of the V-phase first semiconductor switching element Vp(VH) is reduced.

(1) Waveform Example 12 ( FIG. 15A ) corresponds to a waveform obtained by extending the second on-fixed period T2w from (i) Waveform Example 9 . Therefore, the switching loss of the W-phase second semiconductor switching element Wn (WL) is reduced.

A method of switching guard waveforms will be described with reference to FIG. 21 . FIG. 21 is a flowchart showing a method of switching guard waveforms.

Step S102: The signal generator 120 acquires the temperature T_UH, temperature T_UL, temperature T_VH, temperature T_VL, temperature T_WH, and temperature T_WL of each arm (semiconductor switching element). The temperature T_UH represents the temperature of the first semiconductor switching element Up. The temperature T_UL represents the temperature of the second semiconductor switching element Un. The temperature T_VH represents the temperature of the first semiconductor switching element Vp. The temperature T_VL represents the temperature of the second semiconductor switching element Vn. The temperature T_WH represents the temperature of the first semiconductor switching element Wp. The temperature T_WL represents the temperature of the second semiconductor switching element Wn.

Furthermore, the signal generator 120 sets the acquired temperatures T_UH, T_UL, T_VH, T_VL, T_WH, and T_WL as T_1, T_2, T_3, T_4, T_5, and T_6 in descending order of temperature. The process proceeds to step S104.

Step S104: The signal generator 120 judges whether the upper arm with the highest temperature (the first semiconductor switching element) and the lower arm with the highest temperature (the second semiconductor switching element) are in phase. When the signal generator 120 determines that the highest temperature upper arm (first semiconductor switching element) and the highest temperature lower arm (second semiconductor switching element) are not in phase (step S104 : NO), the process proceeds to step S108 . When the signal generator 120 determines that the highest temperature upper arm (first semiconductor switching element) and the highest temperature lower arm (second semiconductor switching element) are in phase (step S104 : Yes), the process proceeds to step S106 .

Step S106: The signal generator 120 modulates to suppress the temperature rise of the X-phase upper and lower layers. The X-phase is, for example, a U-phase, a V-phase, or a W-phase. Processing is complete. The detailed processing of step S106 will be described later with reference to FIGS. 22 to 24 .

Step S108: The signal generator 120 modulates to suppress the temperature rise of the X-phase upper layer and the Y-phase lower layer. The Y phase is, for example, a U phase, a V phase, or a W phase. Processing is complete. The detailed processing of step S108 will be described later with reference to FIGS. 47 to 49 .

The detailed processing of step S106 shown in FIG. 21 will be described with reference to FIGS. 22 to 24 . That is, the processing at the time of modulation to suppress the temperature rise of the X-phase upper and lower layers will be described. FIG. 22 is a flowchart showing a method of switching guard waveforms. 23 and 24 are diagrams showing a method of switching guard waveforms. In addition, FIGS. 22 to 24 show how to switch guard waveforms when the U phase is used as an example of the X phase.

Step S202: The signal generator 120 judges whether the temperatures T_3-T_6 are below the threshold T_Thr1. When the signal generator 120 determines that the temperatures T_3 to T_6 are not equal to or less than the threshold value T_Thr1 (step S202 : NO), the process proceeds to step S206 . When the signal generator 120 determines that the temperatures T_3 to T_6 are equal to or less than the threshold value T_Thr1 (step S202: Yes), the process proceeds to step S204.

Step S204: The signal generator 120 performs modulation in four protection modes. In detail, the signal generator 120 performs modulation with (i) waveform example 9. Processing is complete.

Step S206: The signal generator 120 judges whether the temperatures T_5-T_6 are below the threshold T_Thr2. When the signal generator 120 determines that the temperatures T_5 to T_6 are not equal to or less than the threshold value T_Thr2 (step S206 : NO), the process proceeds to step S210 . When the signal generator 120 determines that the temperatures T_5 to T_6 are equal to or less than the threshold value T_Thr2 (step S206: Yes), the process proceeds to step S208.

Step S208: The signal generator 120 performs modulation in the middle of the three protection modes and the four protection modes. Modulation between the three protection schemes and the four protection schemes will be described later with reference to FIG. 23 . Processing is complete.

Step S210: The signal generator 120 determines whether the temperatures T_3-T_5 are below the threshold T_Thr3. When the signal generator 120 determines that the temperatures T_3 to T_5 are not equal to or less than the threshold value T_Thr3 (step S210 : NO), the process proceeds to step S214 . When the signal generating unit 120 determines that the temperatures T_3 to T_5 are equal to or less than the threshold value T_Thr3 (step S210: Yes), the process proceeds to step S212.

Step S212: The signal generator 120 performs modulation in three protection modes. Specifically, the signal generator 120 can protect the arms (semiconductor Modulation by means of switching elements). Processing is complete.

Step S214: The signal generator 120 judges whether the temperatures T_4-T_5 are below the threshold T_Thr4. When the signal generator 120 determines that the temperatures T_4 to T_5 are not equal to or less than the threshold value T_Thr4 (step S214: NO), the process proceeds to step S218. When the signal generating unit 120 determines that the temperatures T_4 to T_5 are equal to or less than the threshold value T_Thr4 (step S214: Yes), the process proceeds to step S216.

Step S216: The signal generator 120 performs modulation in the middle of the two protection modes and the three protection modes. Modulation between the two protection schemes and the three protection schemes will be described later with reference to FIG. 24 . Processing is complete.

Step S218: The signal generator 120 performs modulation in two protection modes. In detail, the signal generator 120 can protect (a) waveform example 1, (c) waveform example 3, (e) waveform example 5, (f) waveform example 6, (i) waveform example 9, and (j) waveform example The temperature in 10 is modulated by means of arms (semiconductor switching elements) of T_3 and T_4. Processing is complete.

Next, the detailed processing of step S208 shown in FIG. 22 will be described with reference to FIG. 23 . That is, the processing when modulation is performed between the three protection schemes and the four protection schemes will be described.

The signal generation unit 120 determines the positions of the first three arms (semiconductor switching elements) with high temperatures other than UH (first semiconductor switching element Up) and UL (second semiconductor switching element Un). Hereinafter, in the description of FIG. 23 , the first three arms (semiconductor switching elements) with high temperatures other than “UH (first semiconductor switching element Up) and UL (second semiconductor switching element Un) are sometimes simply described as “ In addition, the temperature sequence of the first three arms is arbitrary. For example, the temperature sequence of the first three arms can be VH (the first semiconductor switching element Vp), VL (the second semiconductor switching element Vn) and The order of WH (first semiconductor switching element Wp) may also be the order of VH (first semiconductor switching element Vp), WH (first semiconductor switching element Wp) and VL (second semiconductor switching element Vn). Hereinafter, for In the same record, the order of the temperatures of the first three arms is also arbitrary.

When the signal generator 120 determines that the first three arms are VH (first semiconductor switching element Vp), VL (second semiconductor switching element Vn), and WH (first semiconductor switching element Wp), in (k) waveform example In 11, the signal generating unit 120 applies 150 degrees to 150+30×(T_Thr2-(T_5-T_6))/T_Thr2 degrees to the first on-fixed period, and applies 330 degrees to 330+30×(T_Thr2-(T_5-T_6)) /T_Thr2 degrees is applied to the second fixed-on period for modulation.

When the signal generating unit 120 determines that the first three arms are VH (first semiconductor switching element Vp), VL (second semiconductor switching element Vn), and WL (second semiconductor switching element Wn), the signal generating unit 120 uses ( f) Waveform example 6 for modulation.

When the signal generator 120 judges that the first three arms are VH (first semiconductor switching element Vp), VL (second semiconductor switching element Vn), and WH (first semiconductor switching element Wp), in (h) waveform example In 8, the signal generating unit 120 applies 0 degrees to 0+30×(T_Thr2−(T_5−T_6))/T_Thr2 degrees to the first on-fixed period, and applies 330 degrees to 330+30×(T_Thr2−(T_5−T_6)) /T_Thr2 is applied to the second fixed-on period for modulation.

When the signal generator 120 judges that the first three arms are VH (first semiconductor switching element Vp), VL (second semiconductor switching element Vn), and WL (second semiconductor switching element Wn), in (1) waveform example In 12, the signal generating unit 120 applies 180 degrees to 180+30×(T_Thr2-(T_5-T_6))/T_Thr2 degrees to the first on-fixed period, and applies 330 degrees to 330+30×(T_Thr2-(T_5-T_6)) /T_Thr2 degrees is applied to the second fixed-on period for modulation.

Next, detailed processing of step S216 shown in FIG. 22 will be described with reference to FIG. 24 . That is, the processing when modulation is performed between the two protection schemes and the three protection schemes will be described.

The signal generation unit 120 determines the positions of the two front arms (semiconductor switching elements) with high temperatures other than UH (first semiconductor switching element Up) and UL (second semiconductor switching element Un). Hereinafter, in the description of FIG. 24 , "the front two arms (semiconductor switching elements) with high temperatures other than UH (first semiconductor switching element Up) and UL (second semiconductor switching element Un)" may be simply described as "Front arms". In addition, the order of the temperatures of the first two arms is arbitrary. For example, the order of the temperatures of the first two arms may be the order of VL (the second semiconductor switching element Vn) and WL (the second semiconductor switching element Wn), or it may be the order of WL (the second semiconductor switching element Wn) and VL (the second semiconductor switching element Wn). Two semiconductor switching elements Vn) in sequence. Hereinafter, for the same description, the order of the temperatures of the first three arms is also arbitrary.

Furthermore, the signal generator 120 determines the position of the arm (semiconductor switching element) having the third highest temperature other than UH (first semiconductor switching element Up) and UL (second semiconductor switching element Un). Hereinafter, in the description of FIG. 24 , the arm (semiconductor switching element) with the third highest temperature other than UH (first semiconductor switching element Up) and UL (second semiconductor switching element Un) may be simply described as "The third warmest arm".

The signal generator 120 determines that the positions of the first two arms are VL (second semiconductor switching element Vn) and WL (second semiconductor switching element Vn), and the arm with the third highest temperature is VH (first semiconductor switching element Vp). In the case of (a) waveform example 1, the signal forming unit 120 modulates so that 180° to 180+30×(T_Thr4−(T_4−T_5))/T_Thr4° is applied to the first constant ON period. Processing is complete.

The signal generator 120 judges that the positions of the first two arms are VL (second semiconductor switching element Vn) and WL (second semiconductor switching element Vn), and the arm with the third highest temperature is WH (first semiconductor switching element Wp). In the case of (a) waveform example 1, the signal generation unit 120 modulates so that 330° to 330+30×(T_Thr4−(T_4−T_5))/T_Thr4° is applied to the first ON constant period. Processing is complete.

The signal generator 120 determines that the positions of the first two arms are VH (first semiconductor switching element Vp) and WH (first semiconductor switching element Wp), and the arm with the third highest temperature is VL (second semiconductor switching element Vn). In the case of (c) waveform example 3, the signal forming unit 120 modulates so that 0° to 0+30×(T_Thr4−(T_4−T_5))/T_Thr4° is applied to the second ON constant period.

The signal generator 120 determines that the positions of the first two arms are VH (first semiconductor switching element Vp) and WH (first semiconductor switching element Wp), and the arm with the third highest temperature is WL (second semiconductor switching element Wn). In the case of (c) waveform example 3, the signal forming unit 120 modulates so as to apply 150° to 150+30×(T_Thr4−(T_4−T_5))/T_Thr4° for the second on-fixed period.

The signal generator 120 determines that the positions of the first two arms are VH (first semiconductor switching element Vp) and VL (second semiconductor switching element Vn), and the arm with the third highest temperature is WH (first semiconductor switching element Wp). In the case of (e) waveform example 5, the signal forming unit 120 modulates so as to apply 330° to 330+30×(T_Thr4−(T_4−T_5))/T_Thr4° to the first constant ON period.

The signal generator 120 determines that the positions of the first two arms are VH (first semiconductor switching element Vp) and VL (second semiconductor switching element Vn), and the arm with the third highest temperature is WH (second semiconductor switching element Wn). In the case of (e) waveform example 5, the signal forming unit 120 modulates so that 150° to 150+30×(T_Thr4−(T_4−T_5))/T_Thr4° is applied to the second ON constant period.

The signal generator 120 determines that the positions of the first two arms are VH (first semiconductor switching element Vp) and WL (second semiconductor switching element Wn), and the arm with the third highest temperature is WH (first semiconductor switching element Wp). In the case of (f) waveform example 6, the signal forming unit 120 modulates so as to apply 330° to 330+60×(T_Thr4−(T_4−T_5))/T_Thr4° to the first constant ON period. However, when the upper limit exceeds 360 degrees D degrees, in (f) waveform example 6, the intervals to which the first ON fixed period is applied are 0 degrees to D degrees and 330 degrees to 360 degrees.

The signal generator 120 determines that the positions of the first two arms are VH (first semiconductor switching element Vp) and WL (second semiconductor switching element Wn), and the arm with the third highest temperature is VL (second semiconductor switching element Vn). In the case of , the signal forming unit 120 performs modulation with waveform example 6 (f). Processing is complete.

The signal generator 120 determines that the positions of the first two arms are VL (second semiconductor switching element Vn) and WH (first semiconductor switching element Wp), and the arm with the third highest temperature is WL (second semiconductor switching element Wn). In the case of (i) waveform example 9, the signal generation unit 120 modulates so that 180° to 180+30×(T_Thr4−(T_4−T_5))/T_Thr4° is applied to the second on-fixed period.

The signal generator 120 judges that the positions of the first two arms are VL (second semiconductor switching element Vn) and WH (first semiconductor switching element Wp), and the arm with the third highest temperature is VH (first semiconductor switching element Vp). In the case of (i) waveform example 9, the signal forming unit 120 modulates so that 150° to 150+30×(T_Thr4−(T_4−T_5))/T_Thr4° is applied to the first constant ON period.

The signal generator 120 determines that the positions of the first two arms are WH (first semiconductor switching element Wp) and WL (second semiconductor switching element Wn), and the arm with the third highest temperature is VL (second semiconductor switching element Vn). In the case of (j) waveform example 10, the signal generation unit 120 modulates so that 0° to 0+30×(T_Thr4−(T_4−T_5))/T_Thr4° is applied to the second ON constant period.

The signal generator 120 determines that the positions of the first two arms are WH (first semiconductor switching element Wp) and WL (second semiconductor switching element Wn), and the arm with the third highest temperature is VH (first semiconductor switching element Vp). In the case of (j) waveform example 10, the signal forming unit 120 modulates so as to apply 180° to 180+30×(T_Thr4−(T_4−T_5))/T_Thr4° to the first constant ON period.

As described above with reference to FIGS. 21 to 24 , the protection operation mode includes the first selection protection operation mode, and in the first selection protection operation mode, the first semiconductor switching element and the second semiconductor switching element of one phase are protected. , the first selective protection action mode includes a plurality of k protection action modes, and in the plurality of k protection action modes, for the first semiconductor switching element and the second semiconductor switching element of a phase other than one phase, k (k is a natural number below 2n-3) first semiconductor switching elements or second semiconductor switching elements for protection. The k protection action modes are selected based on the temperature information. Therefore, in the case where the temperature of a specific phase becomes a problem due to a problem of a cooling water channel, etc., by maximally suppressing the first semiconductor switching element and the second semiconductor switching element of a specific one phase At the same time, the temperature rise of other semiconductor switching elements required by the temperature conditions is also suppressed to improve the reliability of the inverter.

Waveform examples according to the embodiment of the present invention will be further described with reference to FIGS. 25 to 42B. FIG. 25 is a table showing the relationship between waveform examples and switching loss. In FIG. 25 , UH represents the switching loss of the U-phase first semiconductor switching element Up. UL represents the switching loss of the U-phase second semiconductor switching element Un. VH represents the switching loss of the V-phase first semiconductor switching element Vp. VL represents the switching loss of the V-phase second semiconductor switching element Vn. WH represents the switching loss of the first semiconductor switching element Wp of the W phase. WL represents the switching loss of the W-phase second semiconductor switching element Wn.

As shown in Fig. 25, in waveform example 13 to waveform example 29, UH is 0.32 and VL is 0.32, that is, in waveform example 13 to waveform example 29, the U-phase first semiconductor switching element Up and the V-phase second semiconductor An example of a waveform with little switching loss of the switching element Vn. That is, waveform examples 13 to 29 are waveform examples capable of protecting the U-phase first semiconductor switching element Up and the V-phase second semiconductor switching element Vn. In this specification, the waveforms that can protect the first semiconductor switching element (such as Up) of a certain phase (such as U phase) and the second semiconductor switching element (such as Vn) of another phase (such as V phase) are described as UH_VL protection waveform. The above waveform example corresponds to the case where the former first on-fixed period and the latter second on-fixed period are continuous.

Waveform Example 13 will be described with reference to FIGS. 26A and 26B . FIG. 26A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 26B is a graph showing switching loss.

As shown in Figure 26A, waveform example 13 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 13 is a waveform in which the output of any phase is fixed at 1 within an electrical angle of 60 degrees to 150 degrees. In addition, waveform example 13 is a waveform in which the output of any phase is fixed at 0 within an electrical angle of 0 degrees to an electrical angle of 60 degrees and an electrical angle of 150 degrees to 360 degrees. In waveform example 13, the high-side ON application period T3 is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In addition, in waveform example 13, the low-side ON application period T4 is the electrical angle of 0 degrees to the electrical angle of 60 degrees and the electrical angle of 150 degrees to the electrical angle of 360 degrees.

In waveform example 13, the first on-fixed period T1 includes the first on-fixed period T1u. In waveform example 13, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees.

In waveform example 13, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 13, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 13, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v. In waveform example 13, the second on-fixed period T2w is from an electrical angle of 150 degrees to an electrical angle of 210 degrees.

In waveform example 13, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 13, the first on-fixed period T1u is 120 degrees, whereas the first on-fixed period T1v and the first on-fixed period T1w are absent. That is, in waveform example 13, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 26B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 13, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 13, the second fixed ON period T2v is 90 degrees, whereas the second fixed ON period T2u is 120 degrees, and the second fixed ON period T2w is 60 degrees. That is, in waveform example 13, the second on-fixed period T2v is longer than the second on-fixed period T2w. Therefore, as shown in FIG. 26B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the W phase.

As described above with reference to FIGS. 26A and 26B , in the waveform example 13, similarly to the waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 13, the heat generation of the U-phase first semiconductor switching element Up and the V-phase second semiconductor switching element Vn can be simultaneously suppressed.

In addition, in waveform example 13, as shown in FIG. 26B , heat generation of the U-phase second semiconductor switching element Un and the W-phase second semiconductor switching element Wn can also be suppressed at the same time.

Waveform example 14 will be described with reference to FIGS. 27A and 27B . FIG. 27A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 27B is a graph showing switching loss.

As shown in Figure 27A, waveform example 14 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 14 is a waveform in which the output of any phase is fixed at 1 within the range of an electrical angle of 60 degrees to an electrical angle of 180 degrees. In addition, waveform example 14 is a waveform in which the output of any phase is fixed at 0 within an electrical angle of 0 degrees to an electrical angle of 60 degrees and an electrical angle of 180 degrees to 360 degrees. In waveform example 14, the high-side ON application period T3 is from an electrical angle of 60 degrees to an electrical angle of 180 degrees. In addition, in waveform example 14, the low-side ON application period T4 is the electrical angle of 0 degrees to the electrical angle of 60 degrees and the electrical angle of 180 degrees to the electrical angle of 360 degrees.

In waveform example 14, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1v. In waveform example 14, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In waveform example 14, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 180 degrees.

In waveform example 14, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 14, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 14, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v. In waveform example 14, the second on-fixed period T2w is from an electrical angle of 180 degrees to an electrical angle of 210 degrees.

In waveform example 14, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 14, the first on-fixed period T1u is 90 degrees, whereas the first on-fixed period T1v is 30 degrees and there is no first on-fixed period T1w. That is, in waveform example 14, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 27B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 14, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 14, the second fixed ON period T2v is 90 degrees, whereas the second fixed ON period T2u is 120 degrees, and the second fixed ON period T2w is 30 degrees. That is, in waveform example 14, the second on-fixed period T2v is longer than the second on-fixed period T2w. Therefore, as shown in FIG. 27B , the switching loss of the second semiconductor switching element Un (L (low side)) of the V phase is smaller than that of the W phase.

As described above with reference to FIGS. 27A and 27B , in waveform example 14, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 14, the heat generation of the first semiconductor switching element Up of the U-phase and the second semiconductor switching element Vn of the V-phase can be suppressed at the same time.

Furthermore, in waveform example 14, as shown in FIG. 27B , heat generation of the U-phase second semiconductor switching element Un, the V-phase first semiconductor switching element Vp, and the W-phase second semiconductor switching element Wn can also be suppressed simultaneously.

Waveform Example 15 will be described with reference to FIGS. 28A and 28B . FIG. 28A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 28B is a graph showing switching loss.

As shown in Figure 28A, waveform example 15 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 15 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 60 degrees to 210 degrees. In addition, waveform example 15 is a waveform in which the output of any phase is fixed at 0 within an electrical angle of 0 degrees to an electrical angle of 60 degrees and an electrical angle of 210 degrees to 360 degrees. In waveform example 15, the high-side ON application period T3 is from an electrical angle of 60 degrees to an electrical angle of 210 degrees. In addition, in waveform example 15, the low-side ON application period T4 is the electrical angle of 0 degrees to the electrical angle of 60 degrees and the electrical angle of 210 degrees to the electrical angle of 360 degrees.

In waveform example 15, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1v. In waveform example 15, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In waveform example 15, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 210 degrees.

In waveform example 15, the second on-fixed period T2 includes a second on-fixed period T2u and a second on-fixed period T2v. In waveform example 15, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 15, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v.

In waveform example 15, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. In detail, in waveform example 15, the first on-fixed period T1u is 90 degrees, whereas the first on-fixed period T1v is 60 degrees, and there is no first on-fixed period T1w. That is, in waveform example 15, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 28B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 15, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 15, the second fixed ON period T2v is 90 degrees, whereas the second fixed ON period T2u is 120 degrees, and there is no second fixed ON period T2w. That is, in waveform example 15, the second on-fixed period T2v is longer than the second on-fixed period T2w. Therefore, as shown in FIG. 28B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the W phase.

As described above with reference to FIGS. 28A and 28B , in waveform example 15, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 15, the heat generation of the U-phase first semiconductor switching element Up and the V-phase second semiconductor switching element Vn can be simultaneously suppressed.

In addition, in waveform example 15, as shown in FIG. 28B , heat generation of the U-phase second semiconductor switching element Un and the V-phase first semiconductor switching element Vp can be simultaneously suppressed.

Waveform Example 16 will be described with reference to FIGS. 29A and 29B . FIG. 29A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 29B is a graph showing switching loss.

As shown in Figure 29A, waveform example 16 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 16 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 60 degrees to 240 degrees. In addition, waveform example 16 is a waveform in which the output of any phase is fixed at 0 within an electrical angle of 0 degrees to an electrical angle of 60 degrees and an electrical angle of 240 degrees to 360 degrees. In waveform example 16, the high-side ON application period T3 is from an electrical angle of 60 degrees to an electrical angle of 240 degrees. In addition, in the waveform example 16, the low-side ON application period T4 is the electrical angle of 0 degrees to the electrical angle of 60 degrees and the electrical angle of 240 degrees to the electrical angle of 360 degrees.

In waveform example 16, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1v. In waveform example 16, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In waveform example 16, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 240 degrees.

In waveform example 16, the second on-fixed period T2 includes a second on-fixed period T2u and a second on-fixed period T2v. In waveform example 16, the second on-fixed period T2u is from an electrical angle of 240 degrees to an electrical angle of 330 degrees. In waveform example 16, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v.

In waveform example 16, in the U phase among the three phases, the first on-fixed period T1u is different from the first on-fixed period T1w. In detail, in waveform example 16, the first on-fixed period T1u is 90 degrees, but there is no first on-fixed period T1w. That is, in waveform example 16, the first on-fixed period T1u is longer than the first on-fixed period T1w. In addition, in waveform example 16, the first on-fixed period T1u is equal to the first on-fixed period T1v. Therefore, as shown in FIG. 29B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the W phase.

In waveform example 16, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. In detail, in waveform example 16, the second on-fixed period T2v is 90 degrees, whereas there is no second on-fixed period T2w. That is, in waveform example 16, the second on-fixed period T2v is longer than the second on-fixed period T2w. In addition, in waveform example 16, the second on-fixed period T2u is equal to the second on-fixed period T2v. Therefore, as shown in FIG. 29B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the W phase.

As described above with reference to FIGS. 29A and 29B , in the waveform example 16, similarly to the waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 16, the heat generation of the first semiconductor switching element Up of the U-phase and the second semiconductor switching element Vn of the V-phase can be suppressed at the same time.

In addition, in waveform example 16, as shown in FIG. 29B , heat generation of the U-phase second semiconductor switching element Un and the V-phase first semiconductor switching element Vp can be simultaneously suppressed.

Waveform example 17 will be described with reference to FIGS. 30A and 30B . FIG. 30A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 30B is a graph showing switching loss.

As shown in Figure 30A, waveform example 17 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 17 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 60 degrees to 270 degrees. In addition, waveform example 17 is a waveform in which the output of any phase is fixed at 0 within an electrical angle of 0° to 60° and an electrical angle of 270° to 360°. In waveform example 17, the high-side ON application period T3 is from an electrical angle of 60 degrees to an electrical angle of 270 degrees. In addition, in waveform example 17, the low-side ON application period T4 is the electrical angle of 0 degrees to the electrical angle of 60 degrees and the electrical angle of 270 degrees to the electrical angle of 360 degrees.

In waveform example 17, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1v. In waveform example 17, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In waveform example 17, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 270 degrees.

In waveform example 17, the second on-fixed period T2 includes a second on-fixed period T2u and a second on-fixed period T2v. In waveform example 17, the second on-fixed period T2u is from an electrical angle of 270 degrees to an electrical angle of 330 degrees. In waveform example 17, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v.

In waveform example 17, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 17, the first on-fixed period T1u is 90 degrees, whereas the first on-fixed period T1v is 120 degrees, and there is no first on-fixed period T1w. That is, in waveform example 17, the first on-fixed period T1u is longer than the first on-fixed period T1w. Therefore, as shown in FIG. 30B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the W phase.

In waveform example 17, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 17, the second fixed ON period T2v is 90 degrees, whereas the second fixed ON period T2u is 60 degrees, and there is no second fixed ON period T2w. That is, in waveform example 17, the second on-fixed period T2v is longer than the second on-fixed period T2u and the second on-fixed period T2w. Therefore, as shown in FIG. 30B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the U phase and the W phase.

As described above with reference to FIGS. 30A and 30B , in waveform example 17, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 17, the heat generation of the U-phase first semiconductor switching element Up and the V-phase second semiconductor switching element Vn can be simultaneously suppressed.

In addition, in waveform example 17, as shown in FIG. 30B , heat generation of the U-phase second semiconductor switching element Un and the V-phase first semiconductor switching element Vp can be simultaneously suppressed.

Waveform example 18 will be described with reference to FIGS. 31A and 31B . FIG. 31A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 31B is a graph showing switching loss.

As shown in Figure 31A, waveform example 18 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 18 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 60 degrees to 300 degrees. In addition, waveform example 18 is a waveform in which the output of any phase is fixed at 0 within an electrical angle of 0 degrees to an electrical angle of 60 degrees and an electrical angle of 300 degrees to an electrical angle of 360 degrees. In waveform example 18, the high-side ON application period T3 is from an electrical angle of 60 degrees to an electrical angle of 300 degrees. In addition, in the waveform example 18, the low-side ON application period T4 is the electrical angle of 0 degrees to the electrical angle of 60 degrees and the electrical angle of 300 degrees to the electrical angle of 360 degrees.

In waveform example 18, the first on-fixed period T1 includes the first on-fixed period T1u. In waveform example 18, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In waveform example 18, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 270 degrees. In waveform example 18, the first on-fixed period T1w is from an electrical angle of 270 degrees to an electrical angle of 300 degrees.

In waveform example 18, the second on-fixed period T2 includes a second on-fixed period T2u and a second on-fixed period T2v. In waveform example 18, the second on-fixed period T2u is from an electrical angle of 300 degrees to an electrical angle of 330 degrees. In waveform example 18, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v.

In waveform example 18, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 18, the first on-fixed period T1u is 90 degrees, whereas the first on-fixed period T1v is 120 degrees, and the first on-fixed period T1w is 30 degrees. That is, in waveform example 18, the first on-fixed period T1u is longer than the first on-fixed period T1w. Therefore, as shown in FIG. 31B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the W phase.

In waveform example 18, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 18, the second fixed ON period T2v is 90 degrees, whereas the second fixed ON period T2u is 30 degrees, and there is no second fixed ON period T2w. That is, in waveform example 18, the second on-fixed period T2v is longer than the second on-fixed period T2u and the second on-fixed period T2w. Therefore, as shown in FIG. 31B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the U phase and the W phase.

As described above with reference to FIG. 31A and FIG. 31B , in waveform example 18, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 18, the heat generation of the first semiconductor switching element Up of the U-phase and the second semiconductor switching element Vn of the V-phase can be suppressed at the same time.

In addition, in waveform example 18, as shown in FIG. 31B , heat generation of the U-phase second semiconductor switching element Un, the V-phase first semiconductor switching element Vp, and the W-phase first semiconductor switching element Wp can be simultaneously suppressed.

Waveform example 19 will be described with reference to FIGS. 32A and 32B . FIG. 32A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 32B is a graph showing switching loss.

As shown in Figure 32A, waveform example 19 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 19 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 60 degrees to an electrical angle of 330 degrees. In addition, waveform example 19 is a waveform in which the output of any phase is fixed at 0 within an electrical angle of 0° to an electrical angle of 60° and an electrical angle of 330° to 360°. In waveform example 19, the high-side ON application period T3 is from an electrical angle of 60 degrees to an electrical angle of 330 degrees. In addition, in waveform example 19, the low-side ON application period T4 is the electrical angle of 0° to 60° and the electrical angle of 330° to 360°.

In waveform example 19, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 19, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In waveform example 19, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 270 degrees. In waveform example 19, the first on-fixed period T1w is from an electrical angle of 270 degrees to an electrical angle of 330 degrees.

In waveform example 19, the second on-fixed period T2 includes a second on-fixed period T2v. In waveform example 19, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v.

In waveform example 19, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 19, the first on-fixed period T1u is 90 degrees, whereas the first on-fixed period T1v is 120 degrees, and the first on-fixed period T1w is 60 degrees. That is, in waveform example 19, the first on-fixed period T1u is longer than the first on-fixed period T1w. Therefore, as shown in FIG. 32B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the W phase.

In waveform example 19, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 19, the second on-fixed period T2v is 90 degrees, whereas the second on-fixed period T2u and the second on-fixed period T2w are absent. That is, in waveform example 19, the second on-fixed period T2v is longer than the second on-fixed period T2u and the second on-fixed period T2w. Therefore, as shown in FIG. 32B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the U phase and the W phase.

As described above with reference to FIGS. 32A and 32B , in waveform example 19, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 19, the heat generation of the first semiconductor switching element Up of the U-phase and the second semiconductor switching element Vn of the V-phase can be suppressed at the same time.

In addition, in waveform example 19, as shown in FIG. 32B , heat generation of the V-phase first semiconductor switching element Vp and the W-phase first semiconductor switching element Wp can also be suppressed at the same time.

Waveform example 20 will be described with reference to FIGS. 33A and 33B . FIG. 33A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 33B is a graph showing switching loss.

As shown in FIG. 33A, waveform example 20 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0. . In detail, waveform example 20 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 60° to 150° and an electrical angle of 300° to 330°. In addition, the waveform example 20 is a waveform as follows, that is, within an electrical angle of 0 degrees to an electrical angle of 60 degrees, an electrical angle of 150 degrees to an electrical angle of 300 degrees, and an electrical angle of 330 degrees to an electrical angle of 360 degrees, any The phase output is fixed at 0. In waveform example 20, the high-side ON application period T3 is an electrical angle of 60° to an electrical angle of 150° and an electrical angle of 300° to an electrical angle of 330°. In addition, in waveform example 20, the electrical angle of 0 degrees to 60 degrees, the electrical angle of 150 degrees to 300 degrees, and the electrical angle of 330 degrees to 360 degrees are low-side ON application periods. T4.

In waveform example 20, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1w. In waveform example 20, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In waveform example 20, the first on-fixed period T1w is from an electrical angle of 300 degrees to an electrical angle of 330 degrees.

In waveform example 20, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 20, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 300 degrees. In the waveform example 20, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v. In waveform example 20, the second on-fixed period T2w is from an electrical angle of 150 degrees to an electrical angle of 210 degrees.

In waveform example 20, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 20, the first on-fixed period T1u is 90 degrees, whereas the first on-fixed period T1v is absent and the first on-fixed period T1w is 30 degrees. That is, in waveform example 20, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 33B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 20, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 20, the second fixed ON period T2v is 90 degrees, whereas the second fixed ON period T2u is 90 degrees, and the second fixed ON period T2w is 60 degrees. That is, in waveform example 20, the second on-fixed period T2v is longer than the second on-fixed period T2w. Therefore, as shown in FIG. 33B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the W phase.

As described above with reference to FIGS. 33A and 33B , in waveform example 20, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 20, the heat generation of the U-phase first semiconductor switching element Up and the V-phase second semiconductor switching element Vn can be simultaneously suppressed.

In addition, in waveform example 20, as shown in FIG. 33B , heat generation of the U-phase second semiconductor switching element Un, the W-phase first semiconductor switching element Wp, and the W-phase second semiconductor switching element Wn can also be suppressed simultaneously.

Waveform example 21 will be described with reference to FIGS. 34A and 34B . FIG. 34A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 34B is a graph showing switching loss.

As shown in Fig. 34A, waveform example 21 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 21 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 60 degrees to 150 degrees and an electrical angle of 270 degrees to 330 degrees. In addition, Waveform Example 21 is a waveform in which any of the electrical angles from 0° to 60° in electrical angle, 150° in electrical angle to 270° in electrical angle, and 330° in electrical angle to 360° in electrical angle The phase output is fixed at 0. In waveform example 21, the high-side ON application period T3 is an electrical angle of 60 degrees to an electrical angle of 150 degrees and an electrical angle of 270 degrees to an electrical angle of 330 degrees. In addition, in waveform example 21, the electrical angle of 0° to 60°, the electrical angle of 150° to 270°, and the electrical angle of 330° to 360° are low-side ON application periods. T4.

In waveform example 21, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1w. In waveform example 21, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In waveform example 21, the first on-fixed period T1w is from an electrical angle of 270 degrees to an electrical angle of 330 degrees.

In waveform example 21, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 21, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 270 degrees. In waveform example 21, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v. In waveform example 21, the second on-fixed period T2w is from an electrical angle of 150 degrees to an electrical angle of 210 degrees.

In waveform example 21, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 21, the first on-fixed period T1u is 90 degrees, whereas the first on-fixed period T1v is absent and the first on-fixed period T1w is 60 degrees. That is, in waveform example 21, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 34B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 21, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 21, the second fixed ON period T2v is 90 degrees, whereas the second fixed ON period T2u is 60 degrees, and the second fixed ON period T2w is 60 degrees. That is, in waveform example 21, the second on-fixed period T2v is longer than the second on-fixed period T2u and the second on-fixed period T2w. Therefore, as shown in FIG. 34B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the U phase and the W phase.

As described above with reference to FIGS. 34A and 34B , in waveform example 21, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In the waveform example 21, heat generation of the U-phase first semiconductor switching element Up and the V-phase second semiconductor switching element Vn can be simultaneously suppressed.

In addition, in waveform example 21, as shown in FIG. 34B , heat generation of the U-phase second semiconductor switching element Un, the W-phase first semiconductor switching element Wp, and the W-phase second semiconductor switching element Wn can also be suppressed simultaneously.

Waveform example 22 will be described with reference to FIGS. 35A and 35B . FIG. 35A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 35B is a graph showing switching loss.

As shown in FIG. 35A, waveform example 22 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 22 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 60° to 150° and an electrical angle of 240° to 330°. In addition, waveform example 22 is a waveform such that any electrical angle is within an electrical angle of 0 degrees to an electrical angle of 60 degrees, an electrical angle of 150 degrees to an electrical angle of 240 degrees, and an electrical angle of 330 degrees to an electrical angle of 360 degrees. The phase output is fixed at 0. In waveform example 22, the high-side ON application period T3 is an electrical angle of 60 degrees to an electrical angle of 150 degrees and an electrical angle of 240 degrees to an electrical angle of 330 degrees. In addition, in waveform example 22, the electrical angle of 0° to 60°, the electrical angle of 150° to 240°, and the electrical angle of 330° to 360° are low-side ON application periods. T4.

In waveform example 22, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 22, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In waveform example 22, an electrical angle of 240° to an electrical angle of 270° is the first on-fixed period T1v. In waveform example 22, the first on-fixed period T1w is from an electrical angle of 270 degrees to an electrical angle of 330 degrees.

In waveform example 22, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 22, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 240 degrees. In the waveform example 22, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v. In waveform example 22, the second on-fixed period T2w is from an electrical angle of 150 degrees to an electrical angle of 210 degrees.

In waveform example 22, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 22, the first on-fixed period T1u is 90 degrees, while the first on-fixed period T1v is 30 degrees, and the first on-fixed period T1w is 60 degrees. That is, in waveform example 22, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 35B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 22, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 22, the second fixed ON period T2v is 90 degrees, whereas the second fixed ON period T2u is 30 degrees, and the second fixed ON period T2w is 60 degrees. That is, in waveform example 22, the second on-fixed period T2v is longer than the second on-fixed period T2u and the second on-fixed period T2w. Therefore, as shown in FIG. 35B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the U phase and the W phase.

As described above with reference to FIGS. 35A and 35B , in waveform example 22, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 22, the heat generation of the U-phase first semiconductor switching element Up and the V-phase second semiconductor switching element Vn can be simultaneously suppressed.

In addition, in waveform example 22, as shown in FIG. 35B , the U-phase second semiconductor switching element Un, the V-phase first semiconductor switching element Vp, the W-phase first semiconductor switching element Wp, and the W-phase The heat generation of the second semiconductor switching element Wn.

Waveform example 23 will be described with reference to FIGS. 36A and 36B . FIG. 36A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 36B is a graph showing switching loss.

As shown in Figure 36A, waveform example 23 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 23 is a waveform in which the output of any phase is fixed at 1 within an electrical angle of 60° to 150° and an electrical angle of 210° to 330°. In addition, waveform example 23 is a waveform such that any electrical angle is within the electrical angle of 0° to 60°, the electrical angle of 150° to 210°, and the electrical angle of 330° to 360°. The phase output is fixed at 0. In waveform example 23, the high-side ON application period T3 is an electrical angle of 60 degrees to an electrical angle of 150 degrees and an electrical angle of 210 degrees to an electrical angle of 330 degrees. In addition, in waveform example 23, the electrical angle of 0° to 60°, the electrical angle of 150° to 210°, and the electrical angle of 330° to 360° are low-side ON application periods. T4.

In waveform example 23, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 23, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In waveform example 23, an electrical angle of 210 degrees to an electrical angle of 270 degrees is the first on-fixed period T1v. In waveform example 23, the first on-fixed period T1u is from an electrical angle of 270 degrees to an electrical angle of 330 degrees.

In waveform example 23, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 23, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v. In waveform example 23, the second on-fixed period T2w is from an electrical angle of 150 degrees to an electrical angle of 210 degrees.

In waveform example 23, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 23, the first on-fixed period T1u is 90 degrees, whereas the first on-fixed period T1v and the first on-fixed period T1w are 60 degrees. That is, in waveform example 23, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 36B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 23, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 23, the second on-fixed period T2v is 90 degrees, whereas the second on-fixed period T2u is absent, and the second on-fixed period T2w is 60 degrees. That is, in waveform example 23, the second on-fixed period T2v is longer than the second on-fixed period T2w. Therefore, as shown in FIG. 36B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the U phase and the W phase.

As described above with reference to FIGS. 36A and 36B , in waveform example 23, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 23, the heat generation of the U-phase first semiconductor switching element Up and the V-phase second semiconductor switching element Vn can be simultaneously suppressed.

In addition, in waveform example 23, as shown in FIG. 36B , heat generation of the V-phase first semiconductor switching element Vp, the W-phase first semiconductor switching element Wp, and the W-phase second semiconductor switching element Wn can be simultaneously suppressed.

Waveform example 24 will be described with reference to FIGS. 37A and 37B . FIG. 37A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 37B is a graph showing switching loss.

As shown in FIG. 37A, waveform example 24 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 24 is a waveform in which the output of any phase is fixed at 1 within an electrical angle of 60° to 150° and an electrical angle of 180° to 330°. In addition, the waveform example 24 is a waveform such that any electrical angle is within an electrical angle of 0° to 60°, an electrical angle of 150° to 180°, and an electrical angle of 330° to 360°. The phase output is fixed at 0. In waveform example 24, the high-side ON application period T3 is the electrical angle of 60 degrees to the electrical angle of 150 degrees and the electrical angle of 180 degrees to the electrical angle of 330 degrees. In addition, in waveform example 24, the electrical angle of 0 degrees to 60 degrees, the electrical angle of 150 degrees to 180 degrees, and the electrical angle of 330 degrees to 360 degrees are low-side ON application periods. T4.

In waveform example 24, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 24, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In waveform example 24, the electrical angle of 180° to 270° is the first on-fixed period T1v. In waveform example 24, the first on-fixed period T1w is from an electrical angle of 270 degrees to an electrical angle of 330 degrees.

In waveform example 24, the second on-fixed period T2 includes a second on-fixed period T2v and a second on-fixed period T2w. In the waveform example 24, the electrical angle of 0 degrees to the electrical angle of 60 degrees and the electrical angle of 330 degrees to the electrical angle of 360 degrees are the second on-fixed period T2v. In the waveform example 24, the second on-fixed period T2w is from an electrical angle of 150 degrees to an electrical angle of 180 degrees.

In waveform example 24, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1w. Specifically, in waveform example 24, the first on-fixed period T1u is 90 degrees, whereas the first on-fixed period T1w is 60 degrees. That is, in waveform example 24, the first on-fixed period T1u is longer than the first on-fixed period T1w. In addition, the first on-fixed period T1u is the same as the first on-fixed period T1v. Therefore, as shown in FIG. 37B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the W phase.

In waveform example 24, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 24, the second on-fixed period T2v is 90 degrees, whereas the second on-fixed period T2w is 30 degrees. That is, in waveform example 24, the second on-fixed period T2v is longer than the second on-fixed period T2w. Therefore, as shown in FIG. 37B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the W phase.

As described above with reference to FIGS. 37A and 37B , in waveform example 24, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In the waveform example 24, heat generation of the U-phase first semiconductor switching element Up and the V-phase second semiconductor switching element Vn can be simultaneously suppressed.

In addition, in waveform example 24, as shown in FIG. 37B , heat generation of the V-phase first semiconductor switching element Vp, the W-phase first semiconductor switching element Wp, and the W-phase second semiconductor switching element Wn can be simultaneously suppressed.

Waveform Example 25 will be described with reference to FIGS. 38A and 38B . FIG. 38A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 38B is a graph showing switching loss.

As shown in Figure 38A, waveform example 25 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 25 has the following waveforms, that is, within the electrical angle of 60 degrees to 150 degrees, the electrical angle of 210 degrees to 240 degrees, and the electrical angle of 270 degrees to 330 degrees, any The output of one phase is fixed at 1. In addition, the waveform example 25 is a waveform such that the electrical angle is 0° to 60°, the electrical angle is 150° to 210°, the electrical angle is 240° to 270°, and the electrical angle is 270°. The output of any phase is fixed at 0 within the electrical angle of 330 degrees to 360 degrees. In waveform example 25, the high-side ON application period T3 is the electrical angle from 60° to 150°, the electrical angle from 210° to 240°, and the electrical angle from 270° to 330°. In addition, in waveform example 25, the electrical angle ranges from 0° to 60°, the electrical angle ranges from 150° to 210°, the electrical angle ranges from 240° to 270°, and the electrical angle ranges from 330° to An electrical angle of 360 degrees is the low side on application period T4.

In waveform example 25, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 25, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In waveform example 25, the electrical angle of 210° to 240° is the first on-fixed period T1v. In waveform example 25, the first on-fixed period T1w is from an electrical angle of 270 degrees to an electrical angle of 330 degrees.

In waveform example 25, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 25, the second on-fixed period T2u is from an electrical angle of 240 degrees to an electrical angle of 270 degrees. In waveform example 25, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v. In waveform example 25, the second on-fixed period T2w is from an electrical angle of 150 degrees to an electrical angle of 210 degrees.

In waveform example 25, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 25, the first on-fixed period T1u is 90 degrees, whereas the first on-fixed period T1v is 30 degrees, and the first on-fixed period T1w is 60 degrees. That is, in waveform example 25, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 38B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 25, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 25, the second fixed ON period T2v is 90 degrees, whereas the second fixed ON period T2u is 30 degrees, and the second fixed ON period T2w is 60 degrees. That is, in waveform example 25, the second on-fixed period T2v is longer than the second on-fixed period T2u and the second on-fixed period T2w. Therefore, as shown in FIG. 38B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the U phase and the W phase.

As described above with reference to FIGS. 38A and 38B , in waveform example 25, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 25, the heat generation of the U-phase first semiconductor switching element Up and the V-phase second semiconductor switching element Vn can be simultaneously suppressed.

In addition, in waveform example 25, as shown in FIG. 38B , the U-phase second semiconductor switching element Un, the V-phase first semiconductor switching element Vp, the W-phase first semiconductor switching element Wp, and the W-phase The heat generation of the second semiconductor switching element Wn.

Waveform example 26 will be described with reference to FIGS. 39A and 39B . FIG. 39A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 39B is a graph showing switching loss.

As shown in FIG. 39A, waveform example 26 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, the waveform example 26 has the following waveforms, that is, within the electrical angle of 60 degrees to 150 degrees, the electrical angle of 195 degrees to 240 degrees, and the electrical angle of 285 degrees to 330 degrees, any The output of one phase is fixed at 1. In addition, waveform example 26 is a waveform such that the electrical angle is 0° to 60°, the electrical angle is 150° to 195°, the electrical angle is 240° to 285°, and the electrical angle is 285°. The output of any phase is fixed at 0 within the electrical angle of 330 degrees to 360 degrees. In waveform example 26, the high-side ON application period T3 is the electrical angle of 60° to 150°, the electrical angle of 195° to 240°, and the electrical angle of 285° to 330°. In addition, in waveform example 26, the electrical angle ranges from 0° to 60°, the electrical angle ranges from 150° to 195°, the electrical angle ranges from 240° to 285°, and the electrical angle ranges from 330° to An electrical angle of 360 degrees is the low side on application period T4.

In waveform example 26, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 26, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In waveform example 26, the first on-fixed period T1v is from an electrical angle of 195 degrees to an electrical angle of 240 degrees. In waveform example 26, the first on-fixed period T1w is from an electrical angle of 285 degrees to an electrical angle of 330 degrees.

In waveform example 26, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 26, the second on-fixed period T2u is from an electrical angle of 240 degrees to an electrical angle of 285 degrees. In waveform example 26, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v. In waveform example 26, the electrical angle of 150° to 195° is the second on-fixed period T2w.

In waveform example 26, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 26, the first on-fixed period T1u is 90 degrees, whereas the first on-fixed period T1v and the first on-fixed period T1w are 45 degrees. That is, in waveform example 26, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 39B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 26, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 26, the second on-fixed period T2v is 90 degrees, whereas the second on-fixed period T2u and the second on-fixed period T2w are 45 degrees. That is, in waveform example 26, the second on-fixed period T2v is longer than the second on-fixed period T2u and the second on-fixed period T2w. Therefore, as shown in FIG. 39B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the U phase and the W phase.

As described above with reference to FIGS. 39A and 39B , in waveform example 26, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 26, the heat generation of the U-phase first semiconductor switching element Up and the V-phase second semiconductor switching element Vn can be simultaneously suppressed.

In addition, in waveform example 26, as shown in FIG. 39B, the second semiconductor switching element Un of the U phase, the first semiconductor switching element Vp of the V phase, the first semiconductor switching element Wp of the W phase, and the W phase The heat generation of the second semiconductor switching element Wn.

Waveform example 27 will be described with reference to FIGS. 40A and 40B . FIG. 40A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 40B is a graph showing switching loss.

As shown in Figure 40A, waveform example 27 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 27 has the following waveforms, that is, within the electrical angle of 60 degrees to 150 degrees, the electrical angle of 180 degrees to 240 degrees, and the electrical angle of 300 degrees to 330 degrees, any The output of one phase is fixed at 1. In addition, the waveform example 27 has the following waveforms, that is, when the electrical angle is 0 degrees to 60 degrees, the electrical angle is 150 degrees to 180 degrees, the electrical angle is 240 degrees to 300 degrees, and the electrical angle is The output of any phase is fixed at 0 within the electrical angle of 330 degrees to 360 degrees. In waveform example 27, the high-side ON application period T3 is the electrical angle of 60° to 150°, the electrical angle of 180° to 240°, and the electrical angle of 300° to 330°. In addition, in waveform example 27, the electrical angle is 0 to 60 degrees, the electrical angle is 150 to 180 degrees, the electrical angle is 240 to 300 degrees, and the electrical angle is 330 to 330 degrees. An electrical angle of 360 degrees is the low side on application period T4.

In waveform example 27, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 27, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In waveform example 27, the first on-fixed period T1v is from an electrical angle of 180 degrees to an electrical angle of 240 degrees. In waveform example 27, an electrical angle of 300 degrees to an electrical angle of 330 degrees is the first on-fixed period T1w.

In waveform example 27, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 27, the second on-fixed period T2u is from an electrical angle of 240 degrees to an electrical angle of 300 degrees. In waveform example 27, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v. In waveform example 27, the second on-fixed period T2w is from an electrical angle of 150 degrees to an electrical angle of 180 degrees.

In waveform example 27, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 27, the first on-fixed period T1u is 90 degrees, while the first on-fixed period T1v is 60 degrees, and the first on-fixed period T1w is 30 degrees. That is, in waveform example 27, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 40B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 27, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 27, the second fixed ON period T2v is 90 degrees, whereas the second fixed ON period T2u is 60 degrees, and the second fixed ON period T2w is 30 degrees. That is, in waveform example 27, the second on-fixed period T2v is longer than the second on-fixed period T2u and the second on-fixed period T2w. Therefore, as shown in FIG. 40B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the U phase and the W phase.

As described above with reference to FIGS. 40A and 40B , in waveform example 27, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 27, the heat generation of the first semiconductor switching element Up of the U-phase and the second semiconductor switching element Vn of the V-phase can be suppressed at the same time.

In addition, in waveform example 27, as shown in FIG. 40B , the U-phase second semiconductor switching element Un, the V-phase first semiconductor switching element Vp, the W-phase first semiconductor switching element Wp, and the W-phase The heat generation of the second semiconductor switching element Wn.

Waveform example 28 will be described with reference to FIGS. 41A and 41B . FIG. 41A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 41B is a graph showing switching loss.

As shown in Figure 41A, waveform example 28 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 28 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 60° to 150° and an electrical angle of 210° to 270°. In addition, the waveform example 28 is a waveform such that any electrical angle is within an electrical angle of 0° to 60°, an electrical angle of 150° to 210°, and an electrical angle of 270° to 360°. The phase output is fixed at 0. In waveform example 28, the high-side ON application period T3 is an electrical angle of 60 degrees to an electrical angle of 150 degrees and an electrical angle of 210 degrees to an electrical angle of 270 degrees. In addition, in waveform example 28, the electrical angle of 0 degrees to 60 degrees, the electrical angle of 150 degrees to 210 degrees, and the electrical angle of 270 degrees to 360 degrees are low-side ON application periods. T4.

In waveform example 28, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1v. In waveform example 28, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In waveform example 28, the first on-fixed period T1v is from an electrical angle of 210 degrees to an electrical angle of 270 degrees.

In waveform example 28, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 28, the second on-fixed period T2u is from an electrical angle of 270 degrees to an electrical angle of 330 degrees. In waveform example 28, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v. In waveform example 28, the second on-fixed period T2w is from an electrical angle of 150 degrees to an electrical angle of 210 degrees.

In waveform example 28, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. In detail, in waveform example 28, the first on-fixed period T1u is 90 degrees, whereas the first on-fixed period T1v is 60 degrees, and there is no first on-fixed period T1w. That is, in waveform example 28, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 41B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 28, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 28, the second on-fixed period T2v is 90 degrees, whereas the second on-fixed period T2u and the second on-fixed period T2w are 60 degrees. That is, in waveform example 28, the second on-fixed period T2v is longer than the second on-fixed period T2u and the second on-fixed period T2w. Therefore, as shown in FIG. 41B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the U phase and the W phase.

As described above with reference to FIGS. 41A and 41B , in waveform example 28, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 28, heat generation of the first semiconductor switching element Up of the U-phase and the second semiconductor switching element Vn of the V-phase can be suppressed at the same time.

In addition, in waveform example 28, as shown in FIG. 41B , heat generation of the U-phase second semiconductor switching element Un, the V-phase first semiconductor switching element Vp, and the W-phase second semiconductor switching element Wn can be simultaneously suppressed.

Waveform example 29 will be described with reference to FIGS. 42A and 42B . FIG. 42A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 42B is a graph showing switching loss.

As shown in FIG. 42A, waveform example 29 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 29 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 60° to 210° and an electrical angle of 270° to 330°. In addition, waveform example 29 is a waveform in which any of the electrical angles from 0° to 60°, from 210° to 270°, and from 330° to 360° are The phase output is fixed at 0. In waveform example 29, the high-side-on application period T3 is an electrical angle of 60 degrees to an electrical angle of 210 degrees and an electrical angle of 270 degrees to an electrical angle of 330 degrees. In addition, in waveform example 29, the electrical angle of 0 degrees to 60 degrees, the electrical angle of 210 degrees to 270 degrees, and the electrical angle of 330 degrees to 360 degrees are low-side ON application periods. T4.

In waveform example 29, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 29, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 150 degrees. In waveform example 29, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 210 degrees. In waveform example 29, the first on-fixed period T1w is from an electrical angle of 270 degrees to an electrical angle of 330 degrees.

In waveform example 29, the second on-fixed period T2 includes a second on-fixed period T2u and a second on-fixed period T2v. In waveform example 29, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 270 degrees. In waveform example 29, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v.

In waveform example 29, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 29, the first on-fixed period T1u is 90 degrees, whereas the first on-fixed period T1v and the first on-fixed period T1w are 60 degrees. That is, in waveform example 29, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 42B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 29, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 29, the second fixed ON period T2v is 90 degrees, whereas the second fixed ON period T2u is 60 degrees, and there is no second fixed ON period T2w. That is, in waveform example 29, the second on-fixed period T2v is longer than the second on-fixed period T2u and the second on-fixed period T2w. Therefore, as shown in FIG. 42B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the U phase and the W phase.

As described above with reference to FIGS. 42A and 42B , in waveform example 29, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 29, the heat generation of the U-phase first semiconductor switching element Up and the V-phase second semiconductor switching element Vn can be simultaneously suppressed.

In addition, in waveform example 29, as shown in FIG. 42B , heat generation of the U-phase second semiconductor switching element Un, the V-phase first semiconductor switching element Vp, and the W-phase first semiconductor switching element Wp can be simultaneously suppressed.

As mentioned above, in the waveform example 1 to the waveform example 29 described with reference to FIGS. The first on-fixed period and the second on-fixed period of a phase are longer than the second on-fixed periods of other phases, and the second on-fixed period is longer than π/n and 2π/n or less. Preferably, it is 1.5π/n to 2π/n. Accordingly, heat generation can be efficiently suppressed. In addition, the lower limit may deviate slightly from π/n. In addition, the upper limit may deviate slightly from 2π/n. For example, in waveform example 1, the first on-fixed period T1u is 2π/n (=120 degrees), and the second on-fixed period T2u is 2π/n (=120 degrees). That is, in waveform example 1 to waveform example 29, the first fixed on period and the second fixed on period of the phase whose first fixed on period is longer than the first fixed period of other phases are longer than those of other phases. The second on-fixed periods of the phases whose second on-fixed periods are longer are all 2π/n. In addition, the first on-fixed period of the phase whose first on-fixed period is longer than the first on-fixed period of the other phases and the second on-fixed period of the phase are longer than the second on-fixed period of the other phases. The two connected fixed periods are mutually discontinuous. Therefore, when the temperature of a specific phase becomes a problem due to a problem of the cooling water channel or the like, the heat generation of the phase can be suppressed, thereby improving the reliability of the inverter. Alternatively, when an emergency stop occurs and the current continuously flows through the first semiconductor switching element of a certain phase and the second semiconductor switching element of another phase to increase the temperature, by performing the above operation when the emergency stop is exited and the operation is started , can suppress the heat generation of the semiconductor switching element after the sudden stop temperature rise, so that the temperature can be dropped rapidly, so the reliability of the inverter is improved.

In waveform example 13 to waveform example 29 described with reference to FIGS. 26A to 42B , among the n phases, the first on-fixed period of one phase and the second on-fixed period of the other phase are continuous with each other. For example, in waveform example 13, in the U-phase and V-phase among the three phases, the first on-fixed period T1u of the U-phase and the second on-fixed period T2v of the V-phase are continuous with each other. The total of the first on-fixed period of one phase and the second on-fixed period of the other phase is 3π/n. For example, in waveform example 13, the first on-fixed period T1u of U-phase is 90 degrees, and the second on-fixed period T2v of V-phase is 90 degrees. Therefore, the first on-fixed period T1u and the second on-fixed period of V-phase The total of T2v during the two ON fixations is 180 degrees (3π/n). In addition, the sum may deviate slightly from 3π/n. In addition, the first on-fixed period of one phase and the second on-fixed period of the other phase are respectively 3π/(2n). For example, in waveform example 13, the U-phase first on-fixed period T1u and the V-phase second on-fixed period T2v are 90 degrees (3π/(2n)). Therefore, in waveform example 13 to waveform example 29, when an emergency stop occurs and current continuously flows through the first semiconductor switching element of a certain phase and the second semiconductor switching element of another phase to increase the temperature, by Performing the above operation when exiting the emergency stop and starting the operation can suppress the heat generation of the semiconductor switching element after the emergency stop temperature rises, so that the temperature can be dropped rapidly, so the reliability of the inverter is improved.

The switching loss when the U-phase fixed period and the V-phase fixed period are changed will be described with reference to FIG. 43 . Fig. 43 is a graph showing switching loss.

As shown in Figure 43, the second on-fix period is applied within the electrical angle of 0 degrees to 60 degrees and the electrical angle of 330 degrees to 360 degrees, and the electrical angle is 60 degrees to 150 degrees. When the first constant ON period is applied, the switching loss of the first semiconductor switching element Up (UH) is 0.32. In addition, the switching loss of the second semiconductor switching element Vn(VL) was 0.32. At this time, the fixed period of the high side is 90 degrees.

When the electrical angle is 0 degrees to 70 degrees and the electrical angle is 330 degrees to 360 degrees, the second connection is applied during the fixed period, and the electrical angle is 70 degrees to 150 degrees. The first connection is applied In the case of a fixed period, the switching loss of the first semiconductor switching element Up (UH) is 0.39. In addition, the switching loss of the second semiconductor switching element Vn(VL) is 0.25. At this time, the fixed period of the high side is 80 degrees.

When the electrical angle is 0 degrees to 80 degrees and the electrical angle is 330 degrees to 360 degrees, the second connection is applied during the fixed period, and the electrical angle is 80 degrees to 150 degrees. The first connection is applied In the case of a fixed period, the switching loss of the first semiconductor switching element Up (UH) is 0.47. In addition, the switching loss of the second semiconductor switching element Vn(VL) is 0.18. At this time, the fixed period of the high side is 70 degrees.

When the electrical angle is 0 degrees to 90 degrees and the electrical angle is 330 degrees to 360 degrees, the second connection is applied during the fixed period, and the electrical angle is 90 degrees to 150 degrees. The first connection is applied In the case of a fixed period, the switching loss of the first semiconductor switching element Up (UH) is 0.56. In addition, the switching loss of the second semiconductor switching element Vn(VL) was 0.13. At this time, the fixed period of the high side is 60 degrees.

As described above with reference to FIG. 43 , it is preferable that both the first on-fixed period T1u and the second on-fixed period T2u are longer than π/3 (60 degrees) and not more than 2π/3 (120 degrees). More preferably, it is longer than 7π/18 (70 degrees) and 2π/3 (120 degrees) or less.

Next, switching of the UH_VL protection waveform will be further described with reference to FIG. 44 . FIG. 44 is a diagram for explaining switching of UH_VL protection waveforms.

In Fig. 44, the output voltage waveform and switching loss correspond to (n) waveform example 26 (Fig. 39A and 39B), (o) waveform example 27 (Fig. 40A and Fig. 40B) and (d) waveform example from the left. 16 (Fig. 29A and Fig. 29B).

The (n) waveform example 26 shown in the left figure is a waveform example in which the first fixed ON period T1v, the first fixed ON period T1w, the second fixed ON period T2u, and the second fixed ON period T2w are equalized. That is, it is an example of a waveform in which portions other than the first fixed ON period T1u and the second fixed ON period T2v are equalized.

The waveform example 27 (o) shown in the center figure is an example of a waveform obtained by extending the first on-fixed period T1v and the second on-fixed period T2u. That is, it is an example of waveforms in which U-phase and V-phase are emphasized.

(d) waveform example 16 shown in the figure on the right is a waveform example in which the first on-fixed period T1v and the second on-fixed period T2u are further extended from (o) waveform example 27 . That is, it is an example of waveforms in which U-phase and V-phase are emphasized.

As the diagram shifts to the right, the first on-fixed period T1v and the second on-fixed period T2u become longer. Therefore, the switching loss of the V-phase first semiconductor switching element Vp (high side) and the U-phase second semiconductor switching element Un (low side) decreases as the diagram shifts to the right.

Next, switching of the UH_VL protection waveform will be further described with reference to FIG. 45 . FIG. 45 is a diagram for explaining switching of UH_VL protection waveforms.

In FIG. 45 , the output voltage waveform and switching loss correspond to (n) waveform example 26 ( FIGS. 39A and 39B ) and (m) waveform example 25 ( FIGS. 38A and 38B ) in order from the left.

The (n) waveform example 26 shown in the left figure is a waveform example in which the first fixed ON period T1v, the first fixed ON period T1w, the second fixed ON period T2u, and the second fixed ON period T2w are equalized. That is, it is an example of a waveform in which portions other than the first fixed ON period T1u and the second fixed ON period T2v are equalized.

The (m) waveform example 25 shown in the figure on the right is a waveform example in which the first on-fixed period T1w and the second on-fixed period T2w are extended. In other words, it is an example of a waveform in which the W phase is emphasized.

As the figure shifts to the right, the first on-fixed period T1w and the second on-fixed period T2w become longer. Therefore, the switching loss of the W-phase first semiconductor switching element Wp (high side) and the W-phase second semiconductor switching element Wn (low side) decreases as the diagram shifts to the right.

Next, switching of the UH_VL protection waveform will be further described with reference to FIG. 46 . FIG. 46 is a diagram for explaining switching of UH_VL protection waveforms.

In Fig. 46, the output voltage waveform and switching loss correspond to (g) waveform example 19 (Fig. 32A and 32B), (n) waveform example 26 (Fig. 39A and 39B), and (a) waveform example from the left. 13 (Figure 26A and Figure 26B).

(g) Waveform Example 19 shown in the left figure is to reduce the second on-fixed period T2u and second on-fixed period T2w of (n) waveform example 26, and increase the first on-fixed period T1v and the first on-fixed period. Waveform example after a fixed period T1w. In other words, it is an example of a waveform in which the high side is emphasized.

(n) waveform example 26 shown in the center figure is a waveform example in which the first fixed ON period T1v, the first fixed ON period T1w, the second fixed ON period T2v, and the second fixed ON period T2w are equalized. That is, it is an example of a waveform in which portions other than the first fixed ON period T1u and the second fixed ON period T2u are equalized.

In the (a) waveform example 13 shown in the right figure, the first on-fixed period T1u and the first on-fixed period T1w of (n) waveform example 26 are reduced, and the second on-fixed period T2v and the second on-fixed period are increased. Waveform example after a fixed period T2w. In other words, it is an example of a waveform in which the low side is emphasized.

The detailed processing of step S186 shown in FIG. 21 will be described with reference to FIGS. 47 to 49 . That is, the processing at the time of modulation to suppress the temperature rise of the X-phase upper layer and the Y-phase lower layer will be described. Fig. 47 is a flowchart showing a method of switching guard waveforms. 48 and 49 are diagrams showing a method of switching guard waveforms. In addition, FIGS. 47 to 49 show how to switch guard waveforms when the U-phase is used as an example of the X-phase and the V-phase is used as an example of the Y-phase.

Step S502: The signal generator 120 judges whether the temperatures T_3-T_6 are equal to or less than the threshold T_Thr5. When the signal generator 120 determines that the temperatures T_3 to T_6 are not equal to or less than the threshold value T_Thr5 (step S502 : NO), the process proceeds to step S506 . When the signal generator 120 determines that the temperatures T_3 to T_6 are equal to or less than the threshold value T_Thr5 (step S502: Yes), the process proceeds to step S504.

Step S504: The signal generator 120 performs modulation in four protection modes. In detail, the signal generator 120 performs modulation with (i) waveform example 21 . Processing is complete.

Step S506: The signal generator 120 judges whether the temperatures T_5-T_6 are below the threshold T_Thr6. When the signal generating unit 120 determines that the temperatures T_5 to T_6 are not equal to or less than the threshold value T_Thr6 (step S506 : NO), the process proceeds to step S510 . When the signal generator 120 determines that the temperatures T_5 to T_6 are equal to or less than the threshold value T_Thr6 (step S506: Yes), the process proceeds to step S508.

Step S508: The signal generator 120 performs modulation in the middle of the three protection modes and the four protection modes. Modulation between the three protection schemes and the four protection schemes will be described later with reference to FIG. 48 . Processing is complete.

Step S510: The signal generator 120 determines whether the temperatures T_3-T_5 are below the threshold T_Thr7. When the signal generator 120 determines that the temperatures T_3 to T_5 are not equal to or less than the threshold value T_Thr7 (step S510 : NO), the process proceeds to step S514 . When the signal generating unit 120 determines that the temperatures T_3 to T_5 are equal to or less than the threshold value T_Thr7 (step S510: Yes), the process proceeds to step S512.

Step S512: The signal generator 120 performs modulation in three protection modes. Specifically, the signal generator 120 can protect the arms (semiconductor Modulation by means of switching elements). Processing is complete.

Step S514: The signal generator 120 judges whether the temperatures T_4-T_5 are below the threshold T_Thr8. When the signal generator 120 determines that the temperatures T_4 to T_5 are not equal to or less than the threshold value T_Thr8 (step S514: NO), the process proceeds to step S518. When the signal generator 120 determines that the temperatures T_4 to T_5 are equal to or less than the threshold value T_Thr8 (step S514: Yes), the process proceeds to step S516.

Step S516: The signal generating unit 120 performs modulation between the two protection schemes and the three protection schemes. Modulation between the two protection schemes and the three protection schemes will be described later with reference to FIG. 49 . Processing is complete.

Step S518: The signal generator 120 performs modulation in two protection modes. In detail, the signal generator 120 can protect (a) waveform example 13, (c) waveform example 15, (e) waveform example 17, (g) waveform example 19, (i) waveform example 21, and (p) waveform example The temperature in 28 is modulated by means of arms (semiconductor switching elements) of T_3 and T_4. Processing is complete.

Next, the detailed processing of step S508 shown in FIG. 47 will be described with reference to FIG. 48 . That is, the processing when modulation is performed between the three protection schemes and the four protection schemes will be described.

The signal generation unit 120 determines the positions of the first three arms (semiconductor switching elements) with high temperatures other than UH (first semiconductor switching element Up) and VL (second semiconductor switching element Vn). Hereinafter, in the description of FIG. 48 , the first three arms (semiconductor switching elements) with high temperatures other than “UH (first semiconductor switching element Up) and UL (second semiconductor switching element Un) are sometimes simply described as “ In addition, the order of the temperature of the first three arms is arbitrary. For example, the order of the temperature of the first three arms can be UL (the second semiconductor switching element Un), WH (the first semiconductor switching element Wp) and The order of WL (second semiconductor switching element Wn) may also be the order of UL (second semiconductor switching element Un), WL (second semiconductor switching element Wn) and WH (first semiconductor switching element Wp). Hereinafter, for In the same record, the order of the temperatures of the first three arms is also arbitrary.

When the signal generator 120 determines that the three arms with the highest temperature are UL (second semiconductor switching element Un), WH (first semiconductor switching element Wp), and WL (second semiconductor switching element Wn), in (i) In waveform example 21, the signal generator 120 applies 195 degrees to 195+45×(T_Thr6-(T_5-T_6))/T_Thr6 degrees to the first on-fixed period, and applies 270 degrees to 270+15×(T_Thr6-(T_5-T_6 ))/T_Thr6 degrees are applied to the second fixed-on period for modulation.

When the signal generator 120 determines that the three arms with the highest temperature are VH (first semiconductor switching element Vp), WH (first semiconductor switching element Wp), and WL (second semiconductor switching element Wn), in (k) In waveform example 23, the signal generation unit 120 applies 195 degrees to 195+15×(T_Thr6-(T_5-T_6))/T_Thr6 degrees to the first ON fixed period, and applies 240 degrees to 240+45×(T_Thr6-(T_5-T_6 ))/T_Thr6 degrees are applied to the second fixed-on period for modulation.

When the signal generator 120 determines that the three arms with the highest temperature are UL (second semiconductor switching element Un), VH (first semiconductor switching element Vp), and WL (second semiconductor switching element Wn), in (p) In waveform example 28, the signal generator 120 applies 195 degrees to 195+15×(T_Thr6-(T_5-T_6))/T_Thr6 degrees to the first on-fixed period, and applies 240 degrees to 240+45×(T_Thr6-(T_5-T_6 )))/T_Thr6 degrees are applied to the second on-on fixed period, and 285-285+45×(T_Thr6-(T_5-T_6))/T_Thr6 degrees are applied to the first on-on fixed period for modulation.

When the signal generator 120 determines that the three arms with the highest temperature are UL (second semiconductor switching element Un), VH (first semiconductor switching element Vp), and WH (first semiconductor switching element Wp), in (q) In waveform example 29, the signal generator 120 applies 150 degrees to 150+45×(T_Thr6-(T_5-T_6))/T_Thr6 degrees to the second on-fixed period, and applies 210 degrees to 210+30×(T_Thr6-(T_5-T_6 )))/T_Thr6 degrees are applied to the first fixed on period, and 270 to 270+15×(T_Thr6−(T_5−T_6))/T_Thr6 degrees are applied to the second fixed on period for modulation.

Next, the detailed processing of step S516 shown in FIG. 47 will be described with reference to FIG. 49 . That is, the processing when modulation is performed between the two protection schemes and the three protection schemes will be described.

As shown in FIG. 49 , when the positions of the two arms with the highest temperature and the priority of both are UL>WL and the arm at temperature T_5 is VH, process 1 is performed. In process 1, in (a) waveform example 13, the signal generation unit 120 modulates so that 210° to 210+60×(T_Thr8−(T_4−T_5))/T_Thr8° is applied to the first on-fixed period.

When the positions of the two arms with the highest temperature and the priority of both are UL>WL and the arm whose temperature is T_5 is WH, process 1 is performed. In process 1, in (a) waveform example 13, the signal generation unit 120 modulates so that 270° to 270+60×(T_Thr8−(T_4−T_5))/T_Thr8° is applied to the first on-fixed period.

When the position of the two arms with the highest temperature and the priority of both are UL<WL, and the arm whose temperature is T_5 is VH, process 1 is performed. In process 1, in (a) waveform example 13, the signal generation unit 120 modulates so that 210° to 210+60×(T_Thr8−(T_4−T_5))/T_Thr8° is applied to the first on-fixed period.

When the position of the two arms with the highest temperature and the priority of both are UL<WL and the arm whose temperature is T_5 is WH, process 2 is performed. In process 2, in (a) waveform example 13, the signal generation unit 120 modulates so that 270° to 270+60×(T_Thr8−(T_4−T_5))/T_Thr8° is applied to the first on-fixed period.

When the positions of the two arms with the highest temperature and the priority of both are UL>WH and the arm whose temperature is T_5 is VH, process 3 is performed. In process 3, in (a) waveform example 13, the signal generating unit 120 sets 150 degrees to 150+60×(T_Thr8-(T_4-T_5))/T_Thr8 degrees, 270 degrees to 270+60×(T_Thr8-(T_4-T_5 ))/T_Thr8 degrees are applied to the first fixed period for modulation.

When the positions of the two arms with the highest temperature and the priority of both are UL>WH and the arm whose temperature is T_5 is VL, process 2 is performed. In process 2, in (a) waveform example 13, the signal generation unit 120 modulates so that 270° to 270+60×(T_Thr8−(T_4−T_5))/T_Thr8° is applied to the first on-fixed period.

When the positions of the two arms with the highest temperature and the priority of both are UL>VH and the arm at temperature T_5 is WH, process 4 is performed. In process 4, in (c) waveform example 15, the signal generation unit 120 modulates so that 270° to 270+60×(T_Thr8−(T_4−T_5))/T_Thr8° is applied to the first on-fixed period.

When the position of the two arms with the highest temperature and the priority of both are UL>VH and the arm at temperature T_5 is WL, process 5 is performed. In process 5, in (c) waveform example 15, the signal generator 120 applies 150° to 150+60×(T_Thr8−(T_4−T_5))/T_Thr8° to the second on-fixed period, and applies 210° to 210+60×(T_Thr8−(T_4−T_5))/T_Thr8 degrees is applied to the first fixed period of on for modulation.

When the position of the two arms with the highest temperature and the priority of both are UL<VH and the arm whose temperature is T_5 is WH, process 6 is performed. In process 6, in (e) waveform example 17, the signal generator 120 applies 210 degrees to 210+60×(T_Thr8-(T_4-T_5))/T_Thr8 degrees to the second on-fixed period, and applies 270 degrees to 270+60×(T_Thr8-(T_4-T_5))/T_Thr8 degrees is applied to the first fixed-on period for modulation.

When the position of the two arms with the highest temperature and the priority of both are UL<VH and the arm whose temperature is T_5 is WL, process 7 is performed. In process 7, in (e) waveform example 17, the signal generation unit 120 modulates so that 150° to 150+60×(T_Thr8−(T_4−T_5))/T_Thr8° is applied to the second on-fixed period.

When the position of the two arms with the highest temperature and the priority of both are VH>WL and the arm at temperature T_5 is WL, process 7 is performed. In process 7, in (e) waveform example 17, the signal generation unit 120 modulates so that 150° to 150+60×(T_Thr8−(T_4−T_5))/T_Thr8° is applied to the second on-fixed period.

When the positions of the two arms with the highest temperature and the priority of both are VH>WL and the arm at temperature T_5 is WH, process 8 is performed. In process 8, in (e) waveform example 17, the signal generator 120 applies 150 degrees to 150+60×(T_Thr8-(T_4-T_5))/T_Thr8 degrees to the second on-fixed period, and applies 270 degrees to 270+60×(T_Thr8-(T_4-T_5))/T_Thr8 degrees is applied to the first fixed-on period for modulation.

When the position of the two arms with the highest temperature and the priority of both are VH>WH and the arm whose temperature is T_5 is UL, process 9 is performed. In process 9, in (g) waveform example 19, the signal generation unit 120 modulates so that 210° to 210+60×(T_Thr8−(T_4−T_5))/T_Thr8° is applied to the second ON constant period.

When the position of the two arms with the highest temperature and the priority of both are VH>WH and the arm at temperature T_5 is WL, process 10 is performed. In process 10, in (g) waveform example 19, the signal generation unit 120 modulates so that 150° to 150+60×(T_Thr8−(T_4−T_5))/T_Thr8° is applied to the second on-fixed period.

When the position of the two arms with the highest temperature and the priority of both are VH<WH and the arm whose temperature is T_5 is UL, process 9 is performed. In process 9, in (g) waveform example 19, the signal generation unit 120 modulates so that 210° to 210+60×(T_Thr8−(T_4−T_5))/T_Thr8° is applied to the second ON constant period.

When the position of the two arms with the highest temperature and the priority of both are VH<WH and the arm at temperature T_5 is WL, process 10 is performed. In process 10, in (g) waveform example 19, the signal generation unit 120 modulates so that 150° to 150+60×(T_Thr8−(T_4−T_5))/T_Thr8° is applied to the second on-fixed period.

When the position of the two arms with the highest temperature and the priority of both are UL<WH and the arm whose temperature is T_5 is VH, process 11 is performed. In process 11, in (i) waveform example 21, the signal generation unit 120 modulates so that 150° to 150+60×(T_Thr8−(T_4−T_5))/T_Thr8° is applied to the first on-fixed period.

When the position of the two arms with the highest temperature and the priority of both are UL<WH and the arm whose temperature is T_5 is WL, process 12 is performed. In the process 12 , the signal generator 120 performs modulation with (i) waveform example 21 .

When the positions of the two arms with the highest temperature and the priority of both are WH>WL and the arm whose temperature is T_5 is UL, process 12 is performed. In the process 12 , the signal generator 120 performs modulation with (i) waveform example 21 .

When the positions of the two arms with the highest temperature and the priority of both are WH>WL, and the arm whose temperature is T_5 is VH, process 13 is performed. In process 13, in (i) waveform example 21, the signal generation unit 120 modulates so as to apply 210° to 210+60×(T_Thr8−(T_4−T_5))/T_Thr8° for the first on-fixed period.

When the position of the two arms with the highest temperature and the priority of both are WH<WL and the arm whose temperature is T_5 is UL, process 12 is performed. In the process 12 , the signal generator 120 performs modulation with (i) waveform example 21 .

When the position of the two arms with the highest temperature and the priority of both are VH<WL and the arm whose temperature is T_5 is UL, process 14 is performed. In the process 14 , the signal generator 120 performs modulation with the (p) waveform example 28 .

When the position of the two arms with the highest temperature and the priority of both are VH<WL and the arm at temperature T_5 is WH, process 15 is performed. In process 15 , in (p) waveform example 28 , the signal generation unit 120 modulates so that 270°˜270+60×(T_Thr8−(T_4−T_5))/T_Thr8° is applied to the first on-fixed period.

As described above with reference to FIGS. 47 to 49 , the protection operation mode includes the second selection protection operation mode in which the first semiconductor switching element of one phase and the second semiconductor switching element of the other phase Semiconductor switching elements for protection. The first on-fixed period of one phase is continuous with the second on-fixed period of the other phase. The second selection protection action mode includes a plurality of k protection action modes, and based on the temperature information, k protection action modes are selected, and in the plurality of k protection action modes, the first semiconductor switch except one phase k (k is a natural number equal to or less than 2n-3) of the first semiconductor switching element or the second semiconductor switching element among the first semiconductor switching element and the second semiconductor switching element other than the element and the second semiconductor switching element of the other phase components are protected. Therefore, when an emergency stop occurs and the current continuously flows through the first semiconductor switching element of a certain phase and the second semiconductor switching element of another phase to increase the temperature, by performing the above operation when the emergency stop is exited and the operation is started , the temperature rise of the first semiconductor switching element of a certain phase and the second semiconductor switching element of another phase can be suppressed to the greatest extent, and at the same time, the temperature rise of the semiconductor switching element required by the temperature conditions of other semiconductor switching elements is also suppressed, The reliability of the inverter is improved.

As described above with reference to FIGS. 1 to 49 , the motor drive circuit 100 has a plurality of operation modes with different PWM duty waveforms, and has a function of switching the plurality of operation modes during power conversion. At least one of the plurality of operation modes is a protection operation mode. By adopting the optimum operation mode required by switching the operation mode, the temperature rise of the power converter (inverter) can be efficiently suppressed and the reliability can be improved.

The protection operation mode has a plurality of protection operation modes. In the plurality of protection operation modes, during one cycle of the AC output, the first fixed period of connection and the second fixed period of connection occupied by each phase At least one of the ratios is different. Therefore, it is possible to support various protection modes. For example, in addition to the normal mode (one type), it is also possible to perform protection (multiple types) centering on each phase.

Switching between the plurality of protection operation modes and the plurality of protection operation modes is performed based on temperature information of at least one of the first semiconductor switching element and the second semiconductor switching element. The temperature information is, for example, the temperature acquired by the six temperature sensors 20 of each semiconductor switching element. In addition, the temperature sensor 20 may be arranged in the vicinity of some semiconductor switching elements, and the temperature of the semiconductor switching elements where the temperature sensor 20 is not arranged may be estimated by calculation. Alternatively, the ambient temperature may be monitored, and the temperature may be estimated using the values of a current sensor and a voltage sensor (not shown) provided in the motor drive circuit 100 . The ambient temperature is, for example, the air temperature, the temperature of the substrate, and the temperature of cooling water. The cooling water is liquid for cooling the motor drive circuit 100 . By switching between a plurality of protection operation modes and a plurality of protection operation modes based on temperature information of at least one of the first semiconductor switching element and the second semiconductor switching element, it is possible to selectively suppress heat generation of the semiconductor switching element whose temperature becomes higher and Facilitates heat dissipation, thereby increasing the reliability of power converters.

In addition, the protective action mode has at least four protective action modes. Therefore, it is possible to support various protection modes. For example, in addition to the normal mode (one type), it is also possible to perform protection (multiple types) centering on each phase.

Other waveform examples will be described with reference to FIGS. 50A to 66B .

Waveform example 30 will be described with reference to FIGS. 50A and 50B . FIG. 50A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 50B is a graph showing switching loss.

As shown in Figure 50A, the waveform example 30 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 30 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 90 degrees to 210 degrees. In addition, the waveform example 30 is a waveform in which the output of any phase is fixed at 0 within an electrical angle of 0 degrees to an electrical angle of 90 degrees and an electrical angle of 210 degrees to an electrical angle of 360 degrees. In waveform example 30, the high-side ON application period T3 is from an electrical angle of 90 degrees to an electrical angle of 210 degrees. In addition, in waveform example 30, the low-side ON application period T4 is the electrical angle of 0 degrees to the electrical angle of 90 degrees and the electrical angle of 210 degrees to the electrical angle of 360 degrees.

In the waveform example 30, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1v. In waveform example 30, the first on-fixed period T1u is from an electrical angle of 90 degrees to an electrical angle of 150 degrees. In waveform example 30, the electrical angle of 150° to 210° is the first on-fixed period T1v.

In the waveform example 30, the second on-fixed period T2 includes a second on-fixed period T2u and a second on-fixed period T2v. In waveform example 30, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 30, the electrical angle of 0 degrees to the electrical angle of 90 degrees and the electrical angle of 330 degrees to the electrical angle of 360 degrees are the second on-fixed period T2v.

In the waveform example 30, in the U phase among the three phases, the first on-fixed period T1u is different from the first on-fixed period T1w. In detail, in waveform example 30, the first on-fixed period T1u is 60 degrees, whereas there is no first on-fixed period T1w. That is, in the waveform example 30, the first on-fixed period T1u is longer than the first on-fixed period T1w. In addition, the first on-fixed period T1v is the same as the first on-fixed period T1u. Therefore, as shown in FIG. 50B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the W phase.

In waveform example 30, the second on-fixed period T2u is different from the second on-fixed period T2w. In detail, in waveform example 30, the second on-fixed period T2u is 120 degrees, whereas there is no second on-fixed period T2w. That is, in the waveform example 30, the second on-fixed period T2u is longer than the second on-fixed period T2w. In addition, the second on-fixed period T2v is the same as the second on-fixed period T2u. Therefore, as shown in FIG. 50B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the W phase.

As described above with reference to FIGS. 50A and 50B , in waveform example 30, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In the waveform example 30, heat generation of the U-phase second semiconductor switching element Un and the V-phase second semiconductor switching element Vn can be simultaneously suppressed.

In addition, in waveform example 30, as shown in FIG. 50B , heat generation of the U-phase first semiconductor switching element Up and the V-phase first semiconductor switching element Vp can be simultaneously suppressed.

Waveform example 31 will be described with reference to FIGS. 51A and 51B . FIG. 51A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 51B is a graph showing switching loss.

As shown in Fig. 51A, the waveform example 31 is as follows, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 31 is a waveform in which the output of any phase is fixed at 1 within an electrical angle of 45 degrees to 135 degrees and an electrical angle of 180 degrees to 210 degrees. In addition, the waveform example 31 is a waveform such that any phase is within an electrical angle of 0 degrees to an electrical angle of 45 degrees, an electrical angle of 135 degrees to 180 degrees, and an electrical angle of 210 degrees to 360 degrees. The output is fixed at 0. In the waveform example 31, the high-side ON application period T3 is the electrical angle of 45 degrees to the electrical angle of 135 degrees and the electrical angle of 180 degrees to the electrical angle of 210 degrees. In addition, in waveform example 31, the electrical angle of 0 degrees to 45 degrees, the electrical angle of 135 degrees to 180 degrees, and the electrical angle of 210 degrees to 360 degrees are low-side ON application periods. T4.

In waveform example 31, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1v. In waveform example 31, the first on-fixed period T1u is from an electrical angle of 45 degrees to an electrical angle of 135 degrees. In waveform example 31, an electrical angle of 180 degrees to an electrical angle of 210 degrees is the first on-fixed period T1v.

In waveform example 31, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 31, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 31, the electrical angle of 0° to 45° and the electrical angle of 330° to 360° are the second on-fixed period T2v. In waveform example 31, the second on-fixed period T2w is from an electrical angle of 135 degrees to an electrical angle of 180 degrees.

In the waveform example 31, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 31, the first on-fixed period T1u is 90 degrees, whereas the first on-fixed period T1v and the first on-fixed period T1w are 30 degrees. That is, in waveform example 31, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 51B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 31, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in the waveform example 31, the second on-fixed period T2u is 120 degrees, whereas the second on-fixed period T2v is 75 degrees, and the second on-fixed period T2w is 45 degrees. That is, in waveform example 31, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 51B , the switching loss of the U-phase second semiconductor switching element Un (L (low side)) is smaller than that of the V-phase and W-phase.

As described above with reference to FIGS. 51A and 51B , in waveform example 31, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In the waveform example 31, heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in the waveform example 31, as shown in FIG. 51B , the heat generation of the V-phase first semiconductor switching element Vp, the V-phase second semiconductor switching element Vn, and the W-phase second semiconductor switching element Wn can be simultaneously suppressed.

Waveform example 32 will be described with reference to FIGS. 52A and 52B . FIG. 52A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 52B is a graph showing switching loss.

As shown in FIG. 52A, the waveform example 32 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 32 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 60° to 120° and an electrical angle of 150° to 210°. In addition, the waveform example 32 is a waveform such that any phase is within an electrical angle of 0 degrees to an electrical angle of 60 degrees, an electrical angle of 120 degrees to an electrical angle of 150 degrees, and an electrical angle of 210 degrees to an electrical angle of 360 degrees. The output is fixed at 0. In the waveform example 32, the high-side ON application period T3 is the electrical angle of 60 degrees to the electrical angle of 120 degrees and the electrical angle of 150 degrees to the electrical angle of 210 degrees. In addition, in waveform example 32, the electrical angle of 0° to 60°, the electrical angle of 120° to 150°, and the electrical angle of 210° to 360° are low-side ON application periods. T4.

In the waveform example 32, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1v. In waveform example 32, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 120 degrees. In waveform example 32, the electrical angle of 150° to 210° is the first on-fixed period T1v.

In the waveform example 32, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 32, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In the waveform example 32, the electrical angle of 0° to 60° and the electrical angle of 330° to 360° are the second on-fixed period T2v. In the waveform example 32, the second on-fixed period T2w is from an electrical angle of 120 degrees to an electrical angle of 150 degrees.

In waveform example 32, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1w. In detail, in waveform example 32, the first on-fixed period T1u is 60 degrees, whereas there is no first on-fixed period T1w. That is, in the waveform example 32, the first on-fixed period T1u is longer than the first on-fixed period T1w. In addition, the first on-fixed period T1v is the same as the first on-fixed period T1u. Therefore, as shown in FIG. 52B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the W phase.

In waveform example 32, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in the waveform example 32, the second fixed ON period T2u is 120 degrees, whereas the second fixed ON period T2v is 90 degrees, and the second fixed ON period T2w is 30 degrees. That is, in waveform example 32, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 52B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 52A and 52B , in waveform example 32, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In the waveform example 32, the heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in waveform example 32, as shown in FIG. 52B , heat generation of the V-phase first semiconductor switching element Vp, the V-phase second semiconductor switching element Vn, and the W-phase second semiconductor switching element Wn can be simultaneously suppressed.

Waveform example 33 will be described with reference to FIGS. 53A and 53B . FIG. 53A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 53B is a graph showing switching loss.

As shown in FIG. 53A, the waveform example 33 is as follows, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0. . In detail, waveform example 33 has the following waveforms, that is, within the range of electrical angles from 60 degrees to 120 degrees, electrical angles from 180 degrees to 210 degrees, and electrical angles from 330 degrees to 360 degrees. , the output of any phase is fixed at 1. In addition, waveform example 33 is a waveform in which any phase is within the electrical angle of 0 degrees to 60 degrees, the electrical angle of 120 degrees to 180 degrees, and the electrical angle of 210 degrees to 330 degrees. The output is fixed at 0. In waveform example 33, the high-side ON application period T3 is the electrical angle of 60° to 120°, the electrical angle of 180° to 210°, and the electrical angle of 330° to 360°. In addition, in waveform example 33, the electrical angle of 0° to 60°, the electrical angle of 120° to 180°, and the electrical angle of 210° to 330° are low-side ON application periods. T4.

In waveform example 33, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In the waveform example 33, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 120 degrees. In the waveform example 33, the first on-fixed period T1v is from an electrical angle of 180 degrees to an electrical angle of 210 degrees. In the waveform example 33, the electrical angle of 330 degrees to the electrical angle of 360 degrees is the first on-fixed period T1w.

In waveform example 33, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 33, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 33, the second on-fixed period T2v is the electrical angle from 0° to 60°. In waveform example 33, the second on-fixed period T2w is from an electrical angle of 120 degrees to an electrical angle of 180 degrees.

In waveform example 33, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in waveform example 33, the first on-fixed period T1u is 60 degrees, whereas the first on-fixed period T1v and the first on-fixed period T1w are 30 degrees. That is, in waveform example 33, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 53B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 33, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in the waveform example 33, the second on-fixed period T2u is 120 degrees, while the second on-fixed period T2v and the second on-fixed period T2w are 60 degrees. That is, in waveform example 33, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 53B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 53A and 53B , in waveform example 33, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In the waveform example 33, the heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be suppressed at the same time.

In addition, in waveform example 33, as shown in FIG. 53B , the V-phase first semiconductor switching element Vp, the V-phase second semiconductor switching element Vn, the W-phase first semiconductor switching element Wp, and the W-phase The heat generation of the second semiconductor switching element Wn.

Waveform example 34 will be described with reference to FIGS. 54A and 54B . FIG. 54A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 54B is a graph showing switching loss.

As shown in FIG. 54A, the waveform example 34 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 34 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 75 degrees to 105 degrees and an electrical angle of 150 degrees to 240 degrees. In addition, waveform example 34 is a waveform such that any phase is within the electrical angle of 0 degrees to 75 degrees, the electrical angle of 105 degrees to 150 degrees, and the electrical angle of 240 degrees to 360 degrees. The output is fixed at 0. In waveform example 34, the high-side ON application period T3 is the electrical angle of 75° to 105° and the electrical angle of 150° to 240°. In addition, in waveform example 34, the low-side ON application period T4 is the electrical angle of 105 degrees to the electrical angle of 150 degrees and the electrical angle of 240 degrees to the electrical angle of 360 degrees.

In the waveform example 34, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1v. In waveform example 34, the first on-fixed period T1u is from an electrical angle of 75 degrees to an electrical angle of 105 degrees. In waveform example 34, the electrical angle of 150° to 240° is the first on-fixed period T1v.

In waveform example 34, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 34, the second on-fixed period T2u is from an electrical angle of 240 degrees to an electrical angle of 330 degrees. In waveform example 34, the electrical angle of 0° to 75° and the electrical angle of 330° to 360° are the second on-fixed period T2v. In waveform example 34, the second on-fixed period T2w is from an electrical angle of 105 degrees to an electrical angle of 150 degrees.

In the waveform example 34, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. Specifically, in the waveform example 34, the first on-fixed period T1v is 90 degrees, whereas the first on-fixed period T1u is 30 degrees, and there is no first on-fixed period T1w. That is, in waveform example 34, the first on-fixed period T1v is longer than the first on-fixed period T1u and the first on-fixed period T1w. Therefore, as shown in FIG. 54B , the switching loss of the V-phase first semiconductor switching element Vp (H (high side)) is smaller than that of the U-phase and W-phase.

In waveform example 34, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in waveform example 34, the second fixed ON period T2v is 105 degrees, whereas the second fixed ON period T2u is 90 degrees, and the second fixed ON period T2w is 45 degrees. That is, in waveform example 34, the second on-fixed period T2v is longer than the second on-fixed period T2u and the second on-fixed period T2w. Therefore, as shown in FIG. 54B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the U phase and the W phase.

As described above with reference to FIGS. 54A and 54B , in waveform example 34, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 34, the heat generation of the V-phase first semiconductor switching element Vp and the V-phase second semiconductor switching element Vn can be simultaneously suppressed.

In addition, in the waveform example 34, as shown in FIG. 54B , the heat generation of the U-phase second semiconductor switching element Up, the U-phase second semiconductor switching element Un, and the W-phase second semiconductor switching element Wn can be simultaneously suppressed.

Waveform example 35 will be described with reference to FIGS. 55A and 55B . FIG. 55A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 55B is a graph showing switching loss.

As shown in FIG. 55A, waveform example 35 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, the waveform example 35 has the following waveforms, that is, within the electrical angle of 75 degrees to 105 degrees, the electrical angle of 150 degrees to 210 degrees, and the electrical angle of 330 degrees to 360 degrees, any The output of one phase is fixed at 1. In addition, waveform example 35 is a waveform in which any of the electrical angles from 0° to 75°, from 105° to 150°, and from 210° to 330° are The phase output is fixed at 0. In waveform example 35, the high-side ON application period T3 is the electrical angle of 75 degrees to 105 degrees, the electrical angle of 150 degrees to 210 degrees, and the electrical angle of 330 degrees to 360 degrees. In addition, in waveform example 35, the electrical angle of 0 degrees to 75 degrees, the electrical angle of 105 degrees to 150 degrees, and the electrical angle of 210 degrees to 330 degrees are low-side ON application periods. T4.

In waveform example 35, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 35, the first on-fixed period T1u is from an electrical angle of 75 degrees to an electrical angle of 105 degrees. In waveform example 35, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 210 degrees. In waveform example 35, the first on-fixed period T1w is from an electrical angle of 330 degrees to an electrical angle of 360 degrees.

In waveform example 35, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 35, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 35, the electrical angle of 0° to 75° is the second on-fixed period T2v. In waveform example 35, the second on-fixed period T2w is from an electrical angle of 105 degrees to an electrical angle of 150 degrees.

In waveform example 35, in the U phase of the three phases, the first on-fixed period T1v is different from the first on-fixed period T1u and the first on-fixed period T1w. Specifically, in waveform example 35, the first on-fixed period T1v is 60 degrees, whereas the first on-fixed period T1u and the first on-fixed period T1w are 30 degrees. That is, in waveform example 35, the first on-fixed period T1v is longer than the first on-fixed period T1u and the first on-fixed period T1w. Therefore, as shown in FIG. 55B , the switching loss of the V-phase first semiconductor switching element Vp (H (high side)) is smaller than that of the U-phase and W-phase.

In waveform example 35, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in the waveform example 35, the second on-fixed period T2u is 120 degrees, whereas the second on-fixed period T2v is 75 degrees, and the second on-fixed period T2w is 45 degrees. That is, in waveform example 35, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 55B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 55A and 55B , in waveform example 35, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 35, the heat generation of the V-phase first semiconductor switching element Vp and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in waveform example 35, as shown in FIG. 55B , the U-phase first semiconductor switching element Up, the V-phase second semiconductor switching element Vn, the W-phase first semiconductor switching element Wp, and the W-phase The heat generation of the second semiconductor switching element Wn.

Waveform example 36 will be described with reference to FIGS. 56A and 56B . FIG. 56A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 56B is a graph showing switching loss.

As shown in FIG. 56A, waveform example 36 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 36 is a waveform in which the output of any phase is fixed at 1 within an electrical angle of 150° to 240° and an electrical angle of 330° to 360°. In addition, the waveform example 36 is a waveform in which the output of any phase is fixed at 0 within an electrical angle of 0 degrees to an electrical angle of 150 degrees and an electrical angle of 240 degrees to an electrical angle of 330 degrees. In waveform example 36, the high-side ON application period T3 is the electrical angle of 150° to 240° and the electrical angle of 330° to 360°. In addition, in the waveform example 36, the low-side ON application period T4 is the electrical angle of 0 degrees to the electrical angle of 150 degrees and the electrical angle of 240 degrees to the electrical angle of 330 degrees.

In the waveform example 36, the first on-fixed period T1 includes a first on-fixed period T1v and a first on-fixed period T1w. In waveform example 36, the electrical angle of 150° to 240° is the first on-fixed period T1v. In waveform example 36, the first on-fixed period T1w is from an electrical angle of 330 degrees to an electrical angle of 360 degrees.

In waveform example 36, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 36, the second on-fixed period T2u is from an electrical angle of 240 degrees to an electrical angle of 330 degrees. In waveform example 36, the second on-fixed period T2v is the electrical angle from 0° to 90°. In waveform example 36, the second on-fixed period T2w is from an electrical angle of 90 degrees to an electrical angle of 150 degrees.

In the waveform example 36, in the V phase among the three phases, the first on-fixed period T1v is different from the first on-fixed period T1u and the first on-fixed period T1w. Specifically, in waveform example 36, the first on-fixed period T1v is 90 degrees, whereas the first on-fixed period T1u is absent, and the first on-fixed period T1w is 30 degrees. That is, in waveform example 36, the first on-fixed period T1v is longer than the first on-fixed period T1u and the first on-fixed period T1w. Therefore, as shown in FIG. 56B , the switching loss of the V-phase first semiconductor switching element Vp (H (high side)) is smaller than that of the U-phase and W-phase.

In waveform example 36, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in waveform example 36, the second on-fixed period T2u is 90 degrees, whereas the second on-fixed period T2w is 60 degrees. That is, in waveform example 36, the second on-fixed period T2u is longer than the second on-fixed period T2w. In addition, the second on-fixed period T2v is the same as the second on-fixed period T2u. Therefore, as shown in FIG. 56B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the W phase.

As described above with reference to FIGS. 56A and 56B , in waveform example 36, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 36, the heat generation of the V-phase first semiconductor switching element Vp and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in the waveform example 36, as shown in FIG. 56B , the heat generation of the V-phase second semiconductor switching element Vn, the W-phase first semiconductor switching element Wp, and the W-phase second semiconductor switching element Wn can be simultaneously suppressed.

Waveform example 37 will be described with reference to FIGS. 57A and 57B . FIG. 57A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 57B is a graph showing switching loss.

As shown in FIG. 57A, waveform example 37 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, the waveform example 37 has the following waveforms, that is, within the electrical angle of 0 degrees to 30 degrees, the electrical angle of 150 degrees to 210 degrees, and the electrical angle of 330 degrees to 360 degrees, any The output of one phase is fixed at 1. In addition, waveform example 37 is a waveform in which the output of any one phase is fixed at 0 within an electrical angle of 30 degrees to 150 degrees and an electrical angle of 210 degrees to 330 degrees. In waveform example 37, the high-side ON application period T3 is the electrical angle of 0° to 30°, the electrical angle of 150° to 210°, and the electrical angle of 330° to 360°. In addition, in waveform example 37, an electrical angle of 30 degrees to an electrical angle of 150 degrees and an electrical angle of 210 degrees to an electrical angle of 330 degrees are low-side ON application periods T4.

In waveform example 37, the first on-fixed period T1 includes a first on-fixed period T1v and a first on-fixed period T1w. In waveform example 37, an electrical angle of 150 degrees to an electrical angle of 210 degrees is the first on-fixed period T1v. In the waveform example 37, the electrical angle of 0° to 30° and the electrical angle of 330° to 360° are the first ON fixed period T1w.

In waveform example 37, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 37, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 37, the second on-fixed period T2v is from an electrical angle of 30 degrees to an electrical angle of 90 degrees. In waveform example 37, the electrical angle of 90° to 150° is the second on-fixed period T2w.

In the waveform example 37, in the U phase among the three phases, the first on-fixed period T1v is different from the first on-fixed period T1u. In detail, in the waveform example 37, the first on-fixed period T1v is 60 degrees, but there is no first on-fixed period T1u. That is, in waveform example 37, the first ON fixed period T1v is longer than the first ON fixed period T1u. In addition, the first on-fixed period T1w is the same as the first on-fixed period T1v. Therefore, as shown in FIG. 57B , the switching loss of the first semiconductor switching element Up (H (high side)) of the V phase is smaller than that of the U phase.

In waveform example 37, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in the waveform example 37, the second on-fixed period T2u is 120 degrees, whereas the second on-fixed period T2v and the second on-fixed period T2w are 60 degrees. That is, in waveform example 37, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 57B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 57A and 57B , in waveform example 37, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 37, the heat generation of the V-phase first semiconductor switching element Vp and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in the waveform example 37, as shown in FIG. 57B , the heat generation of the V-phase second semiconductor switching element Vn, the W-phase first semiconductor switching element Wp, and the W-phase second semiconductor switching element Wn can be simultaneously suppressed.

Waveform example 38 will be described with reference to FIGS. 58A and 58B . FIG. 58A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 58B is a graph showing switching loss.

As shown in FIG. 58A, waveform example 38 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 38 is a waveform in which the output of any phase is fixed at 1 within an electrical angle of 45° to 135° and an electrical angle of 150° to 240°. In addition, waveform example 38 is a waveform in which any phase is within the electrical angle of 0 degrees to 45 degrees, the electrical angle of 135 degrees to 150 degrees, and the electrical angle of 240 degrees to 360 degrees. The output is fixed at 0. In waveform example 38, the high-side-on application period T3 is the electrical angle of 45 degrees to the electrical angle of 135 degrees and the electrical angle of 150 degrees to the electrical angle of 240 degrees. In addition, in waveform example 38, the electrical angle of 0 degrees to 45 degrees, the electrical angle of 135 degrees to 150 degrees, and the electrical angle of 240 degrees to 360 degrees are low-side ON application periods. T4.

In the waveform example 38, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1v. In waveform example 38, the first on-fixed period T1u is from an electrical angle of 45° to an electrical angle of 135°. In waveform example 38, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 240 degrees.

In waveform example 38, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 38, the second on-fixed period T2u is from an electrical angle of 240 degrees to an electrical angle of 330 degrees. In waveform example 38, the electrical angle of 0° to 45° and the electrical angle of 330° to 360° are the second on-fixed period T2v. In waveform example 38, the second on-fixed period T2w is from an electrical angle of 135 degrees to an electrical angle of 150 degrees.

In the waveform example 38, in the U phase among the three phases, the first on-fixed period T1u is different from the first on-fixed period T1w. In detail, in waveform example 38, the first on-fixed period T1u is 90 degrees, but there is no first on-fixed period T1w. That is, in waveform example 38, the first on-fixed period T1u is longer than the first on-fixed period T1w. In addition, the first on-fixed period T1v is the same as the first on-fixed period T1u. Therefore, as shown in FIG. 58B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the W phase.

In waveform example 38, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in the waveform example 38, the second on-fixed period T2u is 90 degrees, while the second on-fixed period T2v is 75 degrees, and the second on-fixed period T2w is 15 degrees. That is, in waveform example 38, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 58B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 58A and 58B , in waveform example 38, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 38, the heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in waveform example 38, as shown in FIG. 58B , heat generation of the V-phase first semiconductor switching element Vp, the V-phase second semiconductor switching element Vn, and the W-phase second semiconductor switching element Wn can be simultaneously suppressed.

Waveform example 39 will be described with reference to FIGS. 59A and 59B . FIG. 59A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 59B is a graph showing switching loss.

As shown in FIG. 59A, waveform example 39 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 39 has the following waveforms, that is, within the electrical angle of 45 degrees to 135 degrees, the electrical angle of 150 degrees to 210 degrees, and the electrical angle of 330 degrees to 360 degrees, any The output of one phase is fixed at 1. In addition, Waveform Example 39 is a waveform in which any phase is within an electrical angle of 0 degrees to an electrical angle of 45 degrees, an electrical angle of 135 degrees to 150 degrees, and an electrical angle of 210 degrees to 330 degrees. The output is fixed at 0. In waveform example 39, the high-side ON application period T3 is the electrical angle of 45 degrees to 135 degrees, the electrical angle of 150 degrees to 210 degrees, and the electrical angle of 330 degrees to 360 degrees. In addition, in waveform example 39, the electrical angle of 0° to 45°, the electrical angle of 135° to 150°, and the electrical angle of 210° to 330° are low-side ON application periods. T4.

In waveform example 39, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 39, the first on-fixed period T1u is from an electrical angle of 45 degrees to an electrical angle of 135 degrees. In waveform example 39, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 210 degrees. In waveform example 39, an electrical angle of 330 degrees to an electrical angle of 360 degrees is the first on-fixed period T1w.

In waveform example 39, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 39, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 39, the second on-fixed period T2v is from an electrical angle of 0° to an electrical angle of 45°. In waveform example 39, the second on-fixed period T2w is from an electrical angle of 135 degrees to an electrical angle of 150 degrees.

In waveform example 39, in the U phase of the three phases, the first on-fixed period T1u is different from the first on-fixed period T1v and the first on-fixed period T1w. In detail, in waveform example 39, the first on-fixed period T1u is 90 degrees, whereas the first on-fixed period T1v is 60 degrees, and the first on-fixed period T1w is 30 degrees. That is, in waveform example 39, the first on-fixed period T1u is longer than the first on-fixed period T1v and the first on-fixed period T1w. Therefore, as shown in FIG. 59B , the switching loss of the first semiconductor switching element Up (H (high side)) of the U phase is smaller than that of the V phase and the W phase.

In waveform example 39, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. In detail, in waveform example 39, the second on-fixed period T2u is 120 degrees, whereas the second on-fixed period T2v is 45 degrees, and the second on-fixed period T2w is 15 degrees. That is, in waveform example 39, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 59B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 59A and 59B , in waveform example 39, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 39, the heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in waveform example 39, as shown in FIG. 59B , the V-phase first semiconductor switching element Vp, the V-phase second semiconductor switching element Vn, the W-phase first semiconductor switching element Wp, and the W-phase The heat generation of the second semiconductor switching element Wn.

Waveform example 40 will be described with reference to FIGS. 60A and 60B . FIG. 60A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 60B is a graph showing switching loss.

As shown in FIG. 60A, the waveform example 40 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0. . In detail, the waveform example 40 is a waveform as follows, that is, any electrical angle is within an electrical angle of 60 degrees to 120 degrees, an electrical angle of 150 degrees to 240 degrees, and an electrical angle of 330 degrees to 360 degrees. The output of one phase is fixed at 1. In addition, the waveform example 40 is a waveform such that any electrical angle is within an electrical angle of 0 degrees to an electrical angle of 60 degrees, an electrical angle of 120 degrees to an electrical angle of 150 degrees, and an electrical angle of 240 degrees to an electrical angle of 330 degrees. The phase output is fixed at 0. In waveform example 40, the high-side ON application period T3 is the electrical angle of 60° to 120°, the electrical angle of 150° to 240°, and the electrical angle of 330° to 360°. In addition, in waveform example 40, the electrical angle of 0° to 60°, the electrical angle of 120° to 150°, and the electrical angle of 240° to 330° are low-side ON application periods. T4.

In the waveform example 40, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 40, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 120 degrees. In waveform example 40, the electrical angle of 150° to 240° is the first on-fixed period T1v. In the waveform example 40, the first on-fixed period T1w is from an electrical angle of 330 degrees to an electrical angle of 360 degrees.

In the waveform example 40, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 40, the second on-fixed period T2u is from an electrical angle of 240 degrees to an electrical angle of 330 degrees. In waveform example 40, the second on-fixed period T2v is the electrical angle from 0° to 60°. In the waveform example 40, the second on-fixed period T2w is from an electrical angle of 120 degrees to an electrical angle of 150 degrees.

In the waveform example 40, in the V phase among the three phases, the first on-fixed period T1v is different from the first on-fixed period T1u and the first on-fixed period T1w. Specifically, in waveform example 40, the first on-fixed period T1v is 90 degrees, whereas the first on-fixed period T1u is 60 degrees, and the first on-fixed period T1w is 30 degrees. That is, in the waveform example 40, the first on-fixed period T1v is longer than the first on-fixed period T1u and the first on-fixed period T1w. Therefore, as shown in FIG. 60B , the switching loss of the V-phase first semiconductor switching element Vp (H (high side)) is smaller than that of the U-phase and W-phase.

In the waveform example 40, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in the waveform example 40, the second on-fixed period T2u is 90 degrees, while the second on-fixed period T2v is 60 degrees and the second on-fixed period T2w is 30 degrees. That is, in waveform example 40, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 60B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 60A and 60B , in waveform example 40, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In the waveform example 40, heat generation of the V-phase first semiconductor switching element Vp and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in waveform example 40, as shown in FIG. 60B , the U-phase first semiconductor switching element Up, the V-phase second semiconductor switching element Vn, the W-phase first semiconductor switching element Wp, and the W-phase The heat generation of the second semiconductor switching element Wn.

Waveform example 41 will be described with reference to FIGS. 61A and 61B . FIG. 61A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 61B is a graph showing switching loss.

As shown in FIG. 61A , the waveform example 41 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 41 has the following waveforms, that is, when the electrical angle is 0 degrees to 30 degrees, the electrical angle is 60 degrees to 120 degrees, the electrical angle is 150 degrees to 210 degrees, and the electrical angle is The output of any phase is fixed at 1 within the electrical angle of 330 degrees to 360 degrees. In addition, waveform example 41 is a waveform such that any electrical angle is within an electrical angle of 30 degrees to 60 degrees, an electrical angle of 120 degrees to 150 degrees, and an electrical angle of 210 degrees to 330 degrees. The phase output is fixed at 0. In waveform example 41, the electrical angle is 0 to 30 degrees, the electrical angle is 60 to 120 degrees, the electrical angle is 150 to 210 degrees, and the electrical angle is 330 to 330 degrees. 360 degrees is the high-side ON application period T3. In addition, in waveform example 41, the electrical angle of 30 degrees to 60 degrees, the electrical angle of 120 degrees to 150 degrees, and the electrical angle of 210 degrees to 330 degrees are low-side ON application periods. T4.

In the waveform example 41, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 41, the first on-fixed period T1u is from an electrical angle of 60 degrees to an electrical angle of 120 degrees. In waveform example 41, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 210 degrees. In waveform example 41, the electrical angle of 0° to 30° and the electrical angle of 330° to 360° are the first on-fixed periods T1w.

In the waveform example 41, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 41, the second on-fixed period T2u is from an electrical angle of 210 degrees to an electrical angle of 330 degrees. In waveform example 41, the electrical angle of 30° to 60° is the second on-fixed period T2v. In waveform example 41, the second on-fixed period T2w is from an electrical angle of 120 degrees to an electrical angle of 150 degrees.

In the waveform example 41, the first on-fixed period T1u is the same as the first on-fixed period T1v and the first on-fixed period T1w. In detail, in waveform example 41, the first on-fixed period T1u, the first on-fixed period T1v, and the first on-fixed period T1w are 60 degrees.

In waveform example 41, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in the waveform example 41, the second on-fixed period T2u is 120 degrees, whereas the second on-fixed period T2v and the second on-fixed period T2w are 30 degrees. That is, in waveform example 41, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 61B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 61A and 61B , in waveform example 41, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In the waveform example 41, the heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in waveform example 41, as shown in FIG. 61B , the V-phase first semiconductor switching element Vp, the V-phase second semiconductor switching element Vn, the W-phase first semiconductor switching element Wp, and the W-phase The heat generation of the second semiconductor switching element Wn.

Waveform example 42 will be described with reference to FIGS. 62A and 62B . FIG. 62A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 62B is a graph showing switching loss.

As shown in FIG. 62A, the waveform example 42 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 42 has the following waveforms, that is, within the electrical angle of 75 degrees to 105 degrees, the electrical angle of 150 degrees to 270 degrees, and the electrical angle of 330 degrees to 360 degrees, any The output of one phase is fixed at 1. In addition, the waveform example 42 is a waveform such that any electrical angle is within an electrical angle of 0° to 75°, an electrical angle of 105° to 150°, and an electrical angle of 270° to 330°. The phase output is fixed at 0. In waveform example 42, the high-side ON application period T3 is the electrical angle of 75 degrees to 105 degrees, the electrical angle of 150 degrees to 270 degrees, and the electrical angle of 330 degrees to 360 degrees. In addition, in waveform example 42, the electrical angle of 0° to 75°, the electrical angle of 105° to 150°, and the electrical angle of 270° to 330° are low-side ON application periods. T4.

In the waveform example 42, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In the waveform example 42, the first on-fixed period T1u is from an electrical angle of 75 degrees to an electrical angle of 105 degrees. In waveform example 42, an electrical angle of 150 degrees to an electrical angle of 270 degrees is the first on-fixed period T1v. In waveform example 42, an electrical angle of 330 degrees to an electrical angle of 360 degrees is the first on-fixed period T1w.

In the waveform example 42, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In the waveform example 42, the second on-fixed period T2u is from an electrical angle of 270 degrees to an electrical angle of 330 degrees. In waveform example 42, the second on-fixed period T2v is the electrical angle from 0° to 75°. In the waveform example 42, the electrical angle of 105° to 150° is the second on-fixed period T2w.

In the waveform example 42, in the V phase among the three phases, the first on-fixed period T1v is different from the first on-fixed period T1u and the first on-fixed period T1w. Specifically, in the waveform example 42, the first on-fixed period T1v is 120 degrees, whereas the first on-fixed period T1u and the first on-fixed period T1w are 30 degrees. That is, in the waveform example 42, the first on-fixed period T1v is longer than the first on-fixed period T1u and the first on-fixed period T1w. Therefore, as shown in FIG. 62B , the switching loss of the V-phase first semiconductor switching element Up (H (high side)) is smaller than that of the U-phase and W-phase.

In the waveform example 42, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in the waveform example 42, the second on-fixed period T2v is 75 degrees, while the second on-fixed period T2u is 60 degrees, and the second on-fixed period T2w is 45 degrees. That is, in waveform example 42, the second on-fixed period T2v is longer than the second on-fixed period T2u and the second on-fixed period T2w. Therefore, as shown in FIG. 62B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the U phase and the W phase.

As described above with reference to FIGS. 62A and 62B , in waveform example 42, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In the waveform example 42, heat generation of the V-phase first semiconductor switching element Vp and the V-phase second semiconductor switching element Vn can be simultaneously suppressed.

In addition, in waveform example 42, as shown in FIG. 62B , the U-phase first semiconductor switching element Up, the U-phase second semiconductor switching element Un, the W-phase first semiconductor switching element Wp, and the W-phase The heat generation of the second semiconductor switching element Wn.

Waveform example 43 will be described with reference to FIGS. 63A and 63B . FIG. 63A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 63B is a graph showing switching loss.

As shown in FIG. 63A, waveform example 43 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 43 has the following waveforms, that is, when the electrical angle is 0 degrees to 30 degrees, the electrical angle is 75 degrees to 105 degrees, the electrical angle is 150 degrees to 240 degrees, and the electrical angle is The output of any phase is fixed at 1 within the electrical angle of 330 degrees to 360 degrees. In addition, waveform example 43 is a waveform such that any electrical angle is within an electrical angle of 30 degrees to 75 degrees, an electrical angle of 105 degrees to 150 degrees, and an electrical angle of 240 degrees to 330 degrees. The phase output is fixed at 0. In waveform example 43, the electrical angle is 0 to 30 degrees, the electrical angle is 75 to 105 degrees, the electrical angle is 150 to 240 degrees, and the electrical angle is 330 to 330 degrees. 360 degrees is the high-side ON application period T3. In addition, in waveform example 43, the electrical angle is 30 degrees to 75 degrees, the electrical angle is 105 degrees to 150 degrees, and the electrical angle is 240 degrees to 330 degrees. T4.

In waveform example 43, the first on-fixed period T1 includes a first on-fixed period T1u, a first on-fixed period T1v, and a first on-fixed period T1w. In waveform example 43, the first on-fixed period T1u is from an electrical angle of 75 degrees to an electrical angle of 105 degrees. In waveform example 43, the electrical angle of 150° to 240° is the first on-fixed period T1v. In the waveform example 43, the electrical angle of 0 degrees to the electrical angle of 30 degrees and the electrical angle of 330 degrees to the electrical angle of 360 degrees are the first ON fixed period T1w.

In waveform example 43, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 43, the second on-fixed period T2u is from an electrical angle of 240 degrees to an electrical angle of 330 degrees. In waveform example 43, the second on-fixed period T2v is from an electrical angle of 30 degrees to an electrical angle of 75 degrees. In waveform example 43, the electrical angle of 105° to 150° is the second on-fixed period T2w.

In the waveform example 43, in the V phase among the three phases, the first on-fixed period T1v is different from the first on-fixed period T1u and the first on-fixed period T1w. Specifically, in waveform example 43, the first on-fixed period T1v is 90 degrees, while the first on-fixed period T1u is 30 degrees, and the first on-fixed period T1w is 60 degrees. That is, in waveform example 43, the first on-fixed period T1v is longer than the first on-fixed period T1u and the first on-fixed period T1w. Therefore, as shown in FIG. 63B , the switching loss of the V-phase first semiconductor switching element Vp (H (high side)) is smaller than that of the U-phase and W-phase.

In waveform example 43, the second on-fixed period T2u is different from the second on-fixed period T2v and the second on-fixed period T2w. Specifically, in waveform example 43, the second on-fixed period T2u is 90 degrees, whereas the second on-fixed period T2v and the second on-fixed period T2w are 45 degrees. That is, in waveform example 43, the second on-fixed period T2u is longer than the second on-fixed period T2v and the second on-fixed period T2w. Therefore, as shown in FIG. 63B , the switching loss of the second semiconductor switching element Un (L (low side)) of the U phase is smaller than that of the V phase and the W phase.

As described above with reference to FIGS. 63A and 63B , in waveform example 43, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In the waveform example 43, heat generation of the V-phase first semiconductor switching element Vp and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in waveform example 43, as shown in FIG. 63B , the U-phase first semiconductor switching element Up, the V-phase second semiconductor switching element Vn, the W-phase first semiconductor switching element Wp, and the W-phase The heat generation of the second semiconductor switching element Wn.

Waveform example 44 will be described with reference to FIGS. 64A and 64B . FIG. 64A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 64B is a graph showing switching loss.

As shown in FIG. 64A, the waveform example 44 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 44 is a waveform as follows, that is, any electrical angle is within an electrical angle of 0 degrees to an electrical angle of 30 degrees, an electrical angle of 150 degrees to an electrical angle of 270 degrees, and an electrical angle of 330 degrees to an electrical angle of 360 degrees. The output of one phase is fixed at 1. In addition, waveform example 44 is a waveform in which the output of any one phase is fixed at 0 within an electrical angle of 30 degrees to 150 degrees and an electrical angle of 270 degrees to 330 degrees. In waveform example 44, the high-side ON application period T3 is the electrical angle of 0° to 30°, the electrical angle of 150° to 270°, and the electrical angle of 330° to 360°. In addition, in waveform example 44, the low-side ON application period T4 is the electrical angle of 30 degrees to the electrical angle of 150 degrees and the electrical angle of 270 degrees to the electrical angle of 330 degrees.

In the waveform example 44, the first on-fixed period T1 includes a first on-fixed period T1v and a first on-fixed period T1w. In the waveform example 44, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 270 degrees. In the waveform example 44, the electrical angle of 0 degrees to the electrical angle of 30 degrees and the electrical angle of 330 degrees to the electrical angle of 360 degrees are the first ON fixed period T1w.

In waveform example 44, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 44, the second on-fixed period T2u is from an electrical angle of 270 degrees to an electrical angle of 330 degrees. In the waveform example 44, the electrical angle of 30 degrees to 90 degrees is the second on-fixed period T2v. In waveform example 44, the second on-fixed period T2w is from an electrical angle of 90 degrees to an electrical angle of 150 degrees.

In the waveform example 44, in the U phase of the three phases, the first on-fixed period T1v is different from the first on-fixed period T1u and the first on-fixed period T1w. Specifically, in waveform example 44, the first on-fixed period T1v is 120 degrees, whereas the first on-fixed period T1u is absent, and the first on-fixed period T1w is 60 degrees. That is, in waveform example 44, the first on-fixed period T1v is longer than the first on-fixed period T1u and the first on-fixed period T1w. Therefore, as shown in FIG. 64B , the switching loss of the V-phase first semiconductor switching element Vp (H (high side)) is smaller than that of the U-phase and W-phase.

In waveform example 44, the second on-fixed period T2u, the second on-fixed period T2v, and the second on-fixed period T2w are the same. In detail, in waveform example 44, the second on-fixed interval T2u, the second on-fixed interval T2v, and the second on-fixed period T2w are 60 degrees.

As described above with reference to FIGS. 64A and 64B , in waveform example 44, as in waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 44, the heat generation of the V-phase first semiconductor switching element Vp and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in the waveform example 44, as shown in FIG. 64B , the heat generation of the V-phase second semiconductor switching element Vn, the W-phase first semiconductor switching element Wp, and the W-phase second semiconductor switching element Wn can be simultaneously suppressed.

Waveform example 45 will be described with reference to FIGS. 65A and 65B . FIG. 65A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 65B is a graph showing switching loss.

As shown in Fig. 65A, waveform example 45 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, the waveform example 45 is a waveform as follows, that is, any electrical angle within the electrical angle of 0 degrees to 30 degrees, the electrical angle of 150 degrees to 240 degrees, and the electrical angle of 300 degrees to 360 degrees. The output of one phase is fixed at 1. In addition, waveform example 45 is a waveform in which the output of any one phase is fixed at 0 within an electrical angle of 30 degrees to 150 degrees, and an electrical angle of 240 degrees to 300 degrees. In waveform example 45, the high-side ON application period T3 is the electrical angle of 0° to 30°, the electrical angle of 150° to 240°, and the electrical angle of 300° to 360°. In addition, in waveform example 45, the low-side ON application period T4 is the electrical angle of 30 degrees to the electrical angle of 150 degrees and the electrical angle of 240 degrees to the electrical angle of 300 degrees.

In waveform example 45, the first on-fixed period T1 includes a first on-fixed period T1v and a first on-fixed period T1w. In waveform example 45, the electrical angle of 150° to 240° is the first on-fixed period T1v. In the waveform example 45, the electrical angle of 0° to 30° and the electrical angle of 300° to 360° are the first ON fixed period T1w.

In waveform example 45, the second on-fixed period T2 includes a second on-fixed period T2u, a second on-fixed period T2v, and a second on-fixed period T2w. In waveform example 45, the second on-fixed period T2u is from an electrical angle of 240 degrees to an electrical angle of 300 degrees. In the waveform example 45, the second on-fixed period T2v is from an electrical angle of 30 degrees to an electrical angle of 90 degrees. In waveform example 45, the second on-fixed period T2w is from an electrical angle of 90 degrees to an electrical angle of 150 degrees.

In waveform example 45, in the V phase among the three phases, the first on-fixed period T1v is different from the first on-fixed period T1u and the first on-fixed period T1w. Specifically, in waveform example 45, the first on-fixed period T1v is 90 degrees, whereas the first on-fixed period T1u does not exist. That is, in waveform example 45, the first on-fixed period T1v is longer than the first on-fixed period T1u. In addition, the first on-fixed period T1w is the same as the first on-fixed period T1v. Therefore, as shown in FIG. 65B , the switching loss of the first semiconductor switching element Up (H (high side)) of the V phase is smaller than that of the W phase.

In waveform example 45, the second on-fixed period T2u, the second on-fixed period T2v, and the second on-fixed period T2w are the same. In detail, in waveform example 45, the second on-fixed interval T2u, the second on-fixed interval T2v, and the second on-fixed period T2w are 60 degrees.

As described above with reference to FIGS. 65A and 65B , in waveform example 45, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 45, the heat generation of the V-phase first semiconductor switching element Vp and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

In addition, in the waveform example 45, as shown in FIG. 65B , the heat generation of the V-phase second semiconductor switching element Vn, the W-phase first semiconductor switching element Wp, and the W-phase second semiconductor switching element Wn can be simultaneously suppressed.

Waveform example 46 will be described with reference to FIGS. 66A and 66B . FIG. 66A is a graph showing output voltage Vu, output voltage Vv, and output voltage Vw. FIG. 66B is a graph showing switching loss.

As shown in FIG. 66A, the waveform example 46 is the following waveform, that is, according to the electrical angle, the output voltage of any phase in a certain electrical angle interval is fixed at 1, and the output voltage of any phase in another electrical angle interval is fixed at 0 . In detail, waveform example 46 is a waveform in which the output of any one phase is fixed at 1 within an electrical angle of 90 degrees to 270 degrees. In addition, the waveform example 46 is a waveform in which the output of any phase is fixed at 0 within the electrical angle of 0° to 90° and the electrical angle of 270° to 360°. In waveform example 46, the high-side ON application period T3 is from an electrical angle of 90 degrees to an electrical angle of 270 degrees. In addition, in the waveform example 46, the low-side ON application period T4 is the electrical angle of 0 degrees to the electrical angle of 90 degrees and the electrical angle of 270 degrees to the electrical angle of 360 degrees.

In the waveform example 46, the first on-fixed period T1 includes a first on-fixed period T1u and a first on-fixed period T1v. In waveform example 46, the first on-fixed period T1u is from an electrical angle of 90 degrees to an electrical angle of 150 degrees. In waveform example 46, the first on-fixed period T1v is from an electrical angle of 150 degrees to an electrical angle of 270 degrees.

In the waveform example 46, the second on-fixed period T2 includes a second on-fixed period T2u and a second on-fixed period T2v. In waveform example 46, the second on-fixed period T2u is from an electrical angle of 270 degrees to an electrical angle of 330 degrees. In the waveform example 46, the electrical angle of 0° to 90° and the electrical angle of 330° to 360° are the second on-fixed period T2v.

In waveform example 46, in the V phase among the three phases, the first on-fixed period T1v is different from the first on-fixed period T1u and the first on-fixed period T1w. In detail, in waveform example 46, the first on-fixed period T1v is 120 degrees, whereas the first on-fixed period T1u is 60 degrees, and there is no first on-fixed period T1w. That is, in waveform example 46, the first on-fixed period T1v is longer than the first on-fixed period T1u and the first on-fixed period T1w. Therefore, as shown in FIG. 66B , the switching loss of the V-phase first semiconductor switching element Vp (H (high side)) is smaller than that of the U-phase and W-phase.

In waveform example 46, the second on-fixed period T2v is different from the second on-fixed period T2u and the second on-fixed period T2w. Specifically, in waveform example 46, the second fixed ON period T2v is 120 degrees, whereas the second fixed ON period T2u is 60 degrees, and there is no second fixed ON period T2w. That is, in waveform example 46, the second on-fixed period T2v is longer than the second on-fixed period T2u and the second on-fixed period T2w. Therefore, as shown in FIG. 66B , the switching loss of the second semiconductor switching element Vn (L (low side)) of the V phase is smaller than that of the U phase and the W phase.

As described above with reference to FIGS. 66A and 66B , in waveform example 46, similarly to waveform example 1, by simultaneously suppressing the heat generation of the first semiconductor switching element of a certain phase and the second semiconductor switching element of a certain phase, It can suppress the temperature rise of the power converter (inverter) and improve the reliability. In waveform example 46, the heat generation of the V-phase first semiconductor switching element Vp and the V-phase second semiconductor switching element Vn can be simultaneously suppressed.

In addition, in waveform example 46, as shown in FIG. 66B , heat generation of the U-phase first semiconductor switching element Up and the U-phase second semiconductor switching element Un can be simultaneously suppressed.

The embodiments of the present invention have been described above with reference to the drawings ( FIGS. 1 to 66B ). However, the present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the gist thereof. For ease of understanding, the drawings schematically show the main body of each structural element, and for the convenience of drawing, the thickness, length, number, etc. of each structural element shown in the illustration are different from the actual ones. In addition, the material, shape, dimension, etc. of each component shown in the said embodiment are an example and are not specifically limited, Various changes can be made in the range which does not substantially deviate from the effect of this invention.

The motor drive circuit 100 (power converter) described with reference to FIGS. 1 to 66B outputs a three-phase AC output, but the present invention is not limited thereto. For example, the motor drive circuit 100 may output AC outputs of five or more phases. For example, the motor drive circuit 100 may output a five-phase AC output, thereby driving a five-phase motor M.

Industrial availability The invention can be ideally applied to power converters and motor modules.

20, 21u, 21v, 21w, 22u, 22v, 22w: temperature sensor 100: Motor drive circuit (power converter) 102, 102u, 102v, 102w: output terminals 110: Inverter Department 112, 112u, 112v, 112w: series body 114, 114u, 114v, 114w: connection points 120: Signal Generation Department 122: Carrier generation unit 124: Voltage command value generator 126: Comparative Department 200:Motor module B: DC voltage source C: Capacitor D: rectifier element M: motor N: Second power supply terminal P: first power terminal T1, T1u, T1v, T1w: first ON fixed period T2, T2u, T2v, T2w: 2nd ON fixed period T3: during high-side ON application T4: during low-side ON application Up, Vp, Wp: first semiconductor switching element Un, Vn, Wn: the second semiconductor switching element V1: first voltage V2: second voltage Vu, Vv, Vw: output voltage Iu, Iv, Iw: output current

FIG. 1 is a block diagram of a motor module according to an embodiment of the present invention. FIG. 2 is a circuit diagram showing an inverter unit. FIG. 3A is a graph showing output voltages. FIG. 3B is a graph showing switching loss. FIG. 4 is a table showing the relationship between waveform examples and switching loss. FIG. 5A is a graph showing output voltages. FIG. 5B is a graph showing switching loss. FIG. 6A is a graph showing output voltages. FIG. 6B is a graph showing switching loss. FIG. 7A is a graph showing output voltages. FIG. 7B is a graph showing switching loss. FIG. 8A is a graph showing output voltages. FIG. 8B is a graph showing switching loss. FIG. 9A is a graph showing output voltages. FIG. 9B is a graph showing switching loss. FIG. 10A is a graph showing output voltages. FIG. 10B is a graph showing switching loss. FIG. 11A is a graph showing output voltages. FIG. 11B is a graph showing switching loss. FIG. 12A is a graph showing output voltages. FIG. 12B is a graph showing switching loss. FIG. 13A is a graph showing output voltages. FIG. 13B is a graph showing switching loss. FIG. 14A is a graph showing output voltages. FIG. 14B is a graph showing switching loss. FIG. 15A is a graph showing output voltages. FIG. 15B is a graph showing switching loss. FIG. 16 is a graph showing switching loss. FIG. 17 is a diagram for explaining switching of UH_UL guard waveforms. FIG. 18 is a diagram for explaining switching of UH_UL guard waveforms. FIG. 19 is a graph showing switching loss. FIG. 20 is a diagram for explaining switching of UH_UL guard waveforms. FIG. 21 is a flowchart showing a method of switching guard waveforms. FIG. 22 is a flowchart showing a method of switching guard waveforms. FIG. 23 is a diagram showing a method of switching guard waveforms. FIG. 24 is a diagram showing a method of switching guard waveforms. FIG. 25 is a table showing the relationship between waveform examples and switching loss. FIG. 26A is a graph showing output voltages. FIG. 26B is a graph showing switching loss. Fig. 27A is a graph showing output voltages. FIG. 27B is a graph showing switching loss. FIG. 28A is a graph showing output voltages. FIG. 28B is a graph showing switching loss. Fig. 29A is a graph showing the output voltage. FIG. 29B is a graph showing switching loss. Fig. 30A is a graph showing the output voltage. FIG. 30B is a graph showing switching loss. FIG. 31A is a graph showing output voltages. FIG. 31B is a graph showing switching loss. Fig. 32A is a graph showing the output voltage. FIG. 32B is a graph showing switching loss. Fig. 33A is a graph showing output voltages. FIG. 33B is a graph showing switching loss. Fig. 34A is a graph showing the output voltage. FIG. 34B is a graph showing switching loss. Figure 35A is a graph showing the output voltage FIG. 35B is a graph showing switching loss. Fig. 36A is a graph showing the output voltage. FIG. 36B is a graph showing switching loss. Fig. 37A is a graph showing the output voltage. FIG. 37B is a graph showing switching loss. Fig. 38A is a graph showing the output voltage. FIG. 38B is a graph showing switching loss. Fig. 39A is a graph showing the output voltage. FIG. 39B is a graph showing switching loss. Fig. 40A is a graph showing the output voltage. FIG. 40B is a graph showing switching loss. Fig. 41A is a graph showing the output voltage. FIG. 41B is a graph showing switching loss. Fig. 42A is a graph showing the output voltage. FIG. 42B is a graph showing switching loss. Fig. 43 is a graph showing switching loss. FIG. 44 is a diagram for explaining switching of UH_VL protection waveforms. FIG. 45 is a diagram for explaining switching of UH_VL protection waveforms. FIG. 46 is a diagram for explaining switching of UH_VL protection waveforms. Fig. 47 is a flowchart showing a method of switching guard waveforms. Fig. 48 is a diagram showing a method of switching guard waveforms. FIG. 49 is a diagram showing a method of switching guard waveforms. FIG. 50A is a graph showing the output voltage. FIG. 50B is a graph showing switching loss. Fig. 51A is a graph showing the output voltage. FIG. 51B is a graph showing switching loss. Fig. 52A is a graph showing the output voltage. FIG. 52B is a graph showing switching loss. Fig. 53A is a graph showing the output voltage. FIG. 53B is a graph showing switching loss. Fig. 54A is a graph showing the output voltage. FIG. 54B is a graph showing switching loss. Fig. 55A is a graph showing the output voltage. FIG. 55B is a graph showing switching loss. Fig. 56A is a graph showing the output voltage. FIG. 56B is a graph showing switching loss. Fig. 57A is a graph showing the output voltage. FIG. 57B is a graph showing switching loss. Fig. 58A is a graph showing the output voltage. FIG. 58B is a graph showing switching loss. Fig. 59A is a graph showing the output voltage. FIG. 59B is a graph showing switching loss. Fig. 60A is a graph showing the output voltage. FIG. 60B is a graph showing switching loss. Fig. 61A is a graph showing the output voltage. FIG. 61B is a graph showing switching loss. Fig. 62A is a graph showing the output voltage. FIG. 62B is a graph showing switching loss. Fig. 63A is a graph showing the output voltage. FIG. 63B is a graph showing switching loss. Fig. 64A is a graph showing the output voltage. FIG. 64B is a graph showing switching loss. Fig. 65A is a graph showing the output voltage. FIG. 65B is a graph showing switching loss. Fig. 66A is a graph showing the output voltage. FIG. 66B is a graph showing switching loss.

100: Motor drive circuit (power converter)

102, 102u, 102v, 102w: output terminals

110: Inverter Department

120: Signal Generation Department

122: Carrier generation unit

124: Voltage command value generator

126: Comparative Department

200:Motor module

M: motor

Vu, Vv, Vw: output voltage

Iu, Iv, Iw: output current

Claims (14)

A power converter that converts direct current to n-phase alternating current, comprising: n output terminals, where the n output terminals output n-phase output voltages and n-phase output currents; a first power terminal, a first voltage is applied to the first power terminal; a second power terminal to which a second voltage lower than the first voltage is applied; and n series bodies, the n series bodies are connected in series with two semiconductor switching elements, n is the phase number of the AC output, which is an odd number of 3 or more, The n serial bodies are connected in parallel with each other, One end of each of the n series bodies is connected to the first power supply terminal, and the other end is connected to the second power supply terminal, The n series bodies respectively have a first semiconductor switching element and a second semiconductor switching element, the first semiconductor switching element is connected to the first power supply terminal, the second semiconductor switching element is connected to the second power supply terminal, the first semiconductor switching element and the second semiconductor switching element are connected at a connection point, The respective connection points of the n serial bodies are connected to the n output terminals, the first semiconductor switching element is switched between on and off at a frequency higher than that of the AC output, the second semiconductor switching element is switched between on and off at a frequency higher than that of the AC output, It has a protection action mode, and in the protection action mode, during one period of the n-phase AC output, at least one phase of the AC output has a period of the first fixed period and the second fixed period. At least one of the first semiconductor switching elements is fixed to be turned on during the first fixed on period, and the second semiconductor switch element is fixed to be turned on during the second fixed period of on, In the protection action mode, in at least one of the n phases, the first on-fixed period is different from the first on-fixed period of any other phase, or the second on-fixed period The period is different from the second on-fixed period of any other phase. The power converter as claimed in claim 1, wherein, having a plurality of operation modes with different PWM duty ratio waveforms, and having a function of switching the plurality of operation modes during power conversion, At least one of the plurality of operation modes is the protection operation mode. The power converter as claimed in claim 2, wherein, The protection action mode has multiple protection action modes, In the plurality of protection operation modes, during one cycle of the AC output, the ratio of each phase to at least one of the first on-fixed period and the second on-fixed period different. The power converter as claimed in claim 3, wherein, Switching between the plurality of protection operation modes and the plurality of protection operation modes is performed based on temperature information of at least one of the first semiconductor switching element and the second semiconductor switching element. The power converter as claimed in claim 3 or 4, wherein, The protective action mode has at least four protective action modes. The power converter according to any one of claims 1 to 4, wherein, One cycle of the AC output is divided into multiple periods, The plurality of periods are the first on-fixed period of any phase or the second on-fixed period of any phase, respectively. The power converter according to any one of claims 1 to 4, wherein, The first on-fixed period of any phase is longer than the first on-fixed period of other phases, and the second on-fixed period of any phase is longer than the second on-fixed period of other phases The period is long. The power converter as claimed in claim 7, wherein, The first on-fixed period and the second on-fixed period of the phase in which the first on-fixed period is longer than the first on-fixed period of the other phase are longer than the first on-fixed period of the other phase The second on-fixed period of the phase with the two longer on-fixed periods is longer than π/n and 2π/n or less. The power converter as claimed in claim 8, wherein, The first on-fixed period and the second on-fixed period of the phase in which the first on-fixed period is longer than the first on-fixed period of the other phase are longer than the first on-fixed period of the other phase The second on-fixed period of the phase with the longer on-on fixed period is both 2π/n, and the first on-fixed period is longer than the first on-fixed period of the other phase The first on-fixed period and the second on-fixed period of the phase longer than the second on-fixed period of the other phase are discontinuous with each other. The power converter according to any one of claims 1 to 4, 8, wherein, In two of the n phases, the first on-fixed period of one phase and the second on-fixed period of the other phase are continuous with each other, the first on-fixed period of the one phase and the The total of the second on-fixed periods of the other phase is 3π/n. The power converter of claim 10, wherein, The first on-fixed period of the one phase and the second on-fixed period of the other phase are 3π/(2n), respectively. The power converter according to any one of claims 3, 4, 8, and 9, which converts direct current into n-phase alternating current, wherein, The protection action mode includes a first selection protection action mode, In the first selection protection action mode, the first semiconductor switching element and the second semiconductor switching element of one phase are protected, The first selective protection action mode includes a plurality of k protection action modes, and in the plurality of k protection action modes, the first semiconductor switching element and the second semiconductor switch of a phase other than one phase Among the elements, k number of the first semiconductor switching elements or the second semiconductor switching elements are protected, wherein k is a natural number below 2n-3, The selection of the k protection action modes is performed based on the temperature information. The power converter according to any one of claims 3, 4, 8, 11, wherein, The protection action mode includes a second selection protection action mode, In the second selection protection action mode, the first semiconductor switching element of one phase and the second semiconductor switching element of other phases are protected, the first on-fixed period of the one phase is continuous with the second on-fixed period of the other phase, The second selective protection action mode includes a plurality of k protection action modes, and in the plurality of k protection action modes, all the first semiconductor switching elements except the one phase and the other phases Among the first semiconductor switching elements and the second semiconductor switching elements other than the second semiconductor switching element, k pieces of the first semiconductor switching elements or the second semiconductor switching elements are protected, and based on the temperature Information is used to select the k protection action modes, wherein k is a natural number below 2n-3. A motor module, comprising: A power converter according to any one of claims 1 to 4, 8, 9, 11; and a motor input with the output of the power converter.

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