JP2021090338A - Rotary machine control device and control method - Google Patents

Abstract

To avoid destruction of an inverter element while suppressing generation of sudden fluctuations in torque.SOLUTION: A rotary machine control device 5 includes an inverter 10, a rotational position sensor RS for detecting a rotor position of a motor M1 and a control circuit 20. The control circuit 20 includes a first control section for applying a voltage to the motor M1 using the inverter 10, a second control section for applying a voltage to the moor M1 using the inverter 10 and a switching section for switching the first control section and the second control section so that a current or torque of the motor M1 follows a command current or command torque. The second control section executes: (i)driving the inverter so that a high-side switch and a low-side switch of a U-phase switching circuit become a non-conductive state over the whole of a first period of a U phase and (ii)driving the inverter so that either one of the high-side switch and the low-side switch of the U-phase switching circuit becomes a conductive state over a part or the whole of a second period of the U phase.SELECTED DRAWING: Figure 2

Description

The present invention relates to a rotary machine control device and a control method.

Vehicles are being electrified, such as EVs (Electric Vehicles), HEVs (Hybrid Electric Vehicles), PHVs (Plug-in Hybrid Vehicles), and FCVs (Fuel Cell Vehicles), due to fuel efficiency regulations and CO2 regulations. Further, in order to improve the electric efficiency of the vehicle, a permanent magnet synchronous motor is often used as a motor for driving the vehicle.

Permanent magnet synchronous motors are highly efficient because they do not require an exciting current, but the induced voltage generated by the field magnetic flux of the permanent magnet is proportional to the number of revolutions (also referred to as rotational speed or angular velocity in the following description). Then, when the number of revolutions exceeds a certain level, the induced voltage exceeds the output voltage of the inverter. Therefore, when the permanent magnet synchronous motor is rotated at high speed, weak magnetic flux control is performed to suppress the induced voltage generated by the field magnetic flux of the permanent magnet.

On the other hand, the switch element of the inverter may be destroyed by the large induced voltage generated by the rotation of the permanent magnet synchronous motor.

As a countermeasure, three-phase short-circuit control is performed in which the three phases of the permanent magnet synchronous motor are short-circuited and the voltage induced by the permanent magnet synchronous motor is set to almost 0 (zero). As an example of the three-phase short-circuit control, Patent Document 1 states that an inverter for driving a permanent magnet synchronous motor, an abnormality detection unit for detecting an abnormality such as an overvoltage generated in the inverter, and an inverter are in a state of three-phase short-circuit control. A vehicle drive with a three-phase short circuit for the purpose is described. In this vehicle drive device, when an abnormality is detected by the abnormality detection unit, the inverter is switched from the three-phase PWM (Pulse Width Modulation) control state to the three-phase short-circuit control state to reduce the overvoltage applied to the inverter. There is.

JP-A-2015-198503

However, there is a problem that a steep fluctuation of torque may occur when the inverter is switched from the state of three-phase PWM control to the state of three-phase short-circuit control.

Therefore, the present invention provides a rotary machine control device capable of avoiding destruction of inverter elements while suppressing the occurrence of sudden fluctuations in torque.

The rotary machine control device according to one aspect of the present invention detects an inverter for driving a three-phase rotary machine having a U-phase switching circuit, a V-phase switching circuit, and a W-phase switching circuit, and a rotor position of the three-phase rotary machine. The rotor position detector, the rotor position detector, and a control circuit electrically connected to the inverter are provided, and the control circuit includes a command current or a command for the current or torque of the three-phase rotating machine. A first control unit that applies a voltage to the three-phase rotating machine using the inverter, a second control unit that applies a voltage to the three-phase rotating machine using the inverter, and the above. The second control unit has a switching unit for switching between the first control unit and the second control unit, and the second control unit has (a) a rotor angle obtained from the rotor position detected by the rotor position detector. The period of ± 30 ° centered on the zero cross point of the induced voltage in the U phase of the phase rotator is the second period of the U phase, and the period sandwiched between the second periods of the adjacent U phases is the second period of the U phase. It is defined as one period, and (b) the period in which the rotor angle is ± 30 ° around the zero cross point of the induced voltage in the V phase of the three-phase rotating machine is defined as the second period of the V phase, and the adjacent said The period sandwiched between the second period of the V phase is defined as the first period of the V phase, and (c) the rotor angle is ± 30 centered on the zero cross point of the induced voltage in the W phase of the three-phase rotary machine. When the period of ° is defined as the second period of the W phase and the period sandwiched between the adjacent second periods of the W phase is defined as the first period of the W phase, the inverter is driven based on the rotor angle. By doing so, a voltage is applied to the three-phase rotating machine, and in driving the inverter, (i) the high-side switch and the low-side switch of the U-phase switching circuit are in a non-conducting state during the entire first period of the U-phase. Therefore, the high-side switch and the low-side switch of the V-phase switching circuit are in a non-conducting state during the entire first period of the V-phase, and the high-side of the W-phase switching circuit is in the entire period of the first period of the W-phase. The inverter is driven so that the switch and the low-side switch are in a non-conducting state, and (ii) the high-side switch and the high-side switch of the U-phase switching circuit in a part or all of the second period of the U-phase. One of the low-side switches becomes conductive, and the high-voltage inverter of the V-phase switching circuit is used for a part or all of the second period of the V-phase. Either the inverter switch or the low-side switch becomes conductive, and either the high-side switch or the low-side switch of the W-phase switching circuit becomes conductive during a part or all of the second period of the W phase. The inverter is driven so as to be.

It should be noted that these comprehensive or specific embodiments may be realized in a recording medium such as a system, method, integrated circuit, computer program or computer readable CD-ROM, system, method, integrated circuit, computer program. And any combination of recording media may be realized.

The rotary machine control device of the present invention can avoid the destruction of the inverter element while suppressing the occurrence of abrupt fluctuations in torque.

FIG. 1 is a schematic view illustrating an electric vehicle including a rotary machine control device according to the first embodiment. FIG. 2 is a circuit diagram illustrating the configuration of the rotary machine control device according to the first embodiment. FIG. 3 is a schematic view showing the configuration of the control circuit according to the first embodiment. FIG. 4 is a conceptual diagram illustrating the positional relationship between the rotor position and the coil in the first embodiment. FIG. 5 is an explanatory diagram showing the coordinate axes of the rotating machine and the rotor angle according to the first embodiment. FIG. 6 is an explanatory diagram showing a switching pattern in the second mode according to the first embodiment. FIG. 7 is an explanatory diagram showing a switching pattern in the third mode according to the first embodiment. FIG. 8 is a timing diagram showing switching patterns in the first mode and the second mode in the first embodiment. FIG. 9 is a circuit diagram showing a first example of the control circuit according to the first embodiment. FIG. 10 is a flow chart showing processing of a first example of the control circuit according to the first embodiment. FIG. 11 is a circuit diagram showing a second example of the control circuit according to the first embodiment. FIG. 12 is a flow chart showing processing of a second example of the control circuit according to the first embodiment. FIG. 13 is an explanatory diagram showing an example of temporal changes in torque, voltage, and current of a motor controlled by the rotary machine control device according to the first embodiment. FIG. 14 is a timing diagram showing switching patterns in the second mode and the third mode in the second embodiment. FIG. 15 is a circuit diagram showing an example of the control circuit according to the second embodiment. FIG. 16 is a flow chart showing the processing of the control circuit according to the second embodiment. FIG. 17 is an explanatory diagram showing a first example of temporal changes in torque, voltage, and current of a motor controlled by a rotary machine control device in Modification 1 of each embodiment. FIG. 18 is a flow chart showing the processing of the control circuit in the second modification of each embodiment. FIG. 19 is an explanatory diagram showing a second example of temporal changes in torque, voltage, and current of a motor controlled by a rotary machine control device in Modification 2 of each embodiment.

The rotary machine control device according to one aspect of the present invention detects an inverter for driving a three-phase rotary machine having a U-phase switching circuit, a V-phase switching circuit, and a W-phase switching circuit, and a rotor position of the three-phase rotary machine. The rotor position detector, the rotor position detector, and a control circuit electrically connected to the inverter are provided, and the control circuit includes a command current or a command for the current or torque of the three-phase rotating machine. A first control unit that applies a voltage to the three-phase rotating machine using the inverter, a second control unit that applies a voltage to the three-phase rotating machine using the inverter, and the above. The second control unit has a switching unit for switching between the first control unit and the second control unit, and the second control unit has (a) a rotor angle obtained from the rotor position detected by the rotor position detector. The period of ± 30 ° centered on the zero cross point of the induced voltage in the U phase of the phase rotator is the second period of the U phase, and the period sandwiched between the second periods of the adjacent U phases is the second period of the U phase. It is defined as one period, and (b) the period in which the rotor angle is ± 30 ° around the zero cross point of the induced voltage in the V phase of the three-phase rotating machine is defined as the second period of the V phase, and the adjacent said The period sandwiched between the second period of the V phase is defined as the first period of the V phase, and (c) the rotor angle is ± 30 centered on the zero cross point of the induced voltage in the W phase of the three-phase rotary machine. When the period of ° is defined as the second period of the W phase and the period sandwiched between the adjacent second periods of the W phase is defined as the first period of the W phase, the inverter is driven based on the rotor angle. By doing so, a voltage is applied to the three-phase rotating machine, and in driving the inverter, (i) the high-side switch and the low-side switch of the U-phase switching circuit are in a non-conducting state during the entire first period of the U-phase. Therefore, the high-side switch and the low-side switch of the V-phase switching circuit are in a non-conducting state during the entire first period of the V-phase, and the high-side of the W-phase switching circuit is in the entire period of the first period of the W-phase. The inverter is driven so that the switch and the low-side switch are in a non-conducting state, and (ii) the high-side switch and the high-side switch of the U-phase switching circuit in a part or all of the second period of the U-phase. One of the low-side switches becomes conductive, and the high-voltage of the V-phase switching circuit during a part or all of the second period of the V-phase. Either the inverter switch or the low-side switch becomes conductive, and either the high-side switch or the low-side switch of the W-phase switching circuit becomes conductive during a part or all of the second period of the W phase. The inverter is driven so as to be.

According to the above aspect, the rotary machine control device can suppress a steep fluctuation of torque by switching from the first control unit to the second control unit. The second control unit drives the inverter so that at least a part of the power generated by the three-phase rotating machine becomes reactive power, thereby generating braking force while suppressing an increase in the voltage of the DC bus part of the inverter. Let me. Further, the occurrence of abrupt fluctuations in torque is suppressed when switching from the first control unit to the second control unit. As a result, the rotary machine control device can avoid the destruction of the inverter element while suppressing the occurrence of abrupt fluctuations in torque.

For example, at least one of the second control unit and the switching unit may be configured by a logic circuit.

According to the above aspect, since at least one of the second control unit and the switching unit is composed of a logic circuit, the rotary machine control device has higher resistance to failure than the case where it is composed of an arithmetic unit or a processor. .. Therefore, the rotary machine control device can improve the resistance to failure and avoid the destruction of the inverter element while suppressing the occurrence of abrupt fluctuations in torque.

For example, in the switching unit, the circuit breaker electrically connected to the DC bus portion of the inverter becomes non-conducting, or the overvoltage detection signal is transmitted from the overvoltage detection circuit electrically connected to the DC bus portion. When it is output, the first control unit may be switched to the second control unit.

According to the above aspect, in principle, the rotary machine control device controls the three-phase rotary machine by the first control unit, and when the circuit breaker is disconnected or the overvoltage of the DC bus portion is actually detected, the first control device is used. (Ii) Switching to the control unit can be performed. As a result, the rotary machine control device can appropriately control the three-phase rotary machine by performing control by the first control unit at normal times and controlling by the second control unit as needed. As a result, the rotary machine control device performs control by the second control unit when control by the second control unit is required, thereby avoiding destruction of the inverter element while suppressing the occurrence of sudden fluctuations in torque. can do.

For example, in the control circuit, one of the high-side switch and the low-side switch in the U-phase switching circuit, the V-phase switching circuit, and the W-phase switching circuit is in a conductive state, and the other is in a non-conducting state. A third control unit that controls the inverter is further provided, and the switching unit switches with the third control unit in addition to the first control unit and the second control unit, and the switching unit is When the voltage in the DC bus unit exceeds a predetermined voltage, the second control unit may be switched to the third control unit.

According to the above aspect, the rotary machine control device can suppress the overvoltage from being applied to the inverter by controlling the three-phase rotary machine by the third control, that is, the three-phase short-circuit control. Further, the above-mentioned three-phase short-circuit control is performed when the overvoltage of the DC bus portion of the inverter is actually detected. As a result, even when the rotary machine control device is being controlled by the first control unit or the second control unit, the inverter is overvoltageed by being controlled by the third control unit as necessary. Can be suppressed. As a result, the rotary machine control device can avoid the destruction of the inverter element while suppressing the occurrence of abrupt fluctuations in torque by further using the three-phase short-circuit control.

For example, the switching unit calculates the rotation speed of the three-phase rotating machine based on the output from the rotor position detector when the third control unit is driving the inverter, and the calculated rotation speed. When the number becomes equal to or less than a predetermined rotation speed, the third control unit may be switched to the second control unit.

According to the above aspect, since the rotary machine control device switches from the third control unit to the second control unit when the rotation speed of the three-phase rotary machine is equal to or less than the predetermined rotation speed, in the third control, that is, the three-phase short circuit control. It is possible to suppress the load torque generated at low speed of the rotating machine and avoid the destruction of the inverter element.

For example, in the control circuit, one of the high-side switch and the low-side switch in the U-phase switching circuit, the V-phase switching circuit, and the W-phase switching circuit is in a conductive state, and the other is in a non-conducting state. A third control unit that controls the inverter is further provided, and the switching unit switches with the third control unit in addition to the first control unit and the second control unit, and the switching unit is , When the circuit breaker electrically connected to the DC bus portion of the inverter becomes non-conducting, or when the overvoltage detection signal is output from the overvoltage detection circuit electrically connected to the DC bus portion. The first control unit may be switched to the third control unit.

According to the above aspect, in principle, the rotary machine control device controls the three-phase rotary machine by the first control unit, and when the circuit breaker is disconnected or the overvoltage of the DC bus portion is actually detected, the first control device is used. (3) Switching to the control unit can be performed. As a result, the rotary machine control device can appropriately control the three-phase rotary machine by performing control by the first control unit at normal times and controlling by the third control unit as needed. As a result, the rotary machine control device can avoid the destruction of the inverter element by performing the control by the third control unit when the control by the third control unit is required.

For example, the switching unit calculates the rotation speed of the three-phase rotating machine based on the output from the rotor position detector when the third control unit is driving the inverter, and the calculated rotation speed. When the number becomes equal to or less than a predetermined rotation speed, the third control unit may be switched to the second control unit.

According to the above aspect, since the rotary machine control device switches from the third control unit to the second control unit when the rotation speed of the three-phase rotary machine is equal to or less than the predetermined rotation speed, in the third control, that is, the three-phase short circuit control. It is possible to suppress the load torque generated at low speed of the rotating machine and avoid the destruction of the inverter element.

For example, the third control unit may be composed of a logic circuit.

According to the above aspect, since the third control unit is composed of a logic circuit, the rotary machine control device has higher resistance to failure than the case where it is composed of an arithmetic unit or a processor. Therefore, the rotary machine control device can improve the resistance to failure and avoid the destruction of the inverter element while suppressing the occurrence of abrupt fluctuations in torque.

For example, the switching unit switches from the second control unit to the third control unit when the rotation speed is equal to or lower than the predetermined rotation speed and the voltage in the DC bus portion is equal to or higher than the predetermined voltage. You may.

According to the above aspect, the rotary machine control device can suppress the overvoltage from being applied to the inverter by controlling the three-phase rotary machine by the third control, that is, the three-phase short-circuit control. Further, the above-mentioned three-phase short-circuit control is performed when the voltage of the DC bus portion is equal to or higher than a predetermined voltage. As a result, even when the rotary machine control device is being controlled by the second control unit, it is possible to prevent the inverter from being overvoltageed by performing the control by the third control unit as necessary. As a result, the rotary machine control device can avoid the destruction of the inverter element while suppressing the occurrence of abrupt fluctuations in torque.

The control method according to one aspect of the present invention is a control method for a rotary machine control device, wherein the rotary machine control device has a U-phase switching circuit, a V-phase switching circuit, and a W-phase switching circuit. The control method includes an inverter that drives the inverter, a rotor position detector that detects the rotor position of the three-phase rotating machine, the rotor position detector, and a control circuit that is electrically connected to the inverter. The first control step of applying a voltage to the three-phase rotating machine using the inverter so that the current or torque of the three-phase rotating machine follows the command current or the command torque, and the above using the inverter. It has a second control step of applying a voltage to the three-phase rotary machine and a switching step of switching between the first control step and the second control step, and the second control step is (a) the rotor position detection. The period in which the rotor angle obtained from the rotor position detected by the device is ± 30 ° around the zero cross point of the induced voltage in the U phase of the three-phase rotary machine is defined as the second period of the U phase, and the adjacent said The period sandwiched between the second period of the U phase is defined as the first period of the U phase, and (b) the rotor angle is ± 30 centered on the zero cross point of the induced voltage in the V phase of the three-phase rotary machine. The period of ° is defined as the second period of the V phase, the period sandwiched between the second periods of the adjacent V phase is defined as the first period of the V phase, and (c) the rotor angle is the three-phase rotation. The period of ± 30 ° centered on the zero cross point of the induced voltage in the W phase of the machine is the second period of the W phase, and the period sandwiched between the second period of the adjacent W phase is the first period of the W phase. When the voltage is applied to the three-phase rotating machine by driving the inverter based on the rotor angle, in driving the inverter, (i) in the entire period of the first period of the U phase. The high-side switch and the low-side switch of the U-phase switching circuit are in a non-conducting state, and the high-side switch and the low-side switch of the V-phase switching circuit are in a non-conducting state during the entire first period of the V-phase. The inverter is driven so that the high-side switch and the low-side switch of the W-phase switching circuit are in a non-conducting state during the entire first period of the above, and (ii) a part of the second period of the U-phase. Alternatively, either the high-side switch or the low-side switch of the U-phase switching circuit becomes conductive during the entire period. In a part or all of the second period of the V phase, either the high side switch or the low side switch of the V phase switching circuit becomes conductive, and a part of the second period of the W phase or The inverter is driven so that either the high-side switch or the low-side switch of the W-phase switching circuit is in a conductive state during the entire period.

According to the above aspect, the same effect as that of the rotary machine control device is obtained.

For example, the control method further includes a third control step of applying a voltage to the three-phase rotator using the inverter, and the third control step includes the U-phase switching circuit and the V-phase switching circuit. The inverter may be driven so that one of the high-side switch and the low-side switch in the W-phase switching circuit is in a conductive state and the other is in a non-conducting state.

According to the above aspect, the same effect as that of the rotary machine control device is obtained.

It should be noted that these comprehensive or specific embodiments may be realized in a recording medium such as a system, method, integrated circuit, computer program or computer readable CD-ROM, system, method, integrated circuit, computer program. Alternatively, it may be realized by any combination of recording media.

Hereinafter, embodiments will be specifically described with reference to the drawings.

It should be noted that all of the embodiments described below show comprehensive or specific examples. Numerical values, shapes, materials, components, arrangement positions and connection forms of components, steps, order of steps, etc. shown in the following embodiments are examples, and are not intended to limit the present invention. Further, among the components in the following embodiments, the components not described in the independent claims indicating the highest level concept are described as arbitrary components.

It should be noted that each figure is a schematic view and is not necessarily exactly shown. Further, in each figure, substantially the same configuration is designated by the same reference numerals, and duplicate description may be omitted or simplified.

(Embodiment 1)
[1-1. Vehicle drive configuration]
First, the configuration of the rotary machine control device 5 according to the present embodiment will be described with reference to FIGS. 1 and 2.

FIG. 1 is a diagram illustrating an electric vehicle 1 including a rotary machine control device 5 according to the present embodiment. The electric vehicle 1 includes a drive wheel 2, a power transmission mechanism 3, a motor M1, an inverter 10, and a battery P1. Of these configurations, the rotary machine control device 5 is composed of a motor M1, an inverter 10, and a battery P1.

The motor M1 is a three-phase AC type permanent magnet synchronous motor that drives the drive wheels 2 of the electric vehicle 1, and is, for example, an embedded magnet synchronous motor or a surface magnet synchronous motor. The motor M1 corresponds to a three-phase rotating machine.

The power transmission mechanism 3 is composed of, for example, a differential gear and a drive shaft, and transmits power between the motor M1 and the drive wheels 2. The rotational force of the motor M1 is transmitted to the drive wheels 2 via the power transmission mechanism 3. Further, the rotational force of the drive wheels 2 is transmitted to the motor M1 via the power transmission mechanism 3. The electric vehicle 1 does not have to be provided with the power transmission mechanism 3, and may have a structure in which the motor M1 and the drive wheels 2 are directly connected.

The battery P1 is, for example, a DC power source such as a lithium ion battery. The battery P1 supplies and stores electric power for driving the motor M1.

The inverter 10 converts the DC power supplied from the battery P1 into, for example, three-phase AC power, and supplies the AC power to the motor M1. As described above, the rotary machine control device 5 is configured to drive the three-phase AC motor M1 by using the electric power of the battery P1.

FIG. 2 is a circuit diagram illustrating the configuration of the rotary machine control device 5.

As shown in FIG. 2, the rotary machine control device 5 includes a motor M1, an inverter 10, and a battery P1. The inverter 10 includes a three-phase bridge circuit 40, a drive circuit 30, and a control circuit 20.

Note that FIG. 2 also shows a smoothing capacitor C1 that smoothes the voltage applied to the three-phase bridge circuit 40, and a circuit breaker 32 that is electrically connected to the DC bus portion of the inverter 10. The voltage Vp shown in FIG. 2 is the power supply voltage, and the voltage Vg is the ground voltage.

The three-phase bridge circuit 40 is a circuit that converts the DC power supplied from the battery P1 into three-phase AC power by a switching operation, supplies the AC power to the motor M1, and drives the motor M1. The input side of the three-phase bridge circuit 40 for switching operation control is connected to the drive circuit 30, the power input side is connected to the battery P1, and the output side is connected to the motor M1.

The three-phase bridge circuit 40 is located on the switch elements (also referred to as high-side switches) S1, S2 and S3 provided in the upper arm group located on the upper side of the paper in FIG. 2 and on the lower side on the paper in FIG. It is provided with switch elements (also referred to as low-side switches) S4, S5 and S6 provided in the lower arm group. For example, the switch elements S1 to S6 are composed of a field effect transistor (FET), an insulated gate bipolar transistor (IGBT), or the like. Further, each of the switch elements S1 to S6 may be configured by using a wide bandgap semiconductor.

The switch elements S1, S2, and S3 are connected between the three terminals of the motor M1 (or the output line connected to these terminals) and the power supply line Lp connected to the positive electrode of the battery P1. The switch elements S4, S5 and S6 are connected between the above three terminals (or output lines) and the ground wire Lg connected to the negative electrode of the battery P1. Further, a freewheeling diode is connected in parallel to each of the switch elements S1 to S6. The freewheeling diode may be a parasitic diode parasitic on each switch element S1 to S6.

The switch elements S1 to S6 are connected to the drive circuit 30 and are driven by the control signal output from the drive circuit 30. The motor M1 is driven in a state of power running, regeneration, coasting, stopping, or the like based on the driving of the switch elements S1 to S6.

The drive circuit 30 outputs a signal for driving each of the switch elements S1 to S6 based on the signal from the control circuit 20.

The control circuit 20 is a circuit for controlling the application of a voltage to the motor M1 by using the inverter 10. The control circuit 20 includes a command current or a command torque acquired from an external device of the rotary machine control device 5, and current values iu, iv, and iwa obtained from the current sensors CSu, CSv, and CSw that detect the current flowing through the motor M1. , The rotor angle obtained from the rotation position sensor RS provided in the motor M1 is acquired, and the above control is performed. The rotation position sensor RS corresponds to a rotor position detector that detects the rotor position of the motor M1.

The configuration of the control circuit 20 will be described in detail with reference to FIG.

FIG. 3 is a schematic view showing the configuration of the control circuit 20 according to the present embodiment.

As shown in FIG. 3, the control circuit 20 includes a first control unit 21, a second control unit 22, a third control unit 23, and a switching unit 24.

The first control unit 21 is a control unit for controlling the application of a voltage to the motor M1 by using the inverter 10. The control by the first control unit 21 is also referred to as the first control. The state in which the motor M1 is driven by the signal output by the first control unit 21 is also referred to as the first mode.

Similarly, the second control unit 22 and the third control unit 23 are control units for controlling the application of voltage to the motor M1 by using the inverter 10, respectively. The control by the second control unit 22 and the third control unit 23 is also referred to as a second control and a third control, respectively. The state in which the motor M1 is driven by the signals output by the second control unit 22 and the third control unit 23 is also referred to as a second mode and a third mode, respectively.

The first control unit 21 controls to apply a voltage to the motor M1 by using the inverter 10 so that the current of the motor M1 follows the command current or the torque of the motor M1 follows the command torque. .. The first control unit 21 acquires the value of the command torque or the command current from an external device of the rotary machine control device 5, and also acquires the rotor angle θ from the motor M1. Then, the first control unit 21 performs the above control so as to follow the acquired command torque or command current according to the acquired rotor angle θ. Specifically, the first control unit 21 generates a voltage command from a current command or a torque command, as is generally performed in the past, and based on the voltage command, the inverter 10 causes the inverter 10 as described above. A signal (for example, a PWM signal) for three-phase PWM control that drives each switch element S1 to S6 so as to apply a voltage to the motor M1 is generated. Then, the first control unit 21 drives the inverter 10 by outputting the generated PWM signal to the inverter 10 via the switching unit 24. The PWM signals generated by the first control unit 21 are, for example, the signals UH, UL, VH, VL, WH and WL in the period of the first mode (section before time 0.3 seconds) of FIG. 8 described later. It has a waveform as shown. Here, the signals UH and UL correspond to the U-phase high-side switch (switch element S1) and the low-side switch (switch element S4), respectively. The signals VH and VL correspond to the V-phase high-side switch (switch element S2) and the low-side switch (switch element S5), respectively. The signals WH and WL correspond to the W-phase high-side switch (switch element S3) and low-side switch (switch element S6), respectively.

The second control unit 22 controls to apply a voltage to the motor M1 by using the inverter 10 so that at least a part of the electric power generated by the motor M1 becomes ineffective power. The second control unit 22 acquires a rotor angle θ from the motor M1 and drives the inverter 10 according to the acquired rotor angle θ as shown in (i) and (ii) below.

(I) In the second control unit 22, the high-side switch and the low-side switch of the U-phase switching circuit are in a non-conducting state during the entire period of the first period of the U-phase, and the V-phase switching is performed during the entire period of the first period of the V-phase. The inverter 10 is driven so that the high-side switch and the low-side switch of the circuit are in the non-conducting state, and the high-side switch and the low-side switch of the W-phase switching circuit are in the non-conducting state during the entire first period of the W phase.

(Ii) In the second control unit 22, either the high side switch or the low side switch of the U phase switching circuit becomes conductive during a part or the whole period of the second period of the U phase, and the second control unit 22 is in the second period of the V phase. Either the high-side switch or the low-side switch of the V-phase switching circuit becomes conductive during a part or the whole period, and the high-side switch of the W-phase switching circuit and the high-side switch of the W-phase switching circuit during a part or the whole period of the second period of the W phase. The inverter 10 is driven so that one of the low-side switches is in a conductive state.

Here, the first period and the second period of each phase are defined as follows (a), (b) and (c).

(A) The period in which the rotor angle θ is ± 30 ° around the zero cross point of the induced voltage in the U phase of the motor M1 is defined as the second period of the U phase, and is sandwiched between the second periods of the adjacent U phases. The period is defined as the first period of the U phase.

(B) The period in which the rotor angle θ is ± 30 ° around the zero cross point of the induced voltage in the V phase of the motor M1 is defined as the second period of the V phase, and is sandwiched between the second periods of the adjacent V phases. The period is defined as the first period of the V phase.

(C) The period in which the rotor angle θ is ± 30 ° centered on the zero cross point of the induced voltage in the W phase of the motor M1 is defined as the second period of the W phase, and is sandwiched between the second periods of the adjacent W phases. The period is defined as the first period of the W phase.

The second control unit 22 may be realized by a logic circuit or a microcomputer.

The third control unit 23 is an inverter 10 so that one of the high-side switch and the low-side switch in the U-phase switching circuit, the V-phase switching circuit, and the W-phase switching circuit is in a conductive state and the other is in a non-conducting state. To control. In other words, the third control unit 23 includes the switch elements (high side switches) S1, S2 and S3 of the arm group of the three-phase bridge circuit 40, and the switch elements (low side switches) S4, S5 and S6 of the lower arm group. Of these, each switch element of one arm group is short-circuited, and each switch element of the other arm group is opened (also referred to as three-phase short-circuit control). The third control unit 23 may be realized by a logic circuit or a microcomputer. Further, the third control unit 23 is not an essential configuration.

The switching unit 24 switches the control of driving the inverter 10. Specifically, the switching unit 24 switches between the first control unit 21 and the second control unit 22 as a control unit that controls the drive of the inverter 10. For example, the switching unit 24 switches between the first control unit 21 and the second control unit 22 when a predetermined abnormality is detected. The predetermined abnormality is, for example, that the circuit breaker 32 electrically connected to the DC bus portion of the inverter 10 has become non-conducting, and the overvoltage detection signal is output from the overvoltage detection circuit electrically connected to the DC bus portion. This includes the fact that the signal has been output, or that a signal indicating that an abnormal operation of various microcomputers mounted on the electric vehicle 1 has been detected has been output. The switching unit 24 receives a signal output when it is detected that the circuit breaker 32 electrically connected to the DC bus of the inverter 10 has become non-conducting, so that the circuit breaker 32 can be operated. It is possible to know that it has become non-conducting.

Further, when the control circuit 20 includes the third control unit 23, the switching unit 24 is added to the first control unit 21 and the second control unit 22 as control units for controlling the drive of the inverter 10. Alternatively, the third control unit 23 may be switched. For example, the switching unit 24 switches the control unit that controls the drive of the inverter 10 from the second control unit 22 to the third control unit 23 when the voltage in the DC bus unit exceeds a predetermined voltage.

The switching unit 24 may be realized by a logic circuit or may be realized by a microcomputer.

Hereinafter, the switching patterns in the second mode and the third mode will be described in detail.

(1) Second Mode FIG. 4 is a conceptual diagram illustrating a method of detecting a rotor angle in the present embodiment. FIG. 5 is an explanatory diagram showing a coordinate axis and a rotor angle of the rotating machine according to the present embodiment. FIG. 6 is an explanatory diagram showing a switching pattern in the second mode according to the present embodiment. The switching pattern in the second mode will be described with reference to FIGS. 4, 5 and 6.

As shown in FIG. 4, the motor M1 is provided with a magnet M that rotates with the rotation of the motor M1 and Hall elements Hu, Hv, and Hw for detecting the position of the magnet M. The magnet M is configured to rotate at the same angular velocity as the rotor of the motor M1. The angle of the magnet M may be the same as or different from the rotor angle θ of the motor M1. The magnet M and the Hall elements Hu, Hv, and Hw correspond to the rotation position sensor RS for detecting the rotor angle θ.

As shown in FIG. 5, the rotor angle θ is the angle of the north pole of the rotor R included in the motor M1. The reference (θ = 0) of the rotor angle θ is the direction of the U-phase armature reaction magnetic flux generated when a positive current is passed through the U-phase coil. The rotor angle θ is an electric angle.

Next, the driving of the switch elements S1 to S6 by the first control unit 21 will be described with reference to FIG. In the following description, the section where the rotor angle θ is from 150 degrees to 210 degrees is also referred to as section I. As shown in FIG. 6, the six sections of the rotor angle are also referred to as sections I to VI. In addition, FIG. 6 also shows the detected values of the Hall elements Hu, Hv, and Hw in each section.

The UH and UL shown in FIG. 6 correspond to a U-phase high-side switch (switch element S1) and a low-side switch (switch element S4), respectively. VH and VL correspond to a V-phase high-side switch (switch element S2) and a low-side switch (switch element S5), respectively. WH and WL correspond to a W-phase high-side switch (switch element S3) and a low-side switch (switch element S6), respectively.

For example, in section I, among the switch elements S1 to S6, the second control unit 22 switches each switch so that the switch element S1 corresponding to UH is turned ON (1) and the other switch elements are turned OFF (0). Drives elements S1 to S6.

For example, in section II, among the switch elements S1 to S6, the second control unit 22 switches each switch so that the switch element S6 corresponding to WL is turned ON (1) and the other switch elements are turned OFF (0). Drives elements S1 to S6.

Also in sections III to VI, the second control unit 22 drives the switch elements S1 to S6 in the switching pattern shown in FIG.

(2) Third Mode FIG. 7 is an explanatory diagram showing a switching pattern in the third mode according to the present embodiment. Both (a) and (b) of FIG. 7 show a switching pattern in the third mode.

In the switching pattern of FIG. 7A, among the switch elements S1 to S6, the switch elements S1, S2, and S3, which are switches corresponding to UP, VP, and WP (that is, high-side switches), are turned ON (1). The third control unit 23 drives the switch elements S1 to S6 so that the other is turned off (0).

In the switching pattern of FIG. 7B, among the switch elements S1 to S6, the switch elements S4, S5 and S6, which are switches corresponding to UN, VN and WN (that is, low-side switches), are turned ON (1), and the like. The third control unit 23 drives the switch elements S1 to S6 so as to turn OFF (0).

FIG. 8 is a timing diagram showing switching patterns in the first mode and the second mode in the present embodiment. In FIG. 8, each switch element S1 to S6 is driven in the first mode in the section before the time 0.3 seconds, and is driven in the second mode in the section after the time 0.3 seconds. FIG. 8 also shows the temporal change of the rotor angle θ.

In the section before the time 0.3 seconds in FIG. 8, each switch element S1 to S6 is driven by the first mode, that is, the three-phase PWM control using the rotor angle θ.

In the section after the time of 0.3 seconds in FIG. 8, each switch element S1 to S6 is driven in the second mode using the rotor angle θ. Specifically, the control of section III is started based on the rotor angle (about 270 degrees) at time 0.3 seconds, and then the controls of sections IV, V and VI are sequentially performed.

Next, two examples of the configuration of the control circuit 20 will be described. Specifically, (1) an example of a control circuit 20 for switching between the first control unit 21 and the second control unit 22, and (2) the first control unit 21, the second control unit 22, and the third control unit 23. An example of the control circuit 20 for switching the above will be described.

(1) An Example of a Control Circuit 20 for Switching Between the First Control Unit 21 and the Second Control Unit 22 FIG. 9 is a circuit diagram showing a first example of the control circuit 20 according to the present embodiment. FIG. 9 shows an example of a control circuit 20 that switches between the first control unit 21 and the second control unit 22.

FIG. 9 shows a first control unit 21, a second control unit 22, and a switching unit 24.

The first control unit 21 outputs a switching signal and signals UH, UL, VH, VL, WH and WL (also referred to as “signal UH or the like”).

The switching signal output by the first control unit 21 is a signal output by the first control unit 21 in order to switch to the control by the second mode based on the processing by the first control unit 21. The switching signal is, for example, a signal output when an abnormal operation of various microcomputers mounted on the electric vehicle 1 is detected.

The signal UH or the like output by the first control unit 21 is a PWM signal for driving the switch elements S1 to S6, and corresponds to a section before 0.3 seconds in FIG. The signal UH or the like output by the first control unit 21 is transmitted to the switching unit 24.

The second control unit 22 outputs a signal UH or the like based on the detected values by the Hall elements Hu, Hv and Hw. The second control unit 22 includes logic circuits, more specifically, NOR circuits 41, 43 and 45, and AND circuits 42, 44 and 46. The NOR circuit 41 outputs the NOR calculation result of the detected values of the Hall elements Hu and Hv as a signal UH. The AND circuit 42 outputs the AND calculation result of the detected values of the Hall elements Hu and Hv as a signal UL. For other logic circuits, as shown in FIG. 8, the logic operation results are output as signals VH, VL, WH and WL. The signal UH or the like output by the second control unit 22 is transmitted to the switching unit 24. The second control unit 22 shown in FIG. 9 is an example in the case of being configured by a logic circuit.

The switching unit 24 has an OR circuit 51 and a multiplexer 52.

The switching unit 24 acquires the signal UH or the like output by the first control unit 21 and the signal UH or the like output by the second control unit 22, and either the first control unit 21 or the second control unit 22 outputs the signal UH or the like. The signal UH or the like is selected by the multiplexer 52 and output. Further, the switching unit 24 can acquire the switching signal output by the first control unit 21 and the abnormality detection signal. The multiplexer 52 receives a signal output by the OR circuit 51 when receiving a switching signal or an abnormality detection signal, and selects and outputs a signal UH or the like output by the second control unit 22. For example, the multiplexer 52 switches each switch to the upper side on the paper surface when receiving the low potential from the OR circuit 51, and switches each switch to the lower side on the paper surface when receiving the high potential from the OR circuit 51. Make the above selection with.

When the second control unit 22 is realized by the microcomputer, the second control unit 22 receives the detected values from the Hall elements Hu, Hv and Hw, and takes the correspondence shown in FIG. 6 based on the received detected values. Use to perform the process of identifying the section. Then, the second control unit 22 executes a process of determining and outputting a signal UH or the like for turning each switch element S1 to S6 ON or OFF so as to have a switching pattern in the specified section.

FIG. 10 is a flow chart showing processing of a first example of the control circuit 20 in the present embodiment. It is assumed that the process shown in FIG. 10 is repeatedly executed at predetermined time intervals.

In step S101, when the first control unit 21 outputs a switching signal or an abnormality detection signal, the switching unit 24 acquires the output signal. The abnormality detection signal is a signal output when a predetermined abnormality is detected.

In step S102, the switching unit 24 determines whether or not an abnormality has been detected based on the signal acquired in step S101. For example, when the switching unit 24 acquires the switching signal or the abnormality detection signal in step S101, it determines that the abnormality has been detected. If it is determined that an abnormality has been detected (Yes in step S102), the process proceeds to step S104, and if not (No in step S102), the process proceeds to step S103.

In step S103, the switching unit 24 controls the multiplexer 52 so that the first control unit 21 controls the multiplexer 52. Specifically, the multiplexer 52 switches each switch on the upper side of the paper (see FIG. 9). The switching unit 24 maintains that state when it has already been controlled by the first control unit 21, and when it is controlled by the second control unit 22, it is controlled by the first control unit 21. Switch to.

In step S104, the switching unit 24 controls the multiplexer 52 so that the second control unit 22 controls it. Specifically, the multiplexer 52 switches each switch to the lower side on the paper (see FIG. 9). The switching unit 24 maintains that state when the control by the second control unit 22 has already been performed, and the control by the second control unit 22 when the control by the first control unit 21 has already been performed. Switch to.

When the steps S103 or S104 are completed, the series of processes shown in FIG. 10 is completed.

As a result, when the rotary machine control device 5 detects an abnormality in the state where the inverter 10 is driving the motor M1 (first mode) based on the first control by the first control unit 21, the second control unit 5 Based on the second control by 22, the inverter 10 can transition to the state in which the motor M1 is being driven (second mode). As a result, the rotary machine control device 5 can avoid the destruction of the elements of the inverter 10 while suppressing the occurrence of abrupt fluctuations in torque.

FIG. 11 is a circuit diagram showing a second example of the control circuit 20 according to the present embodiment. FIG. 11 is an example of a control circuit 20 that switches between the first control unit 21, the second control unit 22, and the third control unit 23. Of the configurations shown in FIG. 11, the same configurations as those shown in FIG. 9 are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 11 shows a first control unit 21, a second control unit 22, a third control unit 23, and a switching unit 24A. The switching unit 24A includes a switching unit 24 and a switching unit 24B.

The first control unit 21, the second control unit 22, and the switching unit 24 are the same as those shown in FIG.

The third control unit 23 is a circuit that outputs the low potential as signals UH, VH and WH, and outputs the high potential as signals UL, VL and WL. For example, the low potential is the ground potential, and the high potential is the power supply voltage of the control circuit 20 (5 V as an example).

The switching unit 24B includes an AND circuit 53 and a multiplexer 54.

The switching unit 24B acquires the signal UH or the like output by the switching unit 24 and the signal UH or the like output by the third control unit 23, and the signal UH or the like output by either the switching unit 24 or the third control unit 23. Is selected by the multiplexer 54 and output. Further, the switching unit 24B can acquire the output signal of the OR circuit 51 of the switching unit 24 and the predetermined voltage excess detection signal. The multiplexer 54 receives the signal output by the AND circuit 53 when the output signal and the predetermined voltage excess detection signal are received, and selects and outputs the signal UH or the like output by the third control unit 23. For example, the multiplexer 54 switches each switch to the upper side on the paper when receiving the low potential from the AND circuit 53, and switches each switch to the lower side on the paper when receiving the high potential from the AND circuit 53. Make the above selection with.

In this way, the switching unit 24A can switch between the control by the first control unit 21, the control by the second control unit 22, and the control by the third control unit 23 by the switching units 24 and 24B.

FIG. 12 is a flow chart showing processing of a second example of the control circuit 20 in the present embodiment.

In step S201, the switching units 24 and 24B acquire a signal. The signal that can be acquired by the switching unit 24 includes a switching signal output by the first control unit 21 and an abnormality detection signal. The signal that can be acquired by the switching unit 24B includes the output signal of the OR circuit 51 and the predetermined voltage excess detection signal.

In step S202, the switching unit 24 determines whether or not an abnormality has been detected based on the signal received in step S201. If it is determined that an abnormality has been detected (Yes in step S202), the process proceeds to step S211. If it is determined that no abnormality is detected (No in step S202), the process proceeds to step S203. When an abnormality is detected, the output signal of the OR circuit 51 becomes a high potential.

In step S203, the switching unit 24 controls the multiplexer 52 so that the first control unit 21 controls the multiplexer 52. Step S203 is the same as step S103 of FIG.

In step S211 the switching unit 24B determines whether or not the predetermined voltage excess detection signal has been received in step S201, that is, whether or not the voltage Vdc of the DC bus unit is less than the predetermined voltage Vlimit. If it is determined that the predetermined voltage excess detection signal has not been received (the voltage Vdc is less than the predetermined voltage Vlimit) (Yes in step S211), the process proceeds to step S212 and the predetermined voltage excess detection signal is received (voltage Vdc). Is equal to or higher than the predetermined voltage voltage) (No in step S211), the process proceeds to step S213.

In step S212, the switching unit 24B controls the multiplexers 52 and 54 so as to be controlled by the second control unit 22. Specifically, the multiplexer 52 switches each switch to the lower side on the paper surface, and the multiplexer 54 switches each switch to the upper side on the paper surface (see FIG. 11). The switching unit 24B maintains the state when the control by the second control unit 22 has already been performed, and when the control is already performed by the first control unit 21 or the third control unit 23, the switching unit 24B is the first. (Ii) Switch to control by the control unit 22.

In step S213, the switching unit 24B controls the multiplexers 52 and 54 so as to be controlled by the third control unit 23. Specifically, both the multiplexers 52 and 54 switch each switch to the lower side on the paper (see FIG. 11). If the control is already performed by the third control unit 23, the state is maintained, and if the control is already performed by the first control unit 21 or the second control unit 22, the third control unit 23 is used. Switch to control.

After completing steps S203, S212 or S213, the series of processes shown in FIG. 12 is completed.

As a result, the rotary machine control device 5 further transitions from the second mode to the third mode when the voltage of the DC bus portion rises after the transition from the first mode to the second mode by the process shown in FIG. be able to. Therefore, the rotary machine control device 5 can avoid the destruction of the elements of the inverter 10 while suppressing the occurrence of abrupt fluctuations in torque when transitioning from the first mode to the third mode via the second mode. ..

Hereinafter, changes in torque, voltage, and current of the motor M1 when the motor M1 is controlled by switching between the first mode, the second mode, and the third mode will be described.

FIG. 13 is an explanatory diagram showing an example of temporal changes in torque, voltage, and current of the motor M1 controlled by the rotary machine control device 5 in the present embodiment.

The upper, middle, and lower views of FIG. 13A show the torque, voltage, and current of the motor M1 when switching from the first control to the third control, respectively. The horizontal axis shows the time, and the vertical axis shows the torque, voltage, and current of the motor M1 in arbitrary units (AU), respectively. The same shall apply hereinafter. The configuration for switching from the first control to the third control in FIG. 13A corresponds to the conventional configuration of Patent Document 1.

The switching from the first control to the third control is performed at the time t1.

As shown in the upper part of FIG. 13A, the torque takes a substantially constant value a (however a> 0) in the first control, and the torque takes a substantially constant value b (however b <0) in the third control. Take. Further, the torque converges to the value b while vibrating after an overshoot occurs after switching from the first control to the third control.

As shown in the middle stage of FIG. 13A, the voltage Vdc becomes substantially constant before and after the switching from the first control to the third control. The voltage Vdc does not rise at least by the third control (three-phase short-circuit control).

As shown in the lower part of FIG. 13 (a), the currents iq and id show the behavior of oscillating and converging to a constant value after the overshoot before and after the switching from the first control to the third control. .. Based on the behavior of the currents iq and id, as shown in the upper part of FIG. 13 (a), the torque converges to a constant value while oscillating.

The upper, middle, and lower views of FIG. 13B show the torque, voltage, and current of the motor M1 when switching from the first control to the second control, respectively.

The switching from the first control to the second control is performed at the time t1.

As shown in the upper part of FIG. 13B, the torque takes a substantially constant value a in the first control, and the torque oscillates in a relatively small width around the value b in the second control. The width of the overshoot after switching from the first control to the second control is significantly reduced as compared with the width of the overshoot shown in FIG. 13 (a). As shown in the middle stage of FIG. 13 (b), the voltage Vdc shows a slight increase in the second control.

As shown in the lower part of FIG. 13B, the currents iq and id exhibit behavior similar to torque before and after switching from the first control to the second control.

The upper, middle, and lower views of FIG. 13C show the torque, voltage, and current of the motor M1 when switching from the first control to the second control and then from the second control to the third control, respectively. Is shown.

The switching from the first control to the second control is performed at the time t1. The switching from the second control to the third control is performed at the time when the voltage Vdc exceeds the predetermined voltage Vlimit (time t2).

The behaviors of the torque, voltage, and current from the time t0 to the time when the voltage Vdc exceeds the predetermined voltage Vlimit (time t2) are the same as those shown in FIG. 13 (b), respectively.

As shown in the upper part of (c) of FIG. 13, the torque takes a substantially constant value b in the third control. After switching from the second control to the third control, the torque converges to the value b while oscillating with little overshoot. The amplitude of the vibration after convergence is the same as in the case of FIG. 13 (a).

As shown in the middle stage of (c) of FIG. 13, in the third control, the voltage Vdc takes a substantially constant value at a predetermined voltage Vlimit.

As shown in the lower part of (c) of FIG. 13, in the third control, the currents iq and id converge to a constant value while oscillating with behavior similar to torque, that is, with almost no overshoot. Show behavior. The amplitude of the vibration after convergence is the same as in the case of FIG. 13 (a).

In this way, when switching from the first control to the second control, overshoot and vibration of torque and current can be suppressed as compared with the conventional case of switching from the first control to the third control. Further, by switching from the first control to the second control and then switching from the second control to the third control, an increase in the voltage Vdc can be suppressed.

Further, when switching from the first control to the third control via the second control, it is possible to suppress torque and current overshoot and vibration as compared with the conventional case of switching directly from the first control to the third control. it can.

As described above, the rotary machine control device of the present embodiment can suppress abrupt fluctuations in torque by switching from the first control unit to the second control unit. The second control unit drives the inverter so that at least a part of the power generated by the three-phase rotating machine becomes reactive power, thereby generating braking force while suppressing an increase in the voltage of the DC bus part of the inverter. Let me. Further, the occurrence of abrupt fluctuations in torque is suppressed when switching from the first control unit to the second control unit. As a result, the rotary machine control device can avoid the destruction of the inverter element while suppressing the occurrence of abrupt fluctuations in torque.

Further, since at least one of the second control unit and the switching unit of the rotary machine control device is composed of a logic circuit, the rotor control device has higher resistance to failure than the case where it is composed of an arithmetic unit or a processor. Therefore, the rotary machine control device can improve the resistance to failure and avoid the destruction of the inverter element while suppressing the occurrence of abrupt fluctuations in torque.

Further, in principle, the rotary machine control device controls the three-phase rotary machine by the first control unit, and when the circuit breaker is disconnected or the overvoltage of the DC bus portion is actually detected, the rotary machine control device is sent to the second control unit. Can be switched. As a result, the rotary machine control device can appropriately control the three-phase rotary machine by performing control by the first control unit at normal times and controlling by the second control unit as needed. As a result, the rotary machine control device performs control by the second control unit when control by the second control unit is required, thereby avoiding destruction of the inverter element while suppressing the occurrence of sudden fluctuations in torque. can do.

Further, the rotary machine control device can suppress the overvoltage from being applied to the inverter by controlling the three-phase rotary machine by the third control, that is, the three-phase short-circuit control. Further, the above-mentioned three-phase short-circuit control is performed when the overvoltage of the DC bus portion of the inverter is actually detected. As a result, even when the rotary machine control device is being controlled by the first control unit or the second control unit, the inverter is overvoltageed by being controlled by the third control unit as necessary. Can be suppressed. As a result, the rotary machine control device can avoid the destruction of the inverter element while suppressing the occurrence of abrupt fluctuations in torque by further using the three-phase short-circuit control.

Further, since the third control unit of the rotary machine control device is composed of a logic circuit, the resistance to failure is higher than that of the case where the rotary machine control device is composed of an arithmetic unit or a processor. Therefore, the rotary machine control device can improve the resistance to failure and avoid the destruction of the inverter element while suppressing the occurrence of abrupt fluctuations in torque.

(Embodiment 2)
In the present embodiment, a technique capable of suppressing the generation of load torque will be described for a rotary machine control device capable of avoiding destruction of inverter elements while suppressing the occurrence of sudden fluctuations in torque.

Regarding the configuration of the rotary machine control device 5 in the present embodiment, mainly the parts different from the rotary machine control device 5 in the first embodiment will be described, and the same parts as the rotary machine control device 5 in the first embodiment will have the same reference numerals. Is added and the description is omitted.

The configuration of the rotary machine control device 5 according to the second embodiment is shown as the same circuit diagram as the configuration of the rotary machine control device 5 according to the first embodiment (see FIG. 2).

In the rotary machine control device 5 according to the second embodiment, the function of the control circuit 20 is different from that of the control circuit 20 in the first embodiment. More specifically, in the rotary machine control device 5 according to the second embodiment, the function of the switching unit 24 is different from that of the switching unit 24 in the first embodiment.

The switching unit 24 switches the control of driving the inverter 10. Specifically, the switching unit 24 switches between the first control unit 21, the second control unit 22, and the third control unit 23 as a control unit that controls the drive of the inverter 10. For example, the switching unit 24 calculates the rotation speed of the motor M1 based on the output from the rotation position sensor RS when the third control unit 23 is driving the inverter 10, and the calculated rotation speed is the predetermined rotation speed. If the following occurs, the third control unit 23 is switched to the second control unit 22.

Further, the switching unit 24 switches from the first control unit 21 to the third control unit 22 as a control unit that controls the drive of the inverter 10 when, for example, a predetermined abnormality is detected. The predetermined abnormality is, for example, that the circuit breaker 32 electrically connected to the DC bus portion of the inverter 10 has become non-conducting, and the overvoltage detection signal is output from the overvoltage detection circuit electrically connected to the DC bus portion. This includes the fact that the signal has been output, or that a signal indicating that an abnormal operation of various microcomputers mounted on the electric vehicle 1 has been detected has been output. The switching unit 24 receives a signal output when it is detected that the circuit breaker 32 electrically connected to the DC bus of the inverter 10 has become non-conducting, so that the circuit breaker 32 can be operated. It is possible to know that it has become non-conducting.

The switching unit 24 may be realized by a logic circuit or may be realized by a microcomputer.

FIG. 14 is a timing diagram showing switching patterns in the second mode and the third mode in the present embodiment. In FIG. 14, each switch element S1 to S6 is driven in the third mode in the section before the time 0.3 seconds, and is driven in the second mode in the section after the time 0.3 seconds. In addition, FIG. 14 also shows the temporal change of the rotor angle θ.

In the section before the time 0.3 seconds in FIG. 14, each switch element S1 to S6 is driven by the third mode, that is, the three-phase short-circuit control using the rotor angle θ.

In the section after the time of 0.3 seconds in FIG. 14, each switch element S1 to S6 is driven in the second mode using the rotor angle θ. Specifically, the control of section III is started based on the rotor angle (about 270 degrees) at time 0.3 seconds, and then the controls of sections IV, V and VI are sequentially performed.

Next, an example of the configuration of the control circuit 20 will be described.

FIG. 15 is a circuit diagram showing an example of the control circuit 20 according to the present embodiment. The circuit diagram of FIG. 15 is a circuit diagram showing a concept of control in a range in which the voltage Vdc does not exceed a predetermined voltage Vlimit.

FIG. 15 shows a first control unit 21, a second control unit 22, a third control unit 23, and a switching unit 24A.

The first control unit 21 outputs a switching signal and signals UH, UL, VH, VL, WH and WL (also referred to as “signal UH or the like”).

The switching signal output by the first control unit 21 is a signal output by the first control unit 21 in order to switch to the control by the second mode based on the processing by the first control unit 21. The switching signal is, for example, a signal output when an abnormal operation of various microcomputers mounted on the electric vehicle 1 is detected.

The signal UH or the like output by the first control unit 21 is a PWM signal for driving the switch elements S1 to S6. The signal UH or the like output by the first control unit 21 is transmitted to the switching unit 24.

The second control unit 22 outputs a signal UH or the like based on the detected values by the Hall elements Hu, Hv and Hw. The second control unit 22 includes logic circuits, more specifically, NOR circuits 41, 43 and 45, and AND circuits 42, 44 and 46. The NOR circuit 41 outputs the NOR calculation result of the detected values of the Hall elements Hu and Hv as a signal UH. The AND circuit 42 outputs the AND calculation result of the detected values of the Hall elements Hu and Hv as a signal UL. For other logic circuits, as shown in FIG. 8, the logic operation results are output as signals VH, VL, WH and WL. The signal UH or the like output by the second control unit 22 is transmitted to the switching unit 24. The second control unit 22 shown in FIG. 9 is an example in the case of being configured by a logic circuit.

The third control unit 23 is a circuit that outputs the low potential as signals UH, VH and WH, and outputs the high potential as signals UL, VL and WL. For example, the low potential is the ground potential, and the high potential is the power supply voltage of the control circuit 20 (5 V as an example).

The switching unit 24A has a switching unit 24 and a switching unit 24B.

The switching unit 24 has an OR circuit 51 and a multiplexer 52.

The switching unit 24 acquires the signal UH or the like output by the first control unit 21 and the signal UH or the like output by the second control unit 22, and either the first control unit 21 or the second control unit 22 outputs the signal UH or the like. The signal UH or the like is selected by the multiplexer 52 and output. Further, the switching unit 24 can acquire the switching signal output by the first control unit 21 and the abnormality detection signal. The multiplexer 52 receives a signal output by the OR circuit 51 when receiving a switching signal or an abnormality detection signal, and selects and outputs a signal UH or the like output by the second control unit 22. For example, the multiplexer 52 switches each switch to the upper side on the paper surface when receiving the low potential from the OR circuit 51, and switches each switch to the lower side on the paper surface when receiving the high potential from the OR circuit 51. Make the above selection with.

The switching unit 24B includes an AND circuit 53, a multiplexer 54, and a rotation speed calculation unit 55.

The switching unit 24B acquires the signal UH or the like output by the switching unit 24 and the signal UH or the like output by the third control unit 23, and the signal UH or the like output by either the switching unit 24 or the third control unit 23. Is selected by the multiplexer 54 and output. Further, the switching unit 24B acquires the output signal of the OR circuit 51 of the switching unit 24 and the high-speed rotation detection signal. The high-speed rotation speed detection signal can be generated, for example, by the rotation speed calculation unit 55.

The rotation speed calculation unit 55 calculates the speed of the motor M1 as the rotation speed. Specifically, the rotation speed calculation unit 55 calculates the rotation speed of the motor M1 using the detected values of the Hall elements Hu, Hv, and Hw, and determines whether or not the calculated rotation speed is equal to or higher than the predetermined rotation speed. judge. Then, when it is determined that the calculated rotation speed is equal to or higher than the predetermined rotation speed, a high-speed rotation detection signal is output. Here, the high-speed rotation detection signal has a high potential when the rotation speed is equal to or higher than the predetermined rotation speed, and a low potential when the rotation speed is less than the predetermined rotation speed. The detection values of the Hall elements Hu, Hv and Hw used for calculating the rotation speed by the rotation speed calculation unit 55 can also be the detection values of the Hall elements Hu, Hv and Hw input to the second control unit 22. The predetermined rotation speed is a rotation speed before the rotation speed of the motor M1 decreases to generate a steep load torque during control by the third control unit 23.

The multiplexer 54 receives the signal output by the AND circuit 53 when receiving the output signal of the OR circuit 51 of the switching unit 24 and the high-speed rotation detection signal, and selects the signal UH or the like output by the third control unit 23. And output. For example, the multiplexer 54 switches each switch to the upper side on the paper when receiving the low potential from the AND circuit 53, and switches each switch to the lower side on the paper when receiving the high potential from the AND circuit 53. Make the above selection with.

In this way, the switching unit 24A can switch between the control by the first control unit 21, the control by the second control unit 22, and the control by the third control unit 23 by the switching units 24 and 24B.

When the second control unit 22 is realized by the microcomputer, the second control unit 22 receives the detected values from the Hall elements Hu, Hv and Hw, and takes the correspondence shown in FIG. 6 based on the received detected values. Use to perform the process of identifying the section. Then, the second control unit 22 executes a process of determining and outputting a signal UH or the like for turning each switch element S1 to S6 ON or OFF so as to have a switching pattern in the specified section.

FIG. 16 is a flow chart showing the processing of the control circuit 20 in the present embodiment. It is assumed that the process shown in FIG. 16 is repeatedly executed at predetermined time intervals.

In step S301, when the first control unit 21 outputs a switching signal or an abnormality detection signal, the switching unit 24 acquires the output signal. The abnormality detection signal is a signal output when a predetermined abnormality is detected. Further, the switching unit 24B (rotation speed calculation unit 55) acquires the rotation speed of the motor M1.

In step S302, the switching units 24 and 24B detect an abnormality based on the signal and the rotation speed acquired in step S301, and determine whether or not the acquired rotation speed is equal to or less than the predetermined rotation speed. For example, when the switching unit 24 acquires the switching signal or the abnormality detection signal in step S301, it determines that the abnormality has been detected. If an abnormality is detected and it is determined that the rotation speed is less than or equal to the predetermined rotation speed (Yes in step S302), the process proceeds to step S303, and if not (No in step S302), the process proceeds to step S303. The process proceeds to step S304.

In step S303, the switching unit 24 controls the multiplexers 52 and 54 so that the second control unit 22 controls them. Specifically, the multiplexer 52 switches each switch to the lower side on the paper surface, and the multiplexer 54 switches each switch to the upper side on the paper surface (see FIG. 15). The switching unit 24 maintains that state when it has already been controlled by the second control unit 22, and when it is controlled by the first control unit 21 or the third control unit 23, the switching unit 24 has a second position. (Ii) Switch to control by the control unit 22.

In step S304, the switching unit 24 controls the multiplexers 52 and 54 so as to be controlled by the third control unit 23. Specifically, both the multiplexers 52 and 54 toggle each switch down on the paper (see FIG. 15). The switching unit 24 maintains that state when the control is already performed by the third control unit 23, and when the control is performed by the first control unit 21 or the second control unit 22, the switching unit 24 is the first. (3) Switch to control by the control unit 23.

When step S303 or S304 is completed, the series of processes shown in FIG. 16 is completed.

As a result, the rotary machine control device 5 determines that the rotation speed is equal to or less than the predetermined rotation speed in the state where the inverter 10 is driving the motor M1 (third mode) based on the third control by the third control unit 23. When detected, the inverter 10 can transition to the state of driving the motor M1 (second mode) based on the second control by the second control unit 22. As a result, the rotary machine control device 5 can avoid the destruction of the element of the inverter 10 while suppressing the generation of the load torque.

(Modification example 1)
Hereinafter, modifications of each of the above embodiments will be described.

Specifically, in this modification, the first control mode, the second control mode, and the third control mode are transitioned in this order (see the first embodiment), and then the third mode is transitioned to the second mode. (See Embodiment 2) An example will be described.

In the present embodiment, as the control circuit 20 of the rotary machine control device 5, the concept of the control circuit 20 of the second embodiment can be used when transitioning from the third mode to the second mode (see FIG. 15).

First, the control circuit 20 controls by transitioning between the first mode, the second mode, and the third mode in this order, as in the first embodiment.

Then, after the above transition, in the third mode, when it is determined that the rotation speed of the motor M1 acquired from the rotation speed calculation unit 55 is equal to or less than the predetermined rotation speed, the second mode is set. Transition. The timing of transitioning to the second mode is determined based on the timing peculiar to the motor M1.

FIG. 17 is an explanatory diagram showing a first example of temporal changes in torque, voltage, and current of a motor controlled by the rotary machine control device 5 in this modified example.

The upper, middle, and lower views of FIG. 17 show the torque, voltage, and current of the motor M1 when transitioning between the first mode 61, the second mode 62, the third mode 63, and the second mode 64 in this order, respectively. Is shown. The display on the horizontal axis and the vertical axis is the same as in FIG. 13A and the like.

The transitions of the first mode 61, the second mode 62, and the third mode 63 are the same as the transitions in the first embodiment. Here, it is known that if the third mode 63 is maintained for a while, the rotation speed of the motor M1 decreases, and a negative torque 66 is generated at the timing when the rotation speed of the motor M1 reaches a certain rotation speed. The negative torque 66 is a load torque (brake torque) that lowers the rotation speed of the motor, and can be a factor for sudden deceleration of the vehicle.

The above "certain rotation speed" is a rotation speed peculiar to the motor, and if a change in the rotation speed of the motor is observed, the timing at which the rotation speed of the motor reaches the above "certain rotation speed" is determined in advance. You can know.

Therefore, as shown in this modification, the rotary machine control device 5 transitions from the third mode 63 to the second mode 64 at the timing t3 before the timing when the negative torque 66 is generated. The timing of transitioning to the second mode 64 can be estimated from the rotation speed of the motor M1. That is, the rotary machine control device 5 continuously acquires the rotation speed of the motor M1, and the timing at which the acquired rotation speed of the motor M1 is estimated to reach a rotation speed slightly higher than the rotation speed at which the torque 66 is generated is determined. , Determined as timing t3. The rotation speed slightly larger than the rotation speed at which the torque 66 is generated may be, for example, the rotation speed obtained by adding a constant to the rotation speed at which the torque 66 is generated, or a constant multiple of the rotation speed at which the torque 66 is generated (for example, 1.1). (Double, etc.) may be used.

By doing so, the rotation speed of the motor M1 can be reduced while avoiding the generation of the negative torque 66, and the motor M1 can be directed to stop.

(Modification 2)
In this modification, an example of transitioning from the second mode to the third mode after the transition of the modification 1 will be described.

In the second mode 64 after the transition from the third mode 63 as in the first modification, the voltage Vdc gradually increases. When the voltage Vdc increases, it is desirable that the voltage Vdc is controlled so as not to exceed a predetermined voltage Vlimit.

Therefore, in the present modification, the rotary machine control device 5 transitions from the second mode 64 to the third mode 65 at the timing t4 where the voltage Vdc does not exceed the predetermined voltage Vlimit.

FIG. 18 is a flow chart showing the processing of the control circuit 20 in this modification. It is assumed that the process shown in FIG. 18 is repeatedly executed at predetermined time intervals after the time t2 in FIG. Therefore, the abnormality has already been detected.

Before executing step S401, the switching unit 24B (rotation speed calculation unit 55) acquires the rotation speed of the motor M1 (see FIG. 15) and the predetermined voltage excess detection signal (see FIG. 11).

In step S401, the switching unit 24B determines whether or not a predetermined voltage excess detection signal has been received, that is, whether or not the voltage Vdc of the DC bus unit is less than the predetermined voltage Vlimit. If it is determined that the predetermined voltage excess detection signal has not been received (the voltage Vdc is less than the predetermined voltage Vlimit) (Yes in step S401), the process proceeds to step S402 and the predetermined voltage excess detection signal is received (voltage Vdc). Is equal to or higher than the predetermined voltage voltage) (No in step S401), the process proceeds to step S404.

In step S402, the switching unit 24B determines whether or not the acquired rotation speed is equal to or less than the predetermined rotation speed based on the signal and the rotation speed acquired in advance. If it is determined that it is detected that the rotation speed is equal to or less than the predetermined rotation speed (Yes in step S402), the process proceeds to step S404, and if not (No in step S402), the process proceeds to step S403.

In step S403, the switching unit 24B controls the multiplexers 52 and 54 so as to be controlled by the second control unit 22. Specifically, the multiplexer 52 switches each switch to the lower side on the paper surface, and the multiplexer 54 switches each switch to the upper side on the paper surface (see FIG. 15). The switching unit 24B maintains that state when it has already been controlled by the second control unit 22, and when it is controlled by the third control unit 23, it is controlled by the second control unit 22. Switch to.

In step S404, the switching unit 24B controls the multiplexer 54 so that the third control unit 22 controls it. Specifically, the multiplexer 54 switches each switch to the lower side on the paper (see FIG. 15). The switching unit 24B maintains that state when it has already been controlled by the third control unit 23, and when it is controlled by the second control unit 22, it is controlled by the third control unit 23. Switch to.

When step S403 or S404 is completed, the series of processes shown in FIG. 18 is completed.

FIG. 19 is an explanatory diagram showing a second example of temporal changes in torque, voltage, and current of a motor controlled by a rotary machine control device in Modification 2 of each embodiment.

As described above, in the second mode 64, the voltage Vdc gradually increases.

The rotary machine control device 5 transitions from the second mode 64 to the third mode 65 at the time t4, which is the timing when the voltage Vdc reaches the predetermined voltage Vlimit. In the third mode 65, the voltage Vdc is maintained at a constant value, in other words, is controlled so as not to exceed a predetermined voltage Vlimit.

As a result, in the rotary machine control device 5, the voltage Vdc reaches the predetermined voltage Vlimit in the state where the inverter 10 is driving the motor M1 (second mode) based on the second control by the second control unit 22. When detected, the inverter 10 can transition to the state of driving the motor M1 (third mode) based on the third control by the third control unit 23. As a result, the rotary machine control device 5 can reduce the rotation speed of the motor M1 so that the voltage Vdc does not exceed the predetermined voltage Vlimit, and cause the motor M1 to stop.

The operation of FIG. 19 can be summarized as follows.

First, from time t0 to time t1, no abnormality has occurred, and the motor M1 is normally driven by the first mode 61.

Next, when the circuit breaker 32 is disconnected or the overvoltage of the DC bus is detected at time t1, the switching unit 24 switches from the first control unit 21 to the second control unit 22 and switches by the second mode 62. While suppressing the torque fluctuation of the motor M1 of the above, the voltage Vdc is controlled so as not to become an overvoltage (exceeding a predetermined voltage Vlimit), and the destruction of the element of the inverter 10 is avoided.

Next, at time t2, when a period (a period from time t1 to time t2) in which torque fluctuation of the motor M1 does not occur even when switching to the third control unit 23 elapses, the switching unit 24B starts from the second control unit 22. Switch to the third control unit 23. As a result, the voltage Vdc that has gradually increased can be stabilized by the third mode 63.

Next, at time t3, when the rotation speed of the motor M1 becomes less than the predetermined rotation speed before generating the load torque at low speed (at low rotation speed), the switching unit 24B moves from the third control unit 23 to the second. Switch to the control unit 22. As a result, the generation of unnecessary load torque of the motor M1 is suppressed by the second mode 64 again.

Next, at time t4, when the voltage Vdc reaches the predetermined voltage Vlimit, the switching unit 24B switches from the second control unit 22 to the third control unit 23. As a result, the third mode 65 can be controlled so that the voltage Vdc does not exceed the predetermined voltage Vlimit.

As described above, the second mode 62, 64 and the third mode 63, 65 are set so that the switching units 24 and 24B alternately repeat the second control unit 22 and the third control unit 23 after the time t1. By transitioning and switching, it is possible to suppress the generation of unnecessary load torque of the motor M1 and to prevent the voltage Vdc from reaching an overvoltage.

As described above, the rotary machine control device of the present embodiment and the modified example can switch between the third control unit and the second control unit. Therefore, when the third control unit drives the inverter, the rotary machine is used. By switching to the second control unit in the low speed range of, it is possible to suppress the generation of load torque at low speed of the rotating machine. Further, since the second control unit drives the inverter so that at least a part of the electric power generated by the three-phase rotating machine becomes reactive power, it is possible to suppress an increase in the voltage of the DC bus portion of the inverter. As a result, the rotary machine control device can avoid the destruction of the inverter element while suppressing the generation of the load torque.

Further, since the rotary machine control device switches from the second control unit to the third control unit when the voltage Vdc of the DC bus unit reaches the predetermined voltage voltage, the voltage Vdc is the predetermined voltage in the third control, that is, the three-phase short circuit control. Control so that the voltage is not exceeded. Therefore, it is possible to avoid the destruction of the inverter element.

Further, in principle, the rotary machine control device controls the three-phase rotary machine by the first control unit, and when the circuit breaker is disconnected or the overvoltage of the DC bus portion is actually detected, the rotary machine control device is sent to the third control unit. Can be switched. As a result, the rotary machine control device can appropriately control the three-phase rotary machine by performing control by the first control unit at normal times and controlling by the third control unit as needed. As a result, the rotary machine control device can avoid the destruction of the inverter element by performing the control by the third control unit when the control by the third control unit is required.

Further, since at least one of the second control unit, the third control unit, and the switching unit of the rotary machine control device is composed of a logic circuit, it is more resistant to failure than the case where it is composed of an arithmetic unit or a processor. high. Therefore, the rotary machine control device can improve the resistance to failure and avoid the destruction of the inverter element while suppressing the generation of the load torque generated at the low speed of the rotary machine.

In the present embodiment, the speed of the rotating machine (motor M1) is calculated by the rotation speed calculation unit 55 as the rotation speed, but the present invention is not limited to this configuration, and for example, from the upper ECU of the electric vehicle 1. The control circuit 20 may take in the vehicle speed information and obtain the speed of the rotating machine based on the vehicle speed information.

Although the rotary machine control device and the like according to one or more aspects have been described above based on the embodiment, the present invention is not limited to this embodiment. As long as the gist of the present invention is not deviated, various modifications that can be conceived by those skilled in the art are applied to the present embodiment, and a form constructed by combining components in different embodiments is also within the scope of one or more embodiments. May be included within.

The present invention can be used in a vehicle drive device for driving an electric vehicle.

1 Electric vehicle 2 Drive wheels 3 Power transmission mechanism 5 Rotating machine control device 10 Inverter 20 Control circuit 21 1st control unit 22 2nd control unit 23 3rd control unit 24, 24A, 24B Switching unit 30 Drive circuit 32 Circuit breaker 40 3 Phase bridge circuit 41, 43, 45 NOR circuit 42, 44, 46, 53 AND circuit 52, 54 multiplexer 61 1st mode 62, 64 2nd mode 63, 65 3rd mode C1 smoothing capacitor CSu, CSv, CSw Current sensor Hu , Hv, Hw Hall element Lg Grounding wire Lp Power supply line M Magnet M1 Motor P1 Battery R Rotor RS Rotational position sensor S1, S2, S3, S4, S5, S6 Switch element

Claims (12)

An inverter that drives a three-phase rotator and has a U-phase switching circuit, a V-phase switching circuit, and a W-phase switching circuit.
A rotor position detector that detects the rotor position of the three-phase rotary machine, and
The rotor position detector and a control circuit electrically connected to the inverter are provided.
The control circuit
A first control unit that applies a voltage to the three-phase rotor using the inverter so that the current or torque of the three-phase rotor follows the command current or command torque.
A second control unit that applies a voltage to the three-phase rotary machine using the inverter,
It has a switching unit for switching between the first control unit and the second control unit.
The second control unit
(A) The period in which the rotor angle obtained from the rotor position detected by the rotor position detector is ± 30 ° about the zero cross point of the induced voltage in the U phase of the three-phase rotating machine is the U-phase th. Two periods are defined, and the period between the second period of the adjacent U phase is defined as the first period of the U phase.
(B) The period in which the rotor angle is ± 30 ° around the zero cross point of the induced voltage in the V phase of the three-phase rotating machine is defined as the second period of the V phase, and the second period of the adjacent V phase. The period between the two is defined as the first period of the V phase,
(C) The period in which the rotor angle is ± 30 ° around the zero cross point of the induced voltage in the W phase of the three-phase rotating machine is defined as the second period of the W phase, and the second period of the adjacent W phase. When the period between the two is defined as the first period of the W phase,
A voltage is applied to the three-phase rotary machine by driving the inverter based on the rotor angle.
In driving the inverter,
(I) The high-side switch and the low-side switch of the U-phase switching circuit are in a non-conducting state during the entire period of the first period of the U-phase, and the high-side switch of the V-phase switching circuit is high during the entire period of the first period of the V-phase. The inverter is driven so that the side switch and the low side switch are in the non-conducting state, and the high side switch and the low side switch of the W phase switching circuit are in the non-conducting state during the entire first period of the W phase.
(Ii) Either the high-side switch or the low-side switch of the U-phase switching circuit becomes conductive during a part or the whole period of the second period of the U-phase, and a part of the second period of the V-phase. Either the high-side switch or the low-side switch of the V-phase switching circuit becomes conductive during a period or the entire period, and the high of the W-phase switching circuit during a part or the whole period of the second period of the W phase. A rotary machine control device that drives the inverter so that either the side switch or the low side switch is in a conductive state. The rotary machine control device according to claim 1, wherein at least one of the second control unit and the switching unit is composed of a logic circuit. In the switching unit, the circuit breaker electrically connected to the DC bus portion of the inverter becomes non-conducting, or an overvoltage detection signal is output from the overvoltage detection circuit electrically connected to the DC bus portion. The rotary machine control device according to claim 1 or 2, wherein the first control unit is switched to the second control unit in the case of The control circuit
The inverter is controlled so that one of the high-side switch and the low-side switch in the U-phase switching circuit, the V-phase switching circuit, and the W-phase switching circuit is in a conductive state and the other is in a non-conducting state. Further equipped with a third control unit
In addition to the first control unit and the second control unit, the switching unit also switches the third control unit.
The rotary machine control device according to claim 3, wherein the switching unit switches from the second control unit to the third control unit when the voltage in the DC bus unit is equal to or higher than a predetermined voltage. The switching unit is
When the third control unit is driving the inverter, the rotation speed of the three-phase rotary machine is calculated based on the output from the rotor position detector.
The rotary machine control device according to claim 4, wherein when the calculated rotation speed becomes equal to or less than a predetermined rotation speed, the third control unit is switched to the second control unit. The control circuit
The inverter is controlled so that one of the high-side switch and the low-side switch in the U-phase switching circuit, the V-phase switching circuit, and the W-phase switching circuit is in a conductive state and the other is in a non-conducting state. Further equipped with a third control unit
In addition to the first control unit and the second control unit, the switching unit also switches the third control unit.
In the switching unit, the circuit breaker electrically connected to the DC bus portion of the inverter becomes non-conducting, or an overvoltage detection signal is output from the overvoltage detection circuit electrically connected to the DC bus portion. The rotary machine control device according to claim 1, wherein the first control unit is switched to the third control unit. The switching unit is
When the third control unit is driving the inverter, the rotation speed of the three-phase rotary machine is calculated based on the output from the rotor position detector.
The rotary machine control device according to claim 6, wherein when the calculated rotation speed becomes equal to or less than a predetermined rotation speed, the third control unit is switched to the second control unit. The rotary machine control device according to claim 4 or 6, wherein the third control unit is composed of a logic circuit. A claim that the switching unit switches from the second control unit to the third control unit when the rotation speed is equal to or less than the predetermined rotation speed and the voltage in the DC bus unit is equal to or higher than the predetermined voltage. 5. The rotary machine control device according to 5. 7. The switching unit switches from the second control unit to the third control unit when the rotation speed is equal to or lower than the predetermined rotation speed and the voltage in the DC bus portion is equal to or higher than the predetermined voltage. The rotary machine control device described in 1. It is a control method of the rotary machine control device.
The rotary machine control device is
An inverter that drives a three-phase rotator and has a U-phase switching circuit, a V-phase switching circuit, and a W-phase switching circuit.
A rotor position detector that detects the rotor position of the three-phase rotary machine, and
The rotor position detector and a control circuit electrically connected to the inverter are provided.
The control method is
A first control step of applying a voltage to the three-phase rotor using the inverter so that the current or torque of the three-phase rotor follows the command current or command torque.
A second control step of applying a voltage to the three-phase rotary machine using the inverter, and
It has a switching step for switching between the first control step and the second control step.
The second control step is
(A) The period in which the rotor angle obtained from the rotor position detected by the rotor position detector is ± 30 ° about the zero cross point of the induced voltage in the U phase of the three-phase rotating machine is the U-phase th. Two periods are defined, and the period between the second period of the adjacent U phase is defined as the first period of the U phase.
(B) The period in which the rotor angle is ± 30 ° around the zero cross point of the induced voltage in the V phase of the three-phase rotating machine is defined as the second period of the V phase, and the second period of the adjacent V phase. The period between the two is defined as the first period of the V phase,
(C) The period in which the rotor angle is ± 30 ° around the zero cross point of the induced voltage in the W phase of the three-phase rotating machine is defined as the second period of the W phase, and the second period of the adjacent W phase. When the period between the two is defined as the first period of the W phase,
A voltage is applied to the three-phase rotary machine by driving the inverter based on the rotor angle.
In driving the inverter,
(I) The high-side switch and the low-side switch of the U-phase switching circuit are in a non-conducting state during the entire period of the first period of the U-phase, and the high-side switch of the V-phase switching circuit is high during the entire period of the first period of the V-phase. The inverter is driven so that the side switch and the low side switch are in the non-conducting state, and the high side switch and the low side switch of the W phase switching circuit are in the non-conducting state during the entire first period of the W phase.
(Ii) Either the high-side switch or the low-side switch of the U-phase switching circuit becomes conductive during a part or the whole period of the second period of the U-phase, and a part of the second period of the V-phase. Either the high-side switch or the low-side switch of the V-phase switching circuit becomes conductive during a period or the entire period, and the high of the W-phase switching circuit during a part or the whole period of the second period of the W phase. A control method for driving the inverter so that either the side switch or the low side switch is in a conductive state. The control method is
It further has a third control step of applying a voltage to the three-phase rotary machine using the inverter.
The third control step is
The inverter is driven so that one of the high-side switch and the low-side switch in the U-phase switching circuit, the V-phase switching circuit, and the W-phase switching circuit is in a conductive state and the other is in a non-conducting state. The control method according to claim 11.

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