JP5403338B2 - Synchronous machine - Google Patents

Description

  The present invention relates to a synchronous machine having a stator, a rotor, a rectifying element, a drive unit, a control unit, and the like.

  As a conventional synchronous machine, an example of a technique in which a rectifying element is connected in series to a rotor coil (field winding) and the rotor is excited by an armature current energized to the stator coil (armature winding) is disclosed. (For example, refer to Patent Document 1). In this technique, a pulse voltage is applied to the fundamental wave of the armature current for a predetermined period shorter than one period of the armature current (meaning that it is superimposed, the same applies hereinafter) and energized. By energizing the rotor coil with a field current, the rotor is excited.

JP 2007-185082 A

  Here, there is a case where control is performed in a mode (for example, a rectangular wave mode or an overmodulation mode) in which the modulation rate is a certain value or more. The constant value corresponds to “1.15” in a specific control (for example, an overmodulation mode in the case of using a third-order harmonic superposition method or a two-phase modulation method in pulse width modulation (PWM) control). 1 ”corresponds. When control is performed in this mode, when a pulse voltage is applied to the fundamental wave of the armature current according to the technique of Patent Document 1, the output voltage is large, so that the phase voltage is unbalanced. For example, as shown in FIG. 15, it is assumed that the pulse voltage Wb is applied at the electrical angles θ60, θ61, θ62,... With respect to the fundamental wave voltage Wa. Changes in the phase current and the dq axis current in this case are as shown in FIG. As is clear from the simulation waveform shown in FIG. 16, both the phase current and the dq axis current are greatly changed to cause an imbalance. For example, the average value of each phase current is -65 [A] for the phase current Iu, -3.8 [A] for the phase current Iv, and 68.8 [A] for the phase current Iw. As such imbalance occurs, the phase current becomes unstable, and there is a problem that the rotor cannot be excited stably.

  The present invention has been made in view of such points, and even when a pulse voltage is applied in a mode in which the modulation rate is equal to or greater than a certain value, control is performed so that the average voltage of the phase voltage becomes zero. An object of the present invention is to provide a synchronous machine that can stabilize a phase current of a phase and stably excite a rotor.

  The invention according to claim 1, which has been made in order to solve the above-described problems, includes a stator wound with an armature winding, and a rotor core wound with a field winding, and rotates against the stator. And a rectifying element that is connected in series with the field winding and regulates an induced alternating current induced in the field winding by an armature current flowing in the armature winding in one direction, and a switching element, A control signal is output to the drive unit based on any one of a sine wave mode, a rectangular wave mode, and an overmodulation mode, and a drive unit that outputs power of two or more phases to the armature winding. In the synchronous machine having a control unit, when the control unit is any one of the rectangular wave mode and the overmodulation mode, a pulse voltage for exciting the rotor is set to a fundamental voltage. Superimpose In the case, wherein the average value of each phase of the phase voltage outputs said control signal to be zero.

  The “average voltage is zero” is not limited to a mode in which the average voltage is 0 [V], but includes a mode in which the average voltage decreases and approaches 0 [V] (that is, approximately 0 [V]). “Applying a pulse voltage” means superimposing a pulse voltage for exciting a rotor (specifically, a field winding) on a fundamental wave (sine wave or pulse wave) voltage of an armature current. To do.

  According to this configuration, in any one of the rectangular wave mode and the overmodulation mode, that is, the mode in which the modulation rate is a certain value or more, the control unit makes the average voltage of the phase voltage of each phase zero. A pulse voltage is superimposed on the fundamental wave of the armature current. For example, when applying a pulse voltage that turns ON, the average voltage of the phase voltage is made zero by applying a pulse voltage that turns OFF in the opposite state. Conversely, when applying a pulse voltage that turns OFF, the average voltage of the phase voltage is made zero by applying a pulse voltage that turns ON in the reverse state. In this way, the average voltage of the phase voltage is made zero by applying a pulse voltage that is in a state opposite to the pulse voltage applied to the fundamental wave voltage. Thus, since the average voltage of the phase voltage of each phase becomes zero, the phase current of each phase can be stabilized and the rotor can be excited stably.

According to a second aspect of the present invention, when the control unit is in the rectangular wave mode, a pulse voltage for exciting the rotor at an electrical angle interval of 120 ° or 180 ° is superimposed on the fundamental wave voltage. The pulse voltage is applied so that the amplitude of the output voltage vector at that time is the same as the amplitude of the fundamental voltage vector on the dq coordinate, and the average value of the phase voltage of each phase is made zero.

According to this configuration, in the rectangular wave mode, the control unit pulses the electrical voltage at intervals of 120 ° or 180 ° so that the amplitude of the output voltage vector is the same as the amplitude of the fundamental voltage vector on the dq coordinate. Apply voltage. At an electrical angle of 120 ° or 180 °, the average voltage of each phase can be made zero without performing voltage correction or the like, so that the phase current of each phase can be stabilized and the rotor can be excited stably.

According to a third aspect of the present invention, when the control unit is in the overmodulation mode, the electrical angle is 120 ° or 180 ° during a modulation width wider than the pulse width of the pulse voltage to be applied. The pulse voltage is applied so that the amplitude of the output voltage vector is the same as the amplitude of the fundamental voltage vector on the dq coordinate when the pulse voltage for exciting the rotor is superimposed on the fundamental voltage at intervals of Thus, the average value of the phase voltage of each phase is set to zero.

According to this configuration, in the overmodulation mode, the control unit applies the pulse voltage during a period of a modulation width wider than the pulse width of the pulse voltage. This application is performed at an electrical angle of 120 ° or 180 ° so that the amplitude of the output voltage vector when superimposed on the fundamental voltage is the same as the amplitude of the fundamental voltage vector on the dq coordinate. Since the fundamental voltage and the superimposed voltage are the same voltage vector on the dq coordinate, the average voltage of the phase voltages of each phase can be made more surely zero.

According to a fourth aspect of the present invention, the control unit has an amplitude of an output voltage vector when a pulse voltage for exciting the rotor is superimposed on the fundamental voltage at an electrical angle of 120 ° or 180 °. In the pattern in which the pulse voltage is applied so as to be the same as the amplitude of the fundamental voltage vector on the dq coordinate, the pulse voltage is applied in a plurality of patterns.

According to this configuration, even when control is performed such that a plurality of pulse voltages must be applied for the purpose of increasing the excitation amount of the rotor, the application is performed in a plurality of patterns. In one pattern, a pulse voltage is applied so that an electrical angle is 120 ° or 180 ° in a specific phase. A plurality of patterns of two or more are applied while maintaining an interval of 120 ° or 180 ° in electrical angle, and the amplitude of the output voltage vector when the pulse voltage is superimposed on the fundamental voltage is It is applied so as to be the same as the amplitude of the fundamental voltage vector on the dq coordinate. In this way, a plurality of pulse voltages can be applied in one period of the fundamental voltage, so that the phase current of each phase can be further stabilized.

  In the invention according to claim 5, when the control unit applies a pulse voltage for exciting the rotor in the overmodulation mode, the control unit applies a pulse voltage in a state opposite to the pulse voltage to be applied. The pulse voltage of the pulse voltage and the pulse voltage of the fundamental wave voltage are separately applied by the sum of the pulse voltage at the time of application and the pulse width of the opposite state so that the average value of the phase voltage of each phase becomes zero. The control signal is output.

  According to this configuration, when in the overmodulation mode, the control unit controls so that the total pulse width of the pulse voltage to be applied is the same as the total pulse width of the reverse-state pulse voltage to be applied separately. . In other words, the pulse voltage in the normal state may be a combination of two or more pulse voltages, and the pulse voltage in the reverse state may be a combination of two or more pulse voltages. By this control, the pulse voltage is canceled out between the normal state and the reverse state, so that the average voltage of the phase voltage can be made zero. Therefore, the phase current of each phase can be stabilized and the rotor can be excited stably.

  According to a sixth aspect of the present invention, when the control unit is in the rectangular wave mode and performs control to superimpose a pulse voltage for exciting the rotor on the fundamental voltage, an ON period of the fundamental voltage or The control signal is output such that the OFF period is expanded or contracted by the same pulse width as the applied pulse voltage, and the average value of the phase voltage of each phase becomes zero.

  According to this configuration, the control unit expands and contracts as much as the pulse width of the pulse voltage to which the ON period or OFF period of the fundamental wave voltage is applied. That is, it expands and contracts by the pulse width of the pulse voltage to be applied. Therefore, the average voltage of the phase voltage of each phase can be made zero more reliably, and the phase current of each phase can be stabilized.

  According to a seventh aspect of the present invention, the controller is configured to provide a state of the fundamental wave voltage (ON or ON) to which a pulse voltage for exciting the rotor is applied when expanding or contracting the ON period or the OFF period of the fundamental wave voltage. It is characterized in that the period closer to the time at which (OFF) is switched is expanded and contracted.

  According to this configuration, the control unit expands and contracts by the pulse width for a period closer to the time when the state (ON or OFF) of the applied fundamental wave voltage is switched. Therefore, the average voltage of the phase voltage of each phase can be made zero more reliably, and the phase current of each phase can be stabilized.

  According to an eighth aspect of the present invention, the controller controls the state of the fundamental wave voltage (ON or ON) to which a pulse voltage for exciting the rotor is applied when expanding or contracting the ON period or the OFF period of the fundamental wave voltage. The period before and after the time when the (OFF) switches is expanded and contracted.

  According to this configuration, the control unit expands / contracts by an amount corresponding to the pulse width in one or both of the ON period and the OFF period before and after the time when the state (ON or OFF) of the applied fundamental wave voltage is switched. Therefore, the average voltage of the phase voltage of each phase can be made zero more reliably, and the phase current of each phase can be stabilized.

  According to a ninth aspect of the present invention, the control unit is in the rectangular wave mode, and a fundamental wave to which a pulse voltage is applied when performing a control to superimpose a pulse voltage for exciting the rotor on the fundamental wave voltage. Apply a pulse voltage in the opposite state to the applied pulse voltage by the same pulse width as the applied pulse voltage at a time separated from the time when the voltage state (ON or OFF) changes by the specified time. The control signal is output so that the average value of the signal becomes zero.

  According to this configuration, in the rectangular wave mode, the control unit outputs a pulse in a state opposite to the applied pulse voltage at a time separated from the time when the state of the applied fundamental wave voltage (ON or OFF) is switched by a predetermined time. The voltage is applied for the same pulse width as the applied pulse voltage. The length of the predetermined time can be arbitrarily set. Therefore, the average voltage of the phase voltage of each phase can be made zero more reliably, and the phase current of each phase can be stabilized.

According to a tenth aspect of the present invention, the control unit is based on a pulse voltage for exciting the rotor at an electrical angle of 360 ° × n ± 120 ° (n is an integer other than 0). The pulse voltage is applied to the fundamental voltage so that the amplitude of the output voltage vector when superimposed on the wave voltage is the same as the amplitude of the fundamental voltage vector on the dq coordinate, and the average value of the phase voltage of each phase is calculated. It is characterized by zero.

  According to this configuration, since the pulse voltage can be applied evenly in three phases, the average voltage of each phase can be made zero, and the phase current of each phase can be stabilized.

3 is a schematic diagram illustrating a configuration example of a synchronous machine in Embodiment 1. FIG. It is a schematic diagram which shows the radial direction cross section of a stator and a rotor. It is a schematic diagram which shows the example of an electrical connection. It is a figure which shows the example which applies a pulse voltage. It is a figure which expands and shows a part of FIG. It is a figure which shows the change of a phase current and a dq axis current. 6 is a diagram illustrating an example in which a pulse voltage is applied at 120 ° intervals in Embodiment 2. FIG. It is a figure which shows the example which applies a pulse voltage by a 180 degree space | interval. 10 is a diagram illustrating an example in which a pulse voltage is applied in Embodiment 3. FIG. 10 is a diagram illustrating an example in which a pulse voltage is applied in Embodiment 4. FIG. It is a figure which shows the example which applies a pulse voltage in the time away only for predetermined time. 10 is a diagram illustrating an example of applying a pulse voltage in Embodiment 5. FIG. It is a figure which shows the example which applies a pulse voltage at the timing different from FIG. 10 is a diagram illustrating an example of applying a pulse voltage in Embodiment 6. FIG. It is a figure which shows the example which applies a pulse voltage by a prior art. It is a figure which shows the change of a phase current and a dq-axis current in a prior art.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  Unless otherwise specified, the meaning of terms is defined as follows. “Connect” means an electrical connection. The notation “ON” means a state in which the pulse voltage is at a high level, and is synonymous with “1”, “H (high)”, and the like expressed according to positive logic. The notation “OFF” means a state in which the pulse voltage is at a low level, and is synonymous with “0”, “L (low)”, etc. expressed according to positive logic. In the drawing, the electrical angle is described as “deg”.

[Embodiment 1]
The first embodiment is an example in which the ON period and the OFF period of the fundamental voltage are expanded and contracted in the rectangular wave mode (that is, the modulation factor is 1.27 or in the vicinity thereof), and will be described with reference to FIGS. To do. In FIG. 1, the structural example of a synchronous machine is shown with a schematic diagram. In FIG. 2, the radial direction cross section of a stator and a rotor is shown with a schematic diagram. FIG. 3 is a schematic diagram showing an example of electrical connection. FIG. 4 schematically shows an example in which a pulse voltage is applied. FIG. 5 shows an enlarged part of FIG. FIG. 6 shows changes in phase current and dq-axis current with simulation waveforms.

  A synchronous machine M shown in FIG. 1 is applied as an electric motor, and includes a stator 10 (stator), a rotor 20 (rotor), a frame 30 (housing), a DC power supply 50, a drive unit 60, a control unit 70, and the like. The synchronous machine M is rotationally controlled by an armature current (phase currents Iu, Iv, Iw in the example of FIG. 1) output from the drive unit 60 in accordance with a control signal transmitted from the control unit 70. Configuration examples and functions of the DC power supply 50, the drive unit 60, and the control unit 70 will be described later.

  The stator 10 includes a stator coil 11 (armature winding), a stator core 12 and the like. The stator coil 11 is a multi-phase (for example, three-phase) phase winding wound around the stator core 12. The stator core 12 uses an electromagnet (or a permanent magnet or the like), for example, phase windings are distributedly wound. The order of winding the phase winding is arbitrary. Taking the U phase, V phase, and W phase as an example, the U phase conductor, the -V phase conductor, the W phase conductor, the -U phase conductor, the V phase conductor, and the -W phase conductor are sequentially arranged in the circumferential direction. The winding form is applicable.

  The rotor 20 rotates facing the stator 10 and includes a rotor shaft 21, a rotor coil 22 (field winding), a rotor core 23, and the like. The rotor shaft 21 is used as a main shaft (or a rotation shaft) of the synchronous machine M, and includes a detected portion 24 on a part of the outer peripheral surface. In this embodiment, magnetic salient poles are provided on the outer peripheral surface of the rotor shaft 21 as the detected portion 24 at regular intervals. The rotor core 23 uses an electromagnet (or a permanent magnet), and has a core teeth portion 23a that forms a pair of field poles (magnetic salient poles) as shown in FIG. The rotor coil 22 is wound around the core teeth portion 23a in order to easily form a field flux efficiently.

  The frame 30 fixes the stator 10 and rotatably supports the rotor 20 via a bearing or the like, and a position sensor 40 that detects the detected portion 24 and a current sensor 80 that detects a current value of each phase (FIG. 3). For example).

  The position sensor 40 is arbitrary as long as the position of the rotor 20 can be detected, but in this example, a resolver is used. The resolver transmits a signal (analog signal or digital signal) to the control unit 70 every time the detected unit 24 is detected.

  The current sensor 80 is optional as long as the armature current (that is, the phase currents Iu, Iv, Iw) can be detected. For example, a magnetic proportional sensor that uses a Hall element to detect a magnetic field generated by an armature current as a detected current is used.

  FIG. 3 shows a connection example (circuit diagram) for driving and controlling the synchronous machine M. The DC power supply 50 supplies power to the drive unit 60 via the smoothing capacitor C2. The drive unit 60 functions as an inverter, and the transistor Q and the diode D2 are set as one set, and there are six sets in total to correspond to three phases. The drive unit 60 performs switching in accordance with a control signal transmitted from the control unit 70 and outputs it to the synchronous machine M with a required power and frequency. For example, an IGBT is used as the transistor Q. Since the diode D2 serves as a freewheeling diode, the diode D2 is connected between the collector terminal and the emitter terminal of the transistor Q so that the current flows in the direction opposite to the current flowing through the transistor Q.

  The control unit 70 receives signals output from the position sensor 40 and the current sensor 80 and outputs a control signal to the drive unit 60 (specifically, the gate terminal of each transistor Q). The control unit 70 includes a normal function for driving and controlling the synchronous machine M, and a pulse voltage applying unit 71 for realizing the present invention. The configuration of the control unit 70 is arbitrary. The control unit 70 may include a CPU, a ROM, a RAM, and the like, and may be operated by executing a program, or may be operated by hardware logic formed by circuit elements.

  The pulse voltage applying means 71 has a function of outputting a control signal in which the rotor excitation current is superimposed on the fundamental wave of the armature current passed through the stator coil 11 to the drive unit 60 in the rectangular wave mode. The fundamental wave of the armature current corresponds to a synchronous current (that is, a fundamental wave component of the phase currents Iu, Iv, and Iw) that forms a rotating magnetic field that rotates according to the electrical angular rotational speed that matches the rotational speed of the rotor 20. The rotor excitation current is a current according to a pulse voltage applied at a required time, and is a component of an armature current for causing the rotor coil 22 to generate an inductive AC current. The rotor excitation current is formed based on a pulse voltage (for example, see FIG. 4 described later) by voltage control of each phase for three phases (U phase, V phase, W phase).

  Note that the rotor excitation current needs to be set so as to cause a magnetic flux change relative to the rotor coil 22 regardless of the operation of the rotor 20 (ie, rotation, stationary, etc.). As a specific setting example, a rotating magnetic field that rotates relative to the rotor 20 is formed by a rotor excitation current, or an alternating current having a frequency different from the rotor synchronization frequency is supplied to the stator coil 11. Applicable. However, when forming the former rotating magnetic field, it is set so that the rotating angular velocity of the rotating magnetic field does not match the rotor angular velocity.

  On the synchronous machine M side, the rotor coil 22 and the diode D1 are connected in series. The diode D1 corresponds to a rectifying element, and half-wave rectifies the AC voltage induced in the rotor coil 22. By connecting the diode D1, one side of the pair of core teeth portions 23a can be excited to the N pole and the other side can be excited to the S pole. Further, when a rectified rotor winding current If (corresponding to a field current) is applied to the rotor coil 22, a field flux flows in a direction opposite to the saturation magnetic flux direction of the short-circuit magnetic path. Since this field flux also flows to the stator 10 side, the amount of field flux interlinked with the stator coil 11 increases.

  In addition, you may provide the capacitor | condenser C1 connected in parallel with the diode D1, as illustrated with a dashed-two dotted line. By the smoothing action of the capacitor C1, it is possible to stabilize the excitation current flowing through the rotor coil 22 and the generated voltage.

  In the synchronous machine M configured as described above, an example in which the pulse voltage is applied to the fundamental voltage by the pulse voltage applying means 71 when the control signal transmitted from the control unit 70 to the drive unit 60 is formed is shown in FIG. Will be described with reference to FIG. In FIG. 4, the waveform of the U-phase voltage is shown in FIG. 4A, the waveform of the V-phase voltage is shown in FIG. 4B, and the waveform of the W-phase voltage is shown in FIG. Note that the voltage values and electrical angles shown in each figure are examples, and are not limited to the illustrated numerical values.

  In the example shown in FIG. 4, the pulse voltage Wp is applied to each of the two phases at the electrical angles θ1, θ2, and θ3 with respect to the fundamental wave voltage Ws. The interval between the electrical angle θ1 and the electrical angle θ2 and the interval between the electrical angle θ2 and the electrical angle θ3 are both 480 °. Specifically, a pulse voltage Wp is applied to the electrical angle θ1 for the U phase and the W phase, a pulse voltage Wp is applied to the electrical angle θ2 for the U phase and the V phase, and a pulse is applied to the electrical angle θ3 for the V phase and the W phase. A voltage Wp is applied. The U phase of the electrical angle θ1, the V phase of the electrical angle θ2, and the W phase of the electrical angle θ3 are all OFF during the pulse width PW because the fundamental wave voltage Ws is in the ON period. On the other hand, the U phase of the electrical angle θ2, the V phase of the electrical angle θ3, and the W phase of the electrical angle θ1 are all ON for the pulse width PW because the fundamental wave voltage Ws is in the OFF period.

  When the pulse voltage Wp as described above is applied to the fundamental wave voltage Ws, the phase of each phase in the interval of applying the pulse voltage Wp (960 ° in the example of FIG. 4 and simply referred to as “application interval” hereinafter). The average voltage is theoretically zero. However, when one cycle of the fundamental wave voltage Ws (360 ° in the example of FIG. 4) is viewed, the average voltage of the phase voltages of each phase may not theoretically become zero. Therefore, when applying the pulse voltage Wp, the timing when the fundamental wave voltage Ws falls (or when it rises) is adjusted so as to expand and contract by the pulse width PW of the pulse voltage Wp.

  For example, as shown in FIG. 5 (A), when the fundamental wave voltage Ws is applied to the electrical angle θ1 during the ON period, the pulse width PW of the pulse width PW is lowered when it falls at the electrical angle θ4a indicated by a two-dot chain line. Extend by an amount and fall at electrical angle θ4b. Thus, the ON period of the fundamental wave voltage Ws is extended and the OFF period is shortened. Further, as shown in FIG. 5B, when the fundamental wave voltage Ws is applied to the electrical angle θ2 during the OFF period, the pulse width PW of the pulse width PW is originally lowered at the electrical angle θ5b indicated by a two-dot chain line. Shrink by the amount and fall at the electrical angle θ5a. Thus, the ON period of the fundamental wave voltage Ws is shortened and the OFF period is extended.

  As described above, by expanding or contracting the ON period or OFF period of the fundamental wave voltage Ws, the average voltage of the phase voltage of each phase is theoretically calculated not only for the application interval of the pulse voltage Wp but also for one period of the fundamental wave voltage Ws. Can be zero. In FIGS. 5A and 5B, the timing at the time of falling is changed, but the effect is the same even if the timing at the time of rising is changed. It is optional to select either one or both of the falling time and the rising time to expand or contract the ON period or OFF period of the fundamental wave voltage Ws. When selecting both the falling time and the rising time, for example, the pulse width PW is divided into two parts (whether it is uniform or non-uniform), and is assigned to expand or contract. In order to make the average voltage of the phase voltage of each phase in a short time closer to zero, one or both of the rising time and the rising time and the rising time are close to the electrical angle of the pulse voltage Wp to be applied. It is desirable to expand or contract, or to expand or contract one or both of the rising and falling times before and after the electrical angle of the pulse voltage Wp to be applied.

  In the above embodiment, the application interval for applying the pulse voltage Wp is set to be 480 ° in electrical angle. However, the application interval is 360 ° × n ± 120 ° excluding 480 ° in electrical angle (n is 0). May be set to be one or more intervals.

  The control unit 70 outputs the control signal to the drive unit 60 using the waveforms shown in FIGS. 4 and 5 as command values, and the current change when the drive unit 60 drives the synchronous machine M is shown in FIG. Specifically, FIG. 6A shows changes in three-phase armature currents (ie, phase currents Iu, Iv, Iw), and changes in dq-axis currents (ie, d-axis current id and q-axis current iq). As shown in FIG. The fluctuation range of the armature current shown in FIG. 6A is clearly reduced as compared with FIG. 15 in the prior art. For example, the average value of each phase current is 0 [A] for the phase current Iu, 20 [A] for the phase current Iv, and 20 [A] for the phase current Iw. Similarly, the fluctuation range of the dq-axis current shown in FIG. 6 (B) is clearly reduced as compared with FIG. 16 in the prior art. Therefore, the phase currents Iu, Iv, Iw of each phase become stable and the rotor 20 can be excited stably for the amount of change in current.

  According to the first embodiment described above, the following effects can be obtained.

  Corresponding to claim 1, the synchronous machine M includes the stator 10, the rotor 20, the diode D1, the drive unit 60, and the control unit 70 (see FIGS. 1 and 3), and the control unit 70 has a modulation rate equal to or greater than a certain value. When the pulse voltage Wp for exciting the rotor 20 is superimposed on the fundamental wave voltage Ws, the control signal is output so that the average voltage of the phase voltage of each phase becomes zero. (See FIGS. 4 and 5). According to this configuration, the average voltage of the phase voltage of each phase becomes zero. That is, the average voltage of the phase voltage is set to zero by applying the pulse voltage Wp in the reverse state that is a pair of the pulse voltage Wp applied to the fundamental wave voltage Ws. Since the average voltage of the phase voltage of each phase becomes zero in this way, the fluctuation range of the phase current and the dq axis current is suppressed, the phase currents Iu, Iv, Iw of each phase are stabilized, and the rotor 20 is excited stably. Yes.

  Corresponding to claim 6, the control unit 70 is configured to expand and contract as much as the width of the pulse voltage to which the ON period or OFF period of the fundamental wave voltage Ws is applied (see FIGS. 4 and 5). According to this configuration, the ON and OFF periods of the fundamental wave voltage Ws expand and contract as much as the pulse width PW of the applied pulse voltage Wp. Therefore, the average voltage of the phase voltage of each phase can be made more surely zero, and the phase currents Iu, Iv, Iw of each phase can be stabilized. In this embodiment, the pulse voltage Wp is applied at an electrical angle interval of 480 °. However, similar effects can be obtained even when the pulse voltage Wp is applied at an electrical angle interval other than 120 ° and 180 ° intervals. .

  Corresponding to claim 7, the control unit 70 is configured to expand and contract by the pulse width for a period closer to the time when the state (ON or OFF) of the applied fundamental wave voltage Ws is switched (see FIG. 5). ). According to this configuration, the average voltage of the phase voltages of each phase in a short time can be brought closer to zero more reliably. Therefore, the phase currents Iu, Iv, Iw of each phase can be stabilized.

  Corresponding to claim 8, the control unit 70 is configured to expand and contract by an amount corresponding to the pulse width in the ON period and the OFF period before and after the time when the state (ON or OFF) of the applied fundamental wave voltage Ws is switched ( (See FIG. 5). According to this configuration, the average voltage of the phase voltages of each phase in a short time can be more reliably brought close to zero, so that the phase currents Iu, Iv, Iw of each phase become stable, and the rotor 20 can be excited stably. Yes.

Corresponding to claim 10, the control unit 70 basically uses the pulse voltage Wp for exciting the rotor 20 at an electrical angle of any one of 360 ° × n ± 120 ° (n is an integer other than 0). The pulse voltage Wp is applied to the fundamental wave voltage Ws so that the amplitude of the output voltage vector when superimposed on the wave voltage Ws is the same as the amplitude of the fundamental wave voltage vector on the dq coordinate (see FIG. 5). ). According to this configuration, since the pulse voltage can be applied evenly in three phases, the average voltage of each phase can be made zero, and the phase currents Iu, Iv, Iw of each phase can be stabilized.

[Embodiment 2]
The second embodiment is an example in which a pulse voltage is applied to the fundamental voltage in the rectangular wave mode, and will be described with reference to FIGS. 7 and 8 schematically show an example in which a pulse voltage is applied. Since the configuration of the synchronous machine M is the same as that of the first embodiment, the second embodiment will be described with respect to differences from the first embodiment. Therefore, the same elements as those used in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

The waveforms shown in FIG. 7 and FIG. 8 are examples in which the pulse voltage is applied to the fundamental voltage by the pulse voltage applying means 71 when the control signal transmitted from the control unit 70 to the drive unit 60 is formed. the amplitude of the vector is applied to the control to be the same as the amplitude of the fundamental voltage vector on the dq coordinates. FIG. 7 shows an example in which the pulse voltage application interval is 120 ° in electrical angle, and FIG. 8 shows an example in which the pulse voltage application interval is 180 ° in electrical angle. Specifically, the waveform of the U-phase voltage is shown in FIGS. 7A and 8A, the waveform of the V-phase voltage is shown in FIGS. 7B and 8B, and the waveform of the W-phase voltage is shown. Is shown in FIGS. 7C and 8C. Note that the voltage values and electrical angles shown in each figure are examples, and are not limited to the illustrated numerical values.

  First, in the example shown in FIG. 7, the pulse voltage Wp is applied to the fundamental wave voltage Ws in two phases at electrical angles θ10, θ11, θ12, θ13,. The interval between the electrical angle θ10 and the electrical angle θ11, the interval between the electrical angle θ11 and the electrical angle θ12, and the interval between the electrical angle θ12 and the electrical angle θ13 are all 120 °. Each pulse voltage Wp has the same pulse width PW.

  Specifically, a pulse voltage Wp is applied to the electrical angle θ10 for the U phase and the V phase, a pulse voltage Wp is applied to the electrical angle θ11 for the V phase and the W phase, and a pulse is applied to the electrical angle θ12 for the W phase and the U phase. A voltage Wp is applied. The U phase of the electrical angle θ10, the V phase of the electrical angle θ11, and the W phase of the electrical angle θ12 are all ON for the pulse width PW because the fundamental wave voltage Ws is in the OFF period. On the other hand, the V phase of the electrical angle θ10, the W phase of the electrical angle θ11, and the U phase of the electrical angle θ12 are all OFF for the pulse width PW because the fundamental wave voltage Ws is in the ON period. After the electrical angle θ13, one cycle from the electrical angle θ10 to the electrical angle θ13 is repeated. When such a pulse voltage Wp is applied to the fundamental wave voltage Ws, the average voltage of the phase voltage of each phase in one cycle of the fundamental wave voltage Ws is theoretically zero.

  Next, in the example shown in FIG. 8, the pulse voltage Wp is applied to specific two phases at the electrical angles θ14, θ15, θ16,... With respect to the fundamental wave voltage Ws. The interval between the electrical angle θ14 and the electrical angle θ15 and the interval between the electrical angle θ15 and the electrical angle θ16 are both 180 °. Each pulse voltage Wp has the same pulse width PW.

  The specific two phases may be arbitrarily selected from the U phase, the V phase, and the W phase, and FIG. 8 shows an example in which the U phase and the V phase are selected. Specifically, the pulse voltage Wp is applied at an electrical angle θ14 and an electrical angle θ15 in one cycle of the fundamental wave voltage Ws. The U phase of the electrical angle θ14 and the V phase of the electrical angle θ15 are both ON for the pulse width PW because the fundamental wave voltage Ws is in the OFF period. On the other hand, the V phase of the electrical angle θ14 and the U phase of the electrical angle θ15 are both OFF by the pulse width PW because the fundamental wave voltage Ws is in the ON period. After the electrical angle θ16, the application is repeated in the same manner as the electrical angle θ14 and the electrical angle θ15. When such a pulse voltage Wp is applied to the fundamental wave voltage Ws, the average voltage of the phase voltage of each phase in one cycle of the fundamental wave voltage Ws is theoretically zero.

  The control unit 70 outputs the control signal to the drive unit 60 using each waveform shown in FIGS. 7 and 8 as a command value, and the current change when the drive unit 60 drives the synchronous machine M is the simulation waveform shown in FIG. The waveform has almost the same tendency. Therefore, the phase currents Iu, Iv, Iw of each phase are stabilized for the amount of change in current, and the rotor 20 can be excited stably.

  According to the second embodiment described above, the following effects can be obtained.

Corresponding to claim 2, the control unit 70 applies a pulse voltage at intervals of 120 ° or 180 ° in electrical angle so that the amplitude of the output voltage vector is the same as the amplitude of the fundamental voltage vector on the dq coordinate. It was set as the structure (refer FIG. 7 and FIG. 8). According to this configuration, the average voltage of each phase can be made zero without correcting the voltage at an electrical angle of 120 ° or 180 °, and the phase currents Iu, Iv, Iw of each phase can be stabilized. .

  In addition, with respect to the specific two phases, the fundamental wave has an interval other than the intervals of 120 ° and 180 ° in electrical angle (for example, an interval of 480 ° in electrical angle as in the first embodiment and other application intervals). The pulse voltage Wp may be applied to the voltage Ws. Even in this case, as a result, the average voltage of the phase voltage of each phase in a predetermined cycle (for example, 2 cycles or 3 cycles or more) of the fundamental wave voltage Ws can theoretically be zero, so that the phase currents Iu, Iv and Iw can be stabilized.

[Embodiment 3]
The third embodiment is an example in which a plurality of pulse voltages are applied to one period of the fundamental wave voltage in the rectangular wave mode, and will be described with reference to FIG. FIG. 9 schematically shows an example in which a pulse voltage is applied. Since the configuration of the synchronous machine M is the same as that of the first embodiment, the third embodiment will be described with respect to differences from the first embodiment. Therefore, the same elements as those used in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

The waveform shown in FIG. 9 is an example in which the pulse voltage is applied to the fundamental voltage by the pulse voltage applying means 71 when the control signal transmitted from the control unit 70 to the drive unit 60 is formed. For example, it is performed for the purpose of increasing the excitation amount of the rotor 20, and the amplitude of the output voltage vector when the pulse voltage is superimposed on the fundamental wave voltage is controlled to be the same as the amplitude of the fundamental wave voltage vector on the dq coordinate. To do. Specifically, the waveform of the U-phase voltage is shown in FIG. 9A, the waveform of the V-phase voltage is shown in FIG. 9B, and the waveform of the W-phase voltage is shown in FIG. 9C. Note that the voltage values and electrical angles shown in each figure are examples, and are not limited to the illustrated numerical values.

  In the example shown in FIG. 9, the pulse voltage Wp is applied to each of the two phases at the electrical angles θ20, θ21, θ22, θ23,. The interval between the electrical angle θ20 and the electrical angle θ22 and the interval between the electrical angle θ21 and the electrical angle θ23 are both 180 °. On the other hand, the interval between the electrical angle θ20 and the electrical angle θ21 and the interval between the electrical angle θ22 and the electrical angle θ23 are arbitrary. Each pulse voltage Wp has the same pulse width PW.

  Specifically, the pulse voltage Wp is applied to the fundamental wave voltage Ws according to two patterns (a first pattern and a second pattern). In the first pattern for the U phase and the V phase, the pulse voltage Wp is applied at the electrical angle θ20 and the electrical angle θ22, respectively. After the electrical angle θ22, one cycle from the electrical angle θ20 to the electrical angle θ22 is repeated. In the second pattern for the V phase and the W phase, the pulse voltage Wp is applied at the electrical angle θ21 and the electrical angle θ23, respectively. After the electrical angle θ23, one cycle from the electrical angle θ21 to the electrical angle θ23 is repeated.

  The U phase of the electrical angle θ20, the V phase of the electrical angles θ21 and θ22, and the W phase of the electrical angle θ23 are all ON for the pulse width PW because the fundamental wave voltage Ws is in the OFF period. On the other hand, the V phase of the electrical angles θ20 and θ23, the W phase of the electrical angle θ21, and the U phase of the electrical angle θ22 are all OFF for the pulse width PW because the fundamental voltage Ws is in the ON period. When such a pulse voltage Wp is applied to the fundamental wave voltage Ws, the average voltage of the phase voltage of each phase in one cycle of the fundamental wave voltage Ws is theoretically zero.

  The control unit 70 outputs a control signal to the drive unit 60 using each waveform shown in FIG. 9 as a command value, and the current change when the drive unit 60 drives the synchronous machine M is almost the same as the simulation waveform shown in FIG. It becomes the waveform. Therefore, the phase currents Iu, Iv, Iw of each phase can be stabilized for the amount of change in current.

According to the third embodiment described above, corresponding to claim 4, the controller 70 applies the electrical angle while maintaining an interval of 120 ° or 180 °, and the first pattern and the second pattern (multiple patterns). The pattern is applied so that the amplitude of the output voltage vector when the pulse voltage Wp is superimposed on the fundamental voltage Ws is the same as the amplitude of the fundamental voltage vector on the dq coordinate (see FIG. 9). ). According to this configuration, not only can a plurality of pulse voltages Wp be applied in one period of the fundamental wave voltage Ws, but also a phase current of each phase can be obtained even when control that requires application of a plurality of pulse voltages Wp is performed. Iu, Iv, and Iw can be stabilized.

  In the present embodiment, the first pattern targets the U phase and the V phase, and the second pattern targets the V phase and the W phase (see FIG. 9). Which phase is targeted for each pattern can be arbitrarily set, but it is desirable to cover all phases through all patterns. Further, the number of phases to be targeted is not limited to two phases, but may be three or more phases (however, the number of phases is smaller than the total number of phases). Thus, even when the pulse voltage Wp is applied to the fundamental wave voltage Ws according to a plurality of patterns, the same effect as that of the above-described embodiment can be obtained.

  Further, the pulse voltage Wp is applied to the fundamental voltage Ws at intervals other than the intervals of 120 ° and 180 ° in electrical angle (for example, the interval of 480 ° in electrical angle as in the first embodiment and other application intervals). The pattern to be applied may be configured to apply the pulse voltage Wp to the fundamental voltage Ws in a plurality of patterns. Even in this case, the average voltage of the phase voltage of each phase in a predetermined cycle (for example, two cycles or three cycles or more) of the fundamental wave voltage Ws can be theoretically zero. Therefore, not only a plurality of pulse voltages Wp can be applied, but also the phase currents Iu, Iv, Iw of each phase can be stabilized.

[Embodiment 4]
Embodiment 4 is an example in which voltage compensation is performed together with application of a pulse voltage in the rectangular wave mode, and will be described with reference to FIG. FIG. 10 schematically shows an example of pulse voltage application and compensation. Since the configuration of the synchronous machine M is the same as that of the first embodiment, the difference from the first embodiment will be described in the fourth embodiment. Therefore, the same elements as those used in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  10 forms a control signal to be transmitted from the control unit 70 to the drive unit 60, and a pulse voltage is applied to the fundamental wave voltage by the pulse voltage applying means 71, and the fundamental wave is used for voltage compensation. This is an example of changing the voltage. Specifically, the waveform of only the fundamental wave voltage before applying the pulse voltage is shown in FIG. 10A, the waveform obtained by applying the pulse voltage to the fundamental voltage is shown in FIG. FIG. 10C shows a waveform when voltage compensation is performed after applying a pulse voltage. Note that the voltage values and electrical angles shown in each figure are examples, and are not limited to the illustrated numerical values.

  The fundamental wave voltage Ws shown in FIG. 10A has an electrical angle of 360 ° as one cycle. In this embodiment, the waveform relating to the U phase is shown, but the same applies to any of the other two phases (V phase and W phase). The application interval for applying the pulse voltage Wp corresponds to 120 °, 180 °, 360 ° × n ± 120 ° (where n is an integer other than 0). When the pulse voltage Wp is applied to the fundamental voltage Ws, the result is as shown in FIG. The electrical angle θ30 to which the pulse voltage Wp is applied is OFF by the pulse width PW because the fundamental wave voltage Ws is in the ON period. Thus, simply applying the pulse voltage Wp to the fundamental wave voltage Ws does not theoretically mean the average voltage of the phase voltage in one cycle of the fundamental wave voltage Ws. In order to make this average voltage theoretically zero, voltage compensation is performed to change the waveform of the fundamental voltage Ws.

  Specifically, for the ON period or OFF period of the fundamental wave voltage Ws, the period (ON period or OFF period) is expanded or contracted by the pulse width PW of the pulse voltage Wp to be applied. That is, the timing when the fundamental wave voltage Ws falls (or rises) is adjusted so as to expand and contract by the pulse width PW of the pulse voltage Wp. In the example shown in FIG. 10 (C), the falling time at the timing close to the electrical angle θ30 is changed, and when it falls originally at the electrical angle θ31 indicated by a two-dot chain line, the electrical power is shifted by the pulse width PW. Fall at an angle θ32. Thus, the ON period of the fundamental wave voltage Ws is extended and the OFF period is shortened.

  In the example of FIG. 10C, the falling time is applied as the time when the state of the fundamental wave voltage Ws switches, but the effect is the same even when the rising time is applied. It is optional to select either one or both of the falling time and the rising time to expand or contract the ON period or OFF period of the fundamental wave voltage Ws. When selecting both the falling time and the rising time, for example, the pulse width PW is divided into two parts (whether it is uniform or non-uniform), and is assigned to expand or contract. In order to make the average voltage of the phase voltage in a short time closer to zero, the falling or rising time close to the electrical angle of the pulse voltage Wp to be applied is expanded, or the pulse voltage Wp to be applied is It is desirable to expand and contract at the time of falling or rising before and after the electrical angle.

  The control unit 70 outputs the control signal to the drive unit 60 using each waveform shown in FIG. 10 as a command value, and the current change when the drive unit 60 drives the synchronous machine M has the same tendency as the simulation waveform shown in FIG. It becomes the waveform. Therefore, the phase currents Iu, Iv, Iw of each phase become stable and the rotor 20 can be excited stably as the current change is reduced.

  In order to perform voltage compensation, the above-described example of FIG. 10 is changed so that the ON period or OFF period of the fundamental voltage Ws is expanded or contracted. On the other hand, although it is the same in that voltage compensation is performed, the pulse voltage Wp may be applied at a time separated by a predetermined time from the time when the state (ON or OFF) of the fundamental wave voltage Ws is switched. This application example will be described with reference to FIG. In order to simplify the description, the period and voltage value of the fundamental wave voltage Ws are the same as those in FIG. That is, the fundamental wave voltage Ws shown in FIG. 11A is assumed to be the same as that in FIG. 10A, and the application timing of the pulse voltage Wp shown in FIG. 11B is also assumed to be the same as that in FIG.

  In FIG. 11C, with respect to the pulse voltage Wp applied at the electrical angle θ30 with respect to the fundamental wave voltage Ws, a predetermined time from the electrical angle θ31 at which the fundamental wave voltage Ws falls (in this example, the electrical angle is 50 °). Control is performed to apply the pulse voltage Wp in the opposite state to the electrical angle θ33 that is separated by a distance. In other words, the timing of the electrical angle θ33 can be said to be a time away from the electrical angle θ34 at which the fundamental wave voltage Ws rises by a predetermined time (in this example, 130 ° in electrical angle). The length of the predetermined time can be arbitrarily set, may be a constant value (invariable), or may be appropriately changed according to a change condition, a function expression, or the like. In any case, the pulse voltage Wp applied to the electrical angle θ33 has the same pulse width PW as the pulse voltage Wp applied to the electrical angle θ30. In this way, the pulse voltage Wp applied to the electrical angle θ30 is canceled with the reverse pulse voltage Wp applied to the electrical angle θ33. Therefore, the average voltage of the phase voltages of each phase in one cycle of the fundamental wave voltage Ws is theoretically zero.

  Although not shown, the pulse voltage Wp in the opposite state may be applied with a pulse width different from the pulse width PW of the pulse voltage Wp applied to the fundamental wave voltage Ws. For example, when the pulse width is half of the pulse voltage Wp applied to the electrical angle θ30, the pulse width is applied in two steps, that is, the electrical angle θ33 and another electrical angle (for example, 400 ° in electrical angle). The same applies when dividing into three or more times. The pulse width when applied in two or more times may be uniform or non-uniform. In any case, it is only necessary that the total pulse width of all the pulse voltages Wp in the reverse state applied in multiple times and the pulse width PW of the pulse voltage Wp applied to the electrical angle θ30 have the same width. . Even when such control is performed, as a result, the average voltage of the phase voltage of each phase in one cycle of the fundamental wave voltage Ws is theoretically zero.

  According to the fourth embodiment described above, the following effects can be obtained.

  Corresponding to claim 7, the control unit 70 is configured to expand and contract by the pulse width PW in a period closer to the time when the state (ON or OFF) of the applied fundamental wave voltage Ws is switched (see FIG. 10). reference). According to this configuration, the average voltage of the phase voltages of each phase in a short time can be brought closer to zero more reliably. Therefore, the phase currents Iu, Iv, Iw of each phase become stable, and the rotor 20 can be excited stably.

  Corresponding to claim 8, the control unit 70 is configured to expand and contract by the pulse width PW for the ON period and the OFF period before and after the time when the state (ON or OFF) of the applied fundamental wave voltage Ws is switched. . According to this configuration, the average voltage of the phase voltages of each phase in a short time can be brought closer to zero more reliably. Therefore, the phase currents Iu, Iv, Iw of each phase become stable, and the rotor 20 can be excited stably.

  Corresponding to claim 9, the control unit 70 detects a pulse voltage in a state opposite to the applied pulse voltage Wp at a time separated from the time when the state (ON or OFF) of the applied fundamental wave voltage Ws is switched by a predetermined time. Wp was applied by the same pulse width PW as the applied pulse voltage Wp (see FIG. 11). According to this configuration, since the average voltage of the phase voltages of each phase can be more reliably brought close to zero, the phase currents Iu, Iv, Iw of each phase become stable, and the rotor 20 can be excited stably.

Corresponding to claim 10, the control unit 70 basically uses the pulse voltage Wp for exciting the rotor 20 at an electrical angle of any one of 360 ° × n ± 120 ° (n is an integer other than 0). The pulse voltage Wp is applied to the fundamental wave voltage Ws so that the amplitude of the output voltage vector when superimposed on the wave voltage Ws is the same as the amplitude of the fundamental wave voltage vector on the dq coordinate (FIG. 10, FIG. 11). According to this configuration, since the pulse voltage can be applied evenly in three phases, the average voltage of each phase can be made zero, and the phase currents Iu, Iv, Iw of each phase can be stabilized.

[Embodiment 5]
Embodiment 5 is an example in which a pulse voltage is applied to the fundamental voltage in an overmodulation mode (that is, 1 ≦ modulation rate <1.27 or 1.15 ≦ modulation rate <1.27 in specific control). Therefore, description will be made with reference to FIGS. 12 and 13 schematically show an example in which a pulse voltage is applied. The difference between FIG. 12 and FIG. 13 is the timing of applying the pulse voltage. Since the configuration of the synchronous machine M is the same as that of the first embodiment, the fifth embodiment will be described with respect to differences from the first embodiment. Therefore, the same elements as those used in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  First, the waveform shown in FIG. 12 is an example in which a pulse voltage is applied to the fundamental voltage by the pulse voltage applying means 71 when the control signal transmitted from the control unit 70 to the drive unit 60 is formed. FIG. 12 shows an example in which the pulse voltage application interval is 180 ° in electrical angle. Specifically, the waveform of the U-phase voltage is shown in FIGS. 12A and 13A, the waveform of the V-phase voltage is shown in FIGS. 12B and 13B, and the waveform of the W-phase voltage is shown. Is shown in FIG. 12 (C) and FIG. 13 (C). Note that the voltage values and electrical angles shown in each figure are examples, and are not limited to the illustrated numerical values.

  In FIG. 12, the pulse voltage Wp is applied to specific two phases at electrical angles θ40, θ41, θ42,... With respect to the fundamental wave voltage Ws. The interval between the electrical angle θ40 and the electrical angle θ41 and the interval between the electrical angle θ41 and the electrical angle θ42 are both 180 °. In FIG. 13, the pulse voltage Wp is applied to specific two phases at the electrical angles θ43, θ44, θ45,... With respect to the fundamental wave voltage Ws. The interval between the electrical angle θ43 and the electrical angle θ44 and the interval between the electrical angle θ44 and the electrical angle θ45 are both 180 °. Each pulse voltage Wp has the same pulse width PW.

  The specific two phases are selected from the U phase, the V phase, and the W phase, provided that the modulation width Mw is wider (longer) than the pulse width PW of the pulse voltage Wp when the pulse voltage Wp is applied. And In the example shown in FIG. 12, at the timing of the electrical angles θ40, θ41, θ42,... Where the pulse voltage Wp is to be applied, the U phase and V phase are turned on with a modulation width Mw wider than the pulse width PW of the pulse voltage Wp. It is turned off. Therefore, the U phase and the V phase are selected. In the example shown in FIG. 13, the U phase and the W phase are turned on with a modulation width Mw wider than the pulse width PW of the pulse voltage Wp at the timing of the electrical angles θ43, θ44, θ45,. Or it is OFF. Therefore, the U phase and the W phase are selected.

  In FIG. 12, the pulse voltage Wp is applied at electrical angles θ40, θ41, θ42,... For the selected U phase and V phase. The U phase of the electrical angle θ40 and the V phase of the electrical angle θ41 are both OFF for the pulse width PW because the fundamental wave voltage Ws is in the ON period. On the other hand, the V phase of the electrical angle θ40 and the U phase of the electrical angle θ41 are both ON for the pulse width PW because the fundamental wave voltage Ws is in the OFF period. After the electrical angle θ42, the application is repeated in the same manner as the electrical angle θ40 and the electrical angle θ41. When such a pulse voltage Wp is applied to the fundamental wave voltage Ws, the average voltage of the phase voltage of each phase in one cycle of the fundamental wave voltage Ws is theoretically zero.

  In FIG. 13, the pulse voltage Wp is applied at electrical angles θ43, θ44, θ45,... For the selected U phase and W phase. The U phase of the electrical angle θ43 and the W phase of the electrical angle θ44 are both OFF by the pulse width PW because the fundamental wave voltage Ws is in the ON period. On the other hand, the W phase of the electrical angle θ43 and the U phase of the electrical angle θ44 are both ON for the pulse width PW because the fundamental wave voltage Ws is in the OFF period. After the electrical angle θ45, the mode of application is repeated similarly to the electrical angle θ43 and the electrical angle θ44. When such a pulse voltage Wp is applied to the fundamental wave voltage Ws, the average voltage of the phase voltage of each phase in one cycle of the fundamental wave voltage Ws is theoretically zero.

  Each of the waveforms shown in FIG. 12 and FIG. 13 is used as a command value, the control unit 70 outputs a control signal to the drive unit 60, and the current change when the drive unit 60 drives the synchronous machine M is the simulation shown in FIG. The waveform has the same tendency as the waveform. 12 and 13, the application interval of the pulse voltage Wp is set to 180 ° in electrical angle, but the same applies to the case where the electrical angle is set to 120 °. Therefore, the phase currents Iu, Iv, Iw of each phase become stable and the rotor 20 can be excited stably as the current change is reduced.

According to the fifth embodiment described above, corresponding to claim 3, the control unit 70 has an electrical angle interval of 120 ° or 180 ° during the period of the modulation width Mw wider than the pulse width PW of the pulse voltage Wp. The pulse voltage Wp is applied so that the amplitude of the output voltage vector when the pulse voltage Wp for exciting the rotor 20 is superimposed on the fundamental wave voltage Ws is the same as the amplitude of the fundamental wave voltage vector on the dq coordinate. It was set as the structure (refer FIG. 12 and FIG. 13). According to this configuration, the pulse voltage Wp is not applied when modulation is performed with a modulation width Mw that is narrower (shorter) than the pulse width PW of the pulse voltage Wp. Therefore, since the fundamental voltage Ws and the superimposed voltage are the same voltage vector on the dq coordinate, the average voltage of the phase voltage of each phase can be made more surely zero, and the phase currents Iu, Iv of each phase , Iw becomes stable, and the rotor 20 can be excited stably.

[Embodiment 6]
Embodiment 6 is an example in which voltage compensation is performed together with application of a pulse voltage in an overmodulation mode (ie, 1 ≦ modulation rate <1.27 or 1.15 ≦ modulation rate <1.27 in specific control). This will be described with reference to FIG. FIG. 14 schematically shows an example of pulse voltage application and compensation. Since the configuration of the synchronous machine M is the same as that of the first embodiment, the difference from the first embodiment will be described in the sixth embodiment. Therefore, the same elements as those used in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The waveform shown in FIG. 14 applies a pulse voltage to the fundamental wave voltage by the pulse voltage application means 71 and forms a fundamental wave for voltage compensation when forming a control signal transmitted from the control unit 70 to the drive unit 60. This is an example of changing the voltage. Specifically, the waveform of only the fundamental voltage before applying the pulse voltage is shown in FIG. 14A, the waveform of applying the pulse voltage to the fundamental voltage is shown in FIG. FIG. 14C shows a waveform when voltage compensation is performed after applying a pulse voltage. Note that the voltage values and electrical angles shown in each figure are examples, and are not limited to the illustrated numerical values.

  The fundamental wave voltage Ws shown in FIG. 14A has an electrical angle of 360 ° as one cycle. In this embodiment, the waveform relating to the U phase is shown, but the same applies to any of the other two phases (V phase and W phase). The application interval for applying the pulse voltage Wp is arbitrary, and corresponds to, for example, 120 °, 180 °, 360 ° × n ± 120 ° (n is an integer other than 0). When the pulse voltage Wp is applied to the fundamental voltage Ws, the waveform is as shown in FIG. The electrical angle θ52 to which the pulse voltage Wp is applied is OFF by the pulse width PW because the fundamental wave voltage Ws is in the ON period. Thus, simply applying the pulse voltage Wp to the fundamental wave voltage Ws does not theoretically mean the average voltage of the phase voltage in one cycle of the fundamental wave voltage Ws. In order to make this average voltage theoretically zero, voltage compensation is performed to change the waveform of the fundamental voltage Ws.

  Specifically, voltage compensation is performed for a width change period Cp1 in which the modulation width is changed while switching the ON / OFF of the fundamental wave voltage Ws in small increments. In the example shown in FIG. 14C, since the electrical angle θ52 is turned off by the amount corresponding to the pulse width PW, in order to compensate for this, the fundamental wave voltage Ws falls within the width change period Cp1 during which the OFF period shifts to the ON period. Turn ON for the pulse width PW. Although not shown, the fundamental wave voltage Ws may be turned on by the pulse width PW within the width change period Cp2 during which the basic period voltage Ws shifts from the ON period to the OFF period. When generalized, it is the same as applying a pulse voltage in a state opposite to the waveform obtained by applying the pulse voltage Wp to the fundamental wave voltage Ws (that is, the waveform of the electrical angle θ52) separately in the width change periods Cp1 and Cp2. It will be.

  Each of the waveforms shown in FIG. 14 is used as a command value, and the control unit 70 outputs a control signal to the drive unit 60. The current change when the drive unit 60 drives the synchronous machine M is almost the same as the simulation waveform shown in FIG. It becomes the waveform. Therefore, the phase currents Iu, Iv, Iw of each phase become stable and the rotor 20 can be excited stably as the current change is reduced.

  According to the sixth embodiment described above, corresponding to claim 5, when the control unit 70 applies the pulse voltage Wp for exciting the rotor 20, the pulse voltage in a state opposite to the pulse voltage Wp to be applied is applied. Wp is configured to be separately applied by the sum of the pulse width PW of the applied pulse voltage Wp and the pulse voltage Wp at the time of application of the pulse voltage Wp of the fundamental wave voltage Ws and the pulse width PW in the opposite state (see FIG. 14). According to this configuration, since the pulse voltage Wp to be applied is canceled out between the normal state and the reverse state, the average voltage of the entire phase voltage can be made zero, and the phase currents Iu, Iv, Iw of each phase can be reduced. Thus, the rotor 20 can be excited stably.

  In the above-described embodiment, the same pulse voltage Wp is applied to both the normal state and the reverse state. However, one or both of the normal state and the reverse state are set on the condition that the pulse width PW is the same as the whole. You may comprise with the above pulse voltage Wp. Even in this case, as a result, the normal state and the reverse state are canceled out, so that the above-described operational effects can be obtained.

[Other Embodiments]
In the above, although the form for implementing this invention was demonstrated according to Embodiment 1-6, this invention is not limited to the said form at all. In other words, various forms can be implemented without departing from the scope of the present invention. For example, the following forms may be realized.

  The first to fourth embodiments described above are applied in the rectangular wave mode, and the fifth and sixth embodiments are applied in the overmodulation mode. Instead of this form, the opposite correspondence relationship, that is, Embodiments 1 to 4 may be applied in the overmodulation mode, and Embodiments 5 and 6 may be applied in the rectangular wave mode. Even if the correspondence is reversed, the average voltage of the phase voltages can be made zero as a result. Therefore, the phase currents Iu, Iv, Iw of each phase become stable, and the rotor 20 can be excited stably.

  In Embodiment 1-6 mentioned above, all were applied to the three-phase synchronous machine M (refer FIG. 1). Instead of this form, the present invention may be applied to a multi-phase synchronous machine M having two phases or four or more phases. For example, the overmodulation mode in two phases is in the range of 1 ≦ modulation rate <1.154. Even in the synchronous machine M having the other number of phases, the average voltage of the phase voltages of the respective phases can be made zero. Therefore, the phase currents Iu, Iv, Iw of each phase become stable, and the rotor 20 can be excited stably.

  The application timing of the pulse voltage Wp shown in the first to sixth embodiments may be performed by combining two or more modes. For example, in the combination of the first embodiment and the second embodiment, the timing at which the pulse voltage Wp is applied to the fundamental wave voltage Ws at two electrical angles θ1, θ2, and θ3, respectively (see FIG. 4), The pulse voltage Wp is applied to the fundamental wave voltage Ws by superimposing the application timing (see FIG. 7) of the two phases at electrical angles θ10, θ11, θ12, θ13,. Even when two or more modes are combined in this way, as a result, the average voltage of the phase voltages of each phase can be made zero, and the phase currents Iu, Iv, Iw of each phase become stable and stable. The rotor 20 can be excited. Therefore, the effect concerning the combined form can be obtained.

  In the first to sixth embodiments described above, an IGBT is used as the transistor Q of the switching element (see FIG. 1). Instead of this form, another transistor that functions as a switching element may be used. Examples of other transistors include FETs (MOSFETs, JFETs, MESFETs, etc.), GTOs, power transistors, and the like. Even when other transistors are used, the DC input power is converted into AC power and output. Therefore, the armature winding current (phase currents Iu, Iv, Iw) using the d-axis current id and the q-axis current iq as command values. Can be output from the drive unit 60 to the synchronous machine M. In any switching element (transistor), the same effect as in the first to sixth embodiments can be obtained.

  In Embodiment 1-6 mentioned above, the resolver was used as the position sensor 40 (refer FIG. 1). Instead of this form, another position sensor may be used. As another position sensor, for example, a photoelectric detector having a disk provided with slits at regular intervals, a light emitter, a light receiver, and the like is applicable. That is, a signal (analog signal or digital signal) is transmitted to the control unit 70 based on whether or not the light emitted from the light emitter is received by the light receiver. Even with other position sensors, the rotational position of the rotor shaft 21 can be detected and a control signal can be output from the control unit 70, so that the same operational effects as in the first to sixth embodiments can be obtained.

  In the first to sixth embodiments described above, a magnetic proportional sensor is used as the current sensor 80 (see FIG. 1). Instead of this form, another current sensor capable of detecting the phase current of each phase may be used. Examples of other current sensors include an electromagnetic induction type sensor and a Faraday effect type sensor. In the electromagnetic induction type sensor, an annular core or coil is arranged around a current bus bar, and detection is performed by an induced electromotive force generated by energization of a phase current. The Faraday effect type sensor measures the rotation angle at which the direction of polarization rotates in proportion to the strength of the magnetic field when linearly polarized light enters the optical fiber arranged along the magnetic field direction. That is, current) is detected. In any current sensor, the armature current (that is, the phase currents Iu, Iv, Iw) is accurately detected and transmitted to the control unit 70, so that the same effect as in the first to sixth embodiments can be obtained. .

  In the first to sixth embodiments described above, the synchronous machine M is applied as an electric motor (see FIG. 1). It may replace with this form and may be applied to other equipment. As other equipment, for example, an AC generator for a vehicle, a generator motor for a vehicle that can perform both engine starting and power generation, and the like are applicable. In any device, the same effect as in the first to third embodiments can be obtained. When used as a generator, the drive unit 60 can only operate as a rectifier circuit, but can generate a rotor excitation current using generated power.

10 Stator (stator)
11 Stator coil (armature winding)
12 Stator core 20 Rotor (rotor)
21 Rotor shaft 22 Rotor coil (field winding)
23 Rotor core 23a Core teeth part 30 Frame (housing)
40 position sensor 50 DC power supply 60 drive unit 70 control unit 71 pulse voltage application means 80 current sensor D1 diode (rectifier element)
D2 Diode If Rotor winding current (field current)
Iu, Iv, Iw phase current (armature current)
M synchronous machine (field winding synchronous machine)
Q transistor (switching element)
Ws Fundamental voltage Wp Pulse voltage

Claims (10)

A stator wound with an armature winding;
A rotor core around which a field winding is wound, and a rotor rotating facing the stator;
A rectifying element that is connected in series with the field winding and regulates inductive alternating current induced in the field winding by an armature current flowing in the armature winding in one direction;
A drive unit that includes a switching element and outputs power of two or more phases to the armature winding;
A control unit that outputs a control signal to the drive unit based on one of the sine wave mode, the rectangular wave mode, and the overmodulation mode;
In a synchronous machine having
When the control unit superimposes a pulse voltage for exciting the rotor on a fundamental wave voltage in any one of the rectangular wave mode and the overmodulation mode, the phase voltage of each phase A synchronous machine that outputs the control signal so that an average value thereof becomes zero. When the control unit is in the rectangular wave mode, the amplitude of the output voltage vector when the pulse voltage for exciting the rotor at an electrical angle of 120 ° or 180 ° is superimposed on the fundamental voltage is dq. 2. The synchronous machine according to claim 1 , wherein the pulse voltage is applied so as to be equal to the amplitude of the fundamental wave voltage vector on the coordinates, and an average value of the phase voltage of each phase is set to zero. In the overmodulation mode, the control unit excites the rotor at an electrical angle of 120 ° or 180 ° during a modulation width wider than the pulse width of the pulse voltage to be applied. When the pulse voltage is superimposed on the fundamental wave voltage, the pulse voltage is applied so that the amplitude of the output voltage vector becomes the same as the amplitude of the fundamental wave voltage vector on the dq coordinate, and the average value of the phase voltage of each phase The synchronous machine according to claim 1, wherein zero is set to zero. The control unit is configured such that the amplitude of the output voltage vector when the pulse voltage for exciting the rotor at an electrical angle of 120 ° or 180 ° is superimposed on the fundamental wave voltage is the fundamental voltage vector vector on the dq coordinate . 4. The synchronous machine according to claim 2 , wherein the pulse voltage is applied in a plurality of patterns in the pattern in which the pulse voltage is applied so as to have the same amplitude .   When applying a pulse voltage for exciting the rotor in an overmodulation mode, the control unit applies a pulse voltage in a state opposite to the pulse voltage to be applied, a pulse width of the applied pulse voltage, and the basic voltage The control signal is output so that the average value of the phase voltage of each phase becomes zero by separately applying the sum of the pulse voltage of the wave voltage and the pulse width of the reverse state separately. The synchronous machine according to claim 1.   The control unit is in the rectangular wave mode, and when performing control to superimpose a pulse voltage for exciting the rotor on a fundamental wave voltage, a pulse of a pulse voltage applied with an ON period or an OFF period of the fundamental wave voltage 2. The synchronous machine according to claim 1, wherein the control signal is output so that an average value of phase voltages of each phase becomes zero by expanding and contracting by the same width.   The controller, when expanding or contracting the ON period or OFF period of the fundamental wave voltage, is closer to the time when the state (ON or OFF) of the fundamental wave voltage to which the pulse voltage for exciting the rotor is applied is switched. The synchronous machine according to claim 6, wherein the period is expanded and contracted.   The control unit is a period before and after the time when the state of the fundamental wave voltage (ON or OFF) to which the pulse voltage for exciting the rotor is applied is changed in expanding or contracting the ON period or the OFF period of the fundamental wave voltage. The synchronous machine according to claim 6, wherein the synchronous machine extends and contracts.   The control unit is in the rectangular wave mode, and when performing control to superimpose the pulse voltage for exciting the rotor on the fundamental wave voltage, the state of the fundamental wave voltage to which the pulse voltage is applied (ON or OFF) is Apply a pulse voltage in the opposite state to the applied pulse voltage with the same pulse width as the applied pulse voltage at a time separated from the switching time by a predetermined time so that the average value of the phase voltage of each phase becomes zero. The synchronous machine according to claim 1, wherein the control signal is output. The controller outputs an output when a pulse voltage for exciting the rotor is superimposed on a fundamental voltage at any interval of 360 ° × n ± 120 ° (n is an integer other than 0) in electrical angle. claims the amplitude of the voltage vector is applied to the pulse voltage to be the same as the amplitude of the fundamental wave voltage vector on the dq coordinate in the fundamental wave voltage, characterized in that the average value of each phase of the phase voltage to zero Item 10. The synchronous machine according to any one of Items 5 to 9.

Images