JP4155173B2 - Motor control device - Google Patents

Description

  The present invention relates to a motor control device that controls driving of two motors, and that can change the phase difference of carrier signals for two power conversion devices to perform PWM control to an arbitrary value.

  In an apparatus for driving and controlling two motors, by providing two power converters and providing a predetermined phase difference in a triangular wave (carrier signal) used to generate a PWM signal for controlling each power converter An apparatus that suppresses ripple current generated in a power converter is known (see Patent Document 1).

JP 2002-300800 A

  However, the conventional apparatus cannot change the phase difference of the triangular wave, which is a carrier signal, to an arbitrary value.

  The motor control apparatus according to the present invention includes a phase difference changing unit that changes the phase difference between the first carrier signal and the second carrier signal for the two power conversion units to perform PWM control.

  According to the motor control device of the present invention, the two power conversion means can change the phase difference between the first carrier signal and the second carrier signal for performing PWM control to an arbitrary value. Even in a motor control device using a clock that is not used, the phase difference between the two motors can be set to a desired value.

-First embodiment-
FIG. 1 is a diagram showing an overall configuration of a motor control apparatus according to a first embodiment of the present invention. Below, the example which controls the drive of the motor mounted in a hybrid electric vehicle by the motor control apparatus in 1st Embodiment is demonstrated. The first motor 1 is a vehicle driving motor, and the second motor 2 is a starting and power generation motor, each of which is a three-phase AC synchronous motor.

  The 1st power converter device 5 and the 2nd power converter device 6 are connected in parallel with DC power supply (battery) 3 and smoothing capacitor 4, respectively. The first power conversion device 5 converts the DC voltage supplied from the DC power supply 3 and the smoothing capacitor 4 into a three-phase AC voltage based on the PWM signal input from the first motor control device 7, and the first motor 1 is applied. Similarly, the second power conversion device 5 converts the DC voltage supplied from the DC power source 3 and the smoothing capacitor 4 into a three-phase AC voltage based on the PWM signal input from the second motor control device 8, Applied to the second motor 2.

The first motor control device 7 is based on a torque command value Te ^* _A input from another control device (not shown) and a phase signal sig_phase input from a carrier phase determination device 9 described later. The PWM signal for controlling 5 is generated. The second motor control device 8 controls the second power conversion device 6 based on the torque command value Te ^* _B input from another control device (not shown) and the phase signal sig_phase input from the carrier phase determination device 9. A PWM signal for control is generated.

  Based on the signal state_A indicating the operation state of the first motor 1 and the signal state_B indicating the operation state of the second motor 2, the carrier phase determination device 9 includes the first motor control device 7 and the second motor control device 8. The phase difference of the carrier signal (triangular wave) used for generating the PWM signal is determined. The determined phase difference is output to the second motor control device 8 as a phase signal sig_phase.

  FIG. 2 is a diagram showing a detailed configuration of the first motor control device 7 and the second motor control device 8. Among the components of the first motor control device 7 and the second motor control device 8, the same components are assigned the same numbers and are distinguished by alphabets (A, B). For example, a torque control unit 10A and a torque control unit 10B, which will be described later, have the same processing function, and the torque control unit 10A to which “A” is attached is a component of the first motor control device 7. The torque control unit 10 </ b> B marked with “B” is a component of the second motor control device 8. Below, only the 1st motor control apparatus 7 is demonstrated about the same component among the structures of the 1st motor control apparatus 7 and the 2nd motor control apparatus 8. FIG.

  The first motor control device 7 is an orthogonal coordinate system composed of a d-axis corresponding to the excitation current components of the currents iua, iva and iwa flowing through the first motor 1 and a q-axis corresponding to the torque current component, that is, for motor rotation. Various calculation processes are performed in the dq coordinate system that rotates synchronously. Similarly, the second motor control device 8 performs various arithmetic processes in the dq coordinate system.

  The rotational position sensor 25 is an encoder, for example, and detects the rotational position θm of the first motor 1. The phase velocity calculation unit 16A calculates the rotation phase θea of the first motor based on the rotation position signal θm from the rotation position sensor 25, and time-differentiates θm to obtain the rotation speed ωea of the first motor 1. calculate.

Operating state determining section 15A includes a rotating speed ωea calculated by the phase velocity calculation unit 16A, based on the torque command value Te ^* _A, whether the first motor 1 is performing a power running operation, performs regenerative operation And the determination result is output to the carrier phase determination device 9 as a signal state_A.

Based on the torque command value Te ^* _A of the first motor 1 and the rotational speed ωea of the first motor 1, the torque control unit 10 </ b> A determines the d-axis current command value ida ^* and the q-axis current command value of the first motor 1. iqa ^* is calculated. The torque control unit 10A calculates the current command values ida ^* and iqa ^* by referring to a map prepared in advance using the torque command value Te ^* _A and the motor rotation speed ωea as coordinate axes.

  The three-phase / dq converter 13A converts the U-phase current iua, V-phase current iva, and W-phase current iwa (= −iua-iva) detected by the current sensor 23 into the d-axis current ida and the q-axis on the dq coordinate system. It converts into the current iqa and outputs it to the current controller 12A.

Based on the current command values ida ^* and iqa ^* calculated by the torque control unit 10A and the d-axis current ida and q-axis current iqa input from the three-phase / dq conversion unit 13A, the current control unit 12A The d-axis voltage command value Vda ^* and the q-axis voltage command value Vqa ^* are calculated. Specifically, by calculating the deviation (ida ^* −ida) and (iqa ^* −iqa) between the voltage command value and the actual current, and performing PI (proportional / integral) calculation on the calculated deviation. D-axis voltage command value Vda ^* and q-axis voltage command value Vqa ^* are calculated.

The non-interference control unit 11A calculates the d-axis compensation voltage Vda_cmp and the q-axis compensation voltage Vqa_cmp in order to compensate for the speed electromotive force in the dq coordinate system and improve the responsiveness of the d-axis and q-axis currents. The adder 17A adds the d-axis voltage command value Vda ^* calculated by the current controller 12A and the d-axis compensation voltage Vda_cmp calculated by the non-interference control unit 11A to obtain a final d-axis voltage command value vdoa. ^* Is calculated, and the q-axis voltage command value Vqa ^* and the q-axis compensation voltage Vqa_cmp are added to calculate the final q-axis voltage command value vqoa ^* .

The dq / 3-phase conversion unit 14A converts the final voltage command values vdoa ^* and vqoa ^* of the d-axis and the q-axis output from the adder 17A based on the rotational phase θe of the first motor 1 into three-phase AC coordinates. The voltage command values vua ^* , vva ^* , and vwa ^{* in the system} are converted.

The synchronous PWM generation unit 21 generates a triangular wave that is a PWM carrier signal having a phase difference of 0 ° from a period timing signal ref_pwm input from a switching period reference signal generation unit 20 described later, and the generated triangular wave and dq A PWM signal for controlling the first power converter 5 is generated based on the voltage command values vua ^* , vva ^* , vwa ^* input from the / 3-phase converter 14A.

  Among the components of the second motor control device 8, the components different from the first motor control device 7 will be described. The switching cycle reference signal generator 20 generates a triangular wave cycle timing signal ref_pwm, which is a carrier signal for the synchronous PWM generator 21 and an arbitrary phase PWM generator 22 described later to generate a PWM signal, and the synchronous PWM generator 21. And output to the arbitrary phase PWM generator 22.

The arbitrary phase PWM generation unit 22 receives the phase signal sig_ input from the carrier phase determination device 9.
Based on the phase and the periodic timing signal ref_pwm input from the periodic reference signal generator 20, a triangular wave that is a PWM carrier signal is generated. This triangular wave has a phase difference indicated by the periodic timing signal ref_pwm and the phase signal sig_phase. The arbitrary phase PWM generator 22 controls the second power converter 6 based on the generated triangular wave and the voltage command values vub ^* , vvb ^* , vwb ^* input from the dq / 3-phase converter 14B. PWM signal is generated.

  FIG. 3 is a diagram illustrating the relationship among the periodic timing signal ref_pwm, the triangular wave generated by the synchronous PWM generation unit 21, the triangular wave generated by the arbitrary phase PWM generation unit 22, and the phase signal sig_phase. The cycle timing signal ref_pwm ((i) in FIG. 3) is a pulse signal, and the falling edge of the pulse is the cycle timing of the PWM carrier signal.

  The synchronous PWM generation unit 21 of the first motor control device 7 generates a triangular wave (see (ii) in FIG. 3) synchronized with the falling edge of the periodic timing signal ref_pwm. The arbitrary phase PWM generator 22 of the second motor control device 8 uses the phase (180 ° in FIG. 3) indicated by the phase signal sig_phase (see FIG. 3 (iv)) as the initial phase difference at the start of operation. A triangular wave (see (iii) in FIG. 3) is generated with reference to the falling edge of the periodic timing signal ref_pwm. Therefore, at this time, the phase difference between the triangular wave generated by the synchronous PWM generation unit 21 and the triangular wave generated by the arbitrary phase PWM generation unit 22 is 180 °.

  Here, as shown in FIG. 3, when the phase signal sig_phase output from the carrier phase determination device 9 changes, control is performed so that the phase difference is based on the changed phase signal sig_phase. That is, the arbitrary phase PWM generation unit 22 calculates the phase signal of the previous triangular wave trough ((v) in FIG. 3) and the phase signal of the current triangular wave trough ((vi) in FIG. 3). Between the current triangular wave valley ((vi) in FIG. 3) and the next triangular wave valley (in FIG. 3) so that the phase difference indicated by the phase signal sig_phase after the change is obtained. The period of the triangular wave until (viii)) ((vii) in FIG. 3) is changed. In FIG. 3, the phase difference indicated by the phase signal sig_phase is changed from 180 ° to 90 °.

  In the motor control apparatus according to the first embodiment, the period of the triangular wave is changed by changing the upper limit value of the peak of the triangular wave. That is, as shown in FIG. 3, the upper limit value of the peak of the triangular wave is changed from the upper limit value 1 to the upper limit value 2. The change of the upper limit value of the triangular wave can be realized, for example, by changing the upper limit value of the counter that generates the triangular wave. Thereby, the phase difference between the triangular wave generated by the synchronous PWM generation unit 21 and the triangular wave generated by the arbitrary phase PWM generation unit 22 can be changed from 180 ° to 90 °.

  FIG. 4 is a diagram illustrating a voltage command value input to the arbitrary phase PWM generation unit 22, a triangular wave as a carrier signal, and an output of a PWM signal generated based on a comparison between the voltage command value and the triangular wave. is there. By changing the period of the triangular wave generated by the arbitrary phase PWM generator 22, a voltage different from the voltage command value is applied to the second motor 2 in the changed portion ((i) in FIG. 4). reference).

Therefore, in the motor control device according to the first embodiment, when the cycle of the triangular wave is changed, the voltage command value in the portion where the cycle is changed is changed simultaneously with the cycle change. FIG. 5 is a diagram showing a voltage command value whose value is changed in accordance with a change in the period of the triangular wave and a PWM signal output at that time. The voltage command values vub ^* , vvb ^* , vwb ^* input from the dq / 3-phase conversion unit 14B to the arbitrary phase PWM generation unit 22 by changing (compensating) the voltage command value in accordance with the change of the triangular wave period ^. Can be applied to the second motor 2.

  As described above, according to the motor control device in the first embodiment, the phase difference between the first carrier signal and the second carrier signal for generating the PWM signal for controlling the two power conversion devices. Can be changed to any value. Thereby, even in a motor control device using clocks that are not synchronized, the phase difference between the two motors can be set to a desired value. Moreover, since the phase difference between the two carrier signals can be changed to an arbitrary value, the ripple current generated in the power converters 5 and 6 can be more effectively suppressed.

  In the motor control apparatus according to the first embodiment, the phase difference between the two carrier signals is changed by changing the period of the triangular wave that is the carrier signal. That is, since the period of the waveform of the triangular wave is changed while maintaining a similar shape, output voltage vectors are output in the same order as when the phase difference is not changed. Further, by changing the period of the triangular wave by changing the upper limit value of the counter that generates the carrier signal, the current flowing through the motor is not disturbed when the phase difference is changed.

  Moreover, according to the motor control apparatus in the first embodiment, the voltage command value for the carrier signal whose cycle has been changed is corrected, so that an appropriate voltage can be applied to the motor.

-Second Embodiment-
FIG. 6 is a diagram illustrating an overall configuration of a motor control device according to the second embodiment. The motor controller in the second embodiment is different from the motor controller in the first embodiment in the second motor controller 8a. In other words, in addition to the torque command value Te ^* _B and the phase signal sig_phase, the PWM carrier frequency command sig_frq ^* is input to the second motor control device 8a.

  FIG. 7 is a diagram showing a detailed configuration of the first motor control device 7 and the second motor control device 8a constituting the motor control device in the second embodiment. The configuration of the first motor control device 7 is the same as the configuration of the first motor control device 7 shown in FIG. Therefore, in the following, the components different from the second motor control device 8 in the configuration of the second motor control device 8a will be described in detail.

The switching cycle reference signal generation unit 20a is based on the PWM carrier frequency command sig_frq ^* input from an external device, and the triangular wave cycle timing and carrier frequency information generated by the synchronous PWM generation unit 21 and the arbitrary phase PWM generation unit 22 A signal ref_pwm having is generated.

8, (a) PWM carrier frequency command sig_frq ^*, (b) switching cycle reference signal generation unit 20a by the generated signal Ref_pwm, triangular wave generated by the (c) synchronous PWM generator 21, (d) optionally a phase It is a figure which shows the relationship between the triangular wave produced | generated by the PWM production | generation part 22, and (e) phase signal sig_phase.

The switching cycle reference signal generation unit 20a has a cycle instructed by the carrier frequency command sig_frq ^* input from the external device at the start of operation, and the time between the falling edge and the rising edge is the carrier frequency command sig_frq ^*. The rectangular wave which becomes 1/2 of the period instructed by is output. Thereafter, the following three operations (S1) to (S3) are performed for each falling edge of the rectangular wave.

(S1) When there is a change in the carrier frequency command sig_frq ^* between the time of the current falling edge ((m) in FIG. 8) and the time of the previous falling edge ((l) in FIG. 8) Changes the time from the current falling edge to the next rising edge ((h) in FIG. 8) to 1/2 of the period specified by the changed carrier frequency command sig_frq ^* . In Figure 8, the carrier frequency command Sig_frq ^* is Y [Hz] from the X [Hz], the time interval (h), has been changed to 1 / (2Y). However, the time from the current falling edge to the next falling edge remains 1 / X and is not changed (section (h) + (i) in FIG. 8).

  (S2) Time from the time of the current falling edge ((g) in FIG. 8) to the previous rising edge ((i) in FIG. 8) and the time from the previous falling edge to the previous rising edge If (h) in FIG. 8 is different, the time from the current falling edge to the next rising edge ((j) in FIG. 8) is calculated from the previous falling edge to the previous rising edge. It is set to be the same as the time ((i) in FIG. 8). Also, the time from the current falling edge to the next falling edge ((k) in FIG. 8) is twice the time from the previous falling edge to the previous rising edge ((h) in FIG. 8). Change to the time.

  (S3) If the above (S1) and (S2) are not met, a rectangular wave having the same waveform as the previous time is output.

  The synchronous PWM generator 21 of the first motor control device 7 is synchronized with the falling edge of the signal ref_pwm, and the time from the falling edge of the rectangular wave constituting the signal ref_pwm to the rising edge of the next rectangular wave (in FIG. 8). , (F), (h), (j)), a triangular wave having a period twice as long is generated (see (c) of FIG. 8).

  The arbitrary phase PWM generation unit 22 of the second motor control device 8a configures the signal ref_pwm with a triangular wave having an initial phase difference of the phase (180 ° in FIG. 8) indicated by the phase signal sig_phase at the start of operation. It generates on the basis of the falling edge of the rectangular wave (see (d) of FIG. 8). Therefore, at this time, the phase difference between the triangular wave generated by the synchronous PWM generation unit 21 and the triangular wave generated by the arbitrary phase PWM generation unit 22 is 180 °. Further, the period of the triangular wave generated by the arbitrary phase PWM generation unit 22 is set to a time twice as long as the time from the falling edge of the rectangular wave constituting the signal ref_pwm to the rising edge of the next rectangular wave.

  The synchronous PWM generator 21 and the arbitrary phase PWM generator 22 start generating a triangular wave in synchronization with the first falling edge after first detecting the rising edge of the signal ref_pwm.

Thereafter, any one of the following operations (T1) to (T4) is performed for each time point of the valley of the triangular wave.
(T1) The time from the falling edge to the rising edge of the signal ref_pwm at the time of the previous triangular wave valley ((f) in FIG. 8) and the signal at the current triangular wave valley ((o) in FIG. 8) If there is a change between the time from the falling edge of ref_pwm to the rising edge ((h) in FIG. 8), the period of the next triangular wave is changed. That is, the period of the next triangular wave (in FIG. 8) so that the position of the trough of the next triangular wave ((r) in FIG. 8) matches the position of the rising edge of the signal ref_pwm ((p) in FIG. 8). (q)) is changed.

  (T2) The next triangular wave subjected to the above-described processing of (T1) has a cycle twice as long as the time ((h) in FIG. 8) from the falling edge to the rising edge of the previous signal ref_pwm, that is, 1 / A triangular wave with Y period is output.

  (T3) When there is a change between the phase signal sig_phase at the previous trough of the triangular wave ((r) in FIG. 8) and the phase signal sig_phase at the current trough of the triangular wave ((s) in FIG. 8) The period of the next triangular wave is changed so that the phase difference between the two triangular waves becomes a phase difference based on the instruction of the phase signal sig_phase after the change. In FIG. 8, since the instruction of the phase signal sig_phase is changed from 180 ° to 270 °, the synchronous PWM generator 21 generates the next triangular wave by changing the period ((t) in FIG. 8). The phase difference between the triangular wave and the triangular wave generated by the arbitrary phase PWM generator 22 is set to 270 °.

  (T4) When not corresponding to the above (T1) to (T3), a triangular wave having a period twice as long as the time from the falling edge to the rising edge of the signal ref_pwm is output.

  According to the motor control device in the second embodiment, similarly to the motor control device in the first embodiment, the first carrier signal for generating the PWM signal for controlling the two power conversion devices. The phase difference between the second carrier signal and the second carrier signal can be changed to an arbitrary value. In addition, since the period of the first carrier signal and the second carrier signal is controlled so as to coincide with the period of the pulse signal ref_pwm serving as a reference signal for generating the first carrier signal and the second carrier signal. The frequencies of the two carrier signals can be changed in conjunction with each other.

  The present invention is not limited to the embodiment described above. For example, in the motor control device in the first embodiment, as shown in FIG. 3, the cycle of the triangular wave that is the carrier signal is changed by one cycle change, but may be changed a plurality of times. FIG. 9 is a diagram illustrating an example in which the cycle is changed twice in order to change the phase difference between two triangular waves to a specified value (180 ° → 90 °). As a result, even if the phase difference between the two carrier signals cannot be changed to a desired value by one cycle change due to the control performance of the motor control device, two carrier signals can be obtained by changing the cycle multiple times. Can be changed to a desired value.

  In the first embodiment, the phase difference between the two carrier signals is changed from 180 ° to 90 °. In the second embodiment, the phase difference between the two carrier signals is changed from 180 ° to 270 °. The phase difference to be changed is not limited to these values, and can be changed to a desired value.

  In the motor control device according to the first embodiment, an example in which the upper limit value of the counter that generates the triangular wave is changed in order to change the period of the triangular wave has been described. However, the lower limit value of the counter may be changed. . In the first and second embodiments, the phase difference between two triangular waves is changed by changing the period of one triangular wave, but the period of both triangular waves may be changed.

  The correspondence between the constituent elements of the claims and the constituent elements of the first and second embodiments is as follows. That is, the first power converter 5 is the first power converter, the second power converter 6 is the second power converter, the synchronous PWM generator 21 is the first carrier signal generator, and the arbitrary phase PWM. The generator 22 constitutes a second carrier signal generator, the arbitrary phase PWM generator 22 constitutes a phase difference changer and a voltage command value corrector, and the switching cycle reference signal generator 20a constitutes a pulse signal generator. In addition, as long as the characteristic function of this invention is not impaired, each component is not limited to the said structure.

The figure which shows the whole structure of 1st Embodiment of the motor control apparatus by this invention. The figure which shows the detailed structure of the 1st motor control apparatus 7 and the 2nd motor control apparatus 8 which comprise the motor control apparatus in 1st Embodiment. The figure which shows the relationship between the period timing signal ref_pwm, the triangular wave produced | generated by the synchronous PWM production | generation part, the triangular wave produced | generated by the arbitrary phase PWM production | generation part, and the phase signal sig_phase The figure which shows the relationship between the voltage command value, the triangular wave which is a carrier signal, and the output value based on the comparison between the voltage command value and the triangular wave when the voltage command value is not changed The figure which shows the relationship between the voltage command value which changed the value corresponding to the change of the period of the triangular wave, the triangular wave, and the output value based on the comparison between the voltage command value and the triangular wave The figure which shows the whole structure of the motor control apparatus in 2nd Embodiment. The figure which shows the detailed structure of the 1st motor control apparatus 7 and the 2nd motor control apparatus 8a which comprise the motor control apparatus in 2nd Embodiment. Indicates the relationship between the PWM carrier frequency command sig_frq ^* , the signal ref_pwm generated by the switching period reference signal generator, the triangular wave generated by the synchronous PWM generator, the triangular wave generated by the arbitrary phase PWM generator, and the phase signal sig_phase Figure In the motor control device according to the first embodiment, the signal ref_pwm when the period of the triangular wave is changed twice, the triangular wave generated by the synchronous PWM generation unit, the triangular wave generated by the arbitrary phase PWM generation unit, and , A diagram showing the relationship of the phase signal sig_phase

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... 1st motor 2 ... 2nd motor 3 ... DC power supply 4 ... Smoothing capacitor 5 ... 1st power converter 6 ... 2nd power converter 7 ... 1st motor control apparatus 8, 8a ... 2nd motor control apparatus 9 ... Carrier phase determination devices 10A, 10B ... torque control units 11A, 11B ... non-interference control units 12A, 12B ... current control units 13A, 13B ... 3-phase / dq conversion units 14A, 14B ... dq / 3-phase conversion units 15A, 15B ... Operation state determination unit 16A, 16B ... Phase / velocity calculation unit 17A, 17B ... Adder 20 ... Switching period reference signal generation unit 21 ... Synchronous PWM generation unit 22 ... Arbitrary phase PWM generation unit 23, 24 ... Current sensors 25, 26 ... Rotational position sensor

Claims (4)

A first power conversion means for converting a direct current voltage into an alternating current voltage by PWM control and applying it to the first motor;
A second power conversion means for converting a DC voltage into an AC voltage by PWM control and applying it to the second motor;
First carrier signal generating means for generating a first carrier signal for the first power conversion means to perform PWM control;
Second carrier signal generating means for generating a second carrier signal for the second power conversion means to perform PWM control;
Phase difference changing means for changing the phase difference between the first carrier signal generated by the first carrier signal generating means and the second carrier signal generated by the second carrier signal generating means;
In the phase difference change means changes the by Ri before Symbol retardation at least one of the periods to change while maintaining the similar shape of said first carrier signal and said second carrier signal, said first Motor control , wherein the cycle is changed by changing an upper limit value or a lower limit value of a counter that generates a carrier signal whose cycle is to be changed among one carrier signal and the second carrier signal. apparatus. The motor control device according to claim 1 ,
Voltage command value correction means for correcting a voltage command value for the carrier signal whose period has been changed when the period of at least one of the first carrier signal and the second carrier signal is changed by the phase difference changing means. A motor control device further comprising: A first power conversion means for converting a direct current voltage into an alternating current voltage by PWM control and applying it to the first motor;
A second power conversion means for converting a DC voltage into an AC voltage by PWM control and applying it to the second motor;
First carrier signal generating means for generating a first carrier signal for the first power conversion means to perform PWM control;
Second carrier signal generating means for generating a second carrier signal for the second power conversion means to perform PWM control;
Per To change the phase difference between the second carrier signal generated by the first carrier signal and said second carrier signal generating means is generated by said first carrier signal generating means, before Symbol first carrier A phase difference changing means for changing the phase difference by changing a period of at least one of the signal and the second carrier signal while maintaining a similar shape ;
Voltage command value correcting means for correcting a voltage command value for the carrier signal whose period has been changed when the period of at least one of the first carrier signal and the second carrier signal is changed by the phase difference changing means; ,
Motor control apparatus comprising: a. In the motor control device according to any one of claims 1 to 3 ,
Pulse signal generating means for generating a pulse signal that serves as a reference signal for generating the first carrier signal and the second carrier signal;
The first carrier signal generation means and the second carrier signal generation means each of the first carrier signal so that the period of the carrier signal matches the period of the pulse signal generated by the pulse signal generation means. Alternatively, the motor control device generates the second carrier signal.

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