JP7733694B2 - Motor control device and motor control method - Google Patents

Description

The present invention relates to a motor control device and a motor control method.

Patent Document 1 discloses a motor control device that discharges the charge on a ripple absorption capacitor using a d-axis current via a drive circuit. When discharging the charge on the ripple absorption capacitor, this motor control device feedback controls the q-axis current and d-axis current, thereby maintaining the q-axis current at zero while allowing the d-axis current to flow.

JP 2019-134550 A

However, with the above technology, for example, during periods when feedback control of the q-axis current and d-axis current is not possible, the charge in the ripple absorption capacitor cannot be discharged.

The present invention aims to provide a motor control device, etc., that can discharge the charge of a ripple absorption capacitor without performing feedback control of the q-axis current and d-axis current.

In order to solve the above problem, one aspect of the present invention is to
a drive circuit for driving the motor;
a ripple absorption capacitor connected to a power supply line of the drive circuit;
a feedback control unit that applies a first drive signal corresponding to an electrical angle to the drive circuit based on feedback control of a d-axis current and a q-axis current;
a phase voltage control unit that applies a second drive signal corresponding to a predetermined phase voltage according to an electrical angle to the drive circuit without using the feedback control;
a selection unit that alternatively selects the first drive signal or the second drive signal and provides the selected signal to the drive circuit;
Equipped with
A motor control device is provided in which, when the charge of the ripple absorption capacitor is discharged, the selection unit selects the second drive signal, and the phase voltage control unit outputs the second drive signal corresponding to the predetermined phase voltage that supplies a predetermined d-axis current to the motor.

This invention allows the charge in the ripple absorption capacitor to be discharged without performing feedback control on the q-axis current and d-axis current.

1 is a diagram illustrating a configuration of a motor control device according to a first embodiment. FIG. 2 is a diagram illustrating an example of a circuit configuration of an output section of a drive circuit. FIG. 2 is a block diagram showing the functions of a three-phase voltage control unit in the first embodiment. FIG. 10 is a diagram showing a sine map. FIG. 2 is a diagram showing waveforms of three-phase voltage values. FIG. 3 is a diagram illustrating waveforms of three-phase current values. FIG. 10 is a diagram illustrating the configuration of a motor control device according to a second embodiment. FIG. 10 is a block diagram showing the functions of a three-phase voltage control unit in the second embodiment. 10A and 10B are diagrams illustrating waveforms of three-phase voltage values affected by dead time; 10A and 10B are diagrams illustrating waveforms of three-phase current values affected by dead time; FIG. 10 is a diagram illustrating an example of a waveform of a q-axis current value affected by dead time. FIG. 10 is a diagram illustrating an example of a waveform of a d-axis current value affected by dead time. FIG. 10 is a diagram illustrating an example of a waveform of a q-axis current value in the second embodiment. FIG. 10 is a diagram illustrating an example of a waveform of a d-axis current value in the second embodiment. FIG. 10 is a diagram illustrating waveforms of three-phase voltage values indicated by a second drive signal S2 in the second embodiment. FIG. 10 is a diagram illustrating waveforms of three-phase voltage values in the second embodiment. FIG. 10 is a diagram illustrating waveforms of three-phase current values in the second embodiment. FIG. 10 is a diagram illustrating the configuration of a motor control device according to a third embodiment. FIG. 11 is a block diagram showing the functions of a phase voltage control unit in a third embodiment. FIG. 10 shows a signal generation map.

The following describes an embodiment of the present invention with reference to the drawings.

(First Example)
1 is a diagram showing the configuration of a motor control device according to a first embodiment. The motor control device according to each embodiment can be used, for example, as a device for controlling a brushless motor for an in-vehicle electric power steering (EPS), but its use is arbitrary. For example, the motor control device according to each embodiment can be widely applied to the control of brushless motors used as power sources for two-wheeled electric vehicles and other brushless motors.

As shown in FIG. 1, the motor control device of the first embodiment includes a drive circuit 10, a ripple absorption capacitor C, a feedback control unit 20, a three-phase-two-axis conversion unit 21 (an example of a detection unit), a three-phase voltage control unit 30 (an example of a phase voltage control unit), and a selection unit 40.

The drive circuit 10 drives a three-phase brushless motor M, designated U, V, and W. The drive circuit 10 is connected to a power supply device 11 (e.g., an on-board battery) via a power supply line L and a switch SW.

The ripple absorption capacitor C is connected between the power supply line L of the drive circuit 10 and ground, and has functions such as lowering the power supply impedance to the drive circuit 10.

The feedback control unit 20 provides the drive circuit 10 with a first drive signal S1 corresponding to the electrical angle based on feedback control of the d-axis current and q-axis current.

The three-phase voltage control unit 30 provides the drive circuit 10 with a second drive signal S2 corresponding to a predetermined phase voltage according to the electrical angle, without using feedback control by the feedback control unit 20. The second drive signal S2 is a signal indicating phase voltages that are mutually phase-shifted by 120° between the three phases U, V, and W.

The selection unit 40 alternatively selects either the first drive signal S1 or the second drive signal S2 and provides it to the drive circuit 10.

As shown in FIG. 1, the feedback control unit 20 includes a PI (proportional-integral) calculation unit 22 that receives the q-axis current value and d-axis current value output from the three-phase-two-axis conversion unit 21, and a two-axis-three-phase conversion unit 23.

The three-phase-two-axis conversion unit 21 converts the U-phase current value Iu, V-phase current value Iv, and W-phase current value Iw obtained by the current detection unit 51 into a q-axis current value and a d-axis current value based on the electrical angle θ of the brushless motor M obtained by the angle detection unit 52.

As shown in FIG. 1, the PI calculation unit 22 receives a target q-axis current value and a target d-axis current value. The PI calculation unit 22 uses PI calculation to output a q-axis voltage value and a d-axis voltage value that bring the q-axis current value and the d-axis current value input from the three-phase-two-axis conversion unit 21 closer to the target q-axis current value and the target d-axis current value.

The two-axis to three-phase conversion unit 23 converts the q-axis voltage value and d-axis voltage value input from the PI calculation unit 22 into three-phase voltage values of U, V, and W based on the electrical angle θ of the brushless motor M acquired by the angle detection unit 52.

Figure 1A shows an example circuit configuration of the output section of the drive circuit.

In the example shown in FIG. 1A, a pair of semiconductor switches SU1 and SU2, a pair of semiconductor switches SV1 and SV2, and a pair of semiconductor switches SW1 and SW2 corresponding to the U, V, and W phases are connected in series between ground and power supply line L. Furthermore, the U, V, and W phase terminals of brushless motor M are connected to the midpoints of each pair of semiconductor switches SU1 and SU2, semiconductor switches SV1 and SV2, and semiconductor switches SW1 and SW2, respectively.

A pulse-width modulated signal corresponding to the first drive signal S1 or the second drive signal S2 is input to each pair of semiconductor switches SU1, SU2, semiconductor switches SV1, SV2, and semiconductor switches SW1, SW2.

Next, we will explain the operation of the motor control device of the first embodiment.

During normal operation of the brushless motor M, the switch SW is closed and power is supplied from the power supply unit 11 to the drive circuit 10 via the power supply line L.

The selector 40 also selects the first drive signal S1, which indicates the three-phase voltage value calculated by the two-axis-to-three-phase converter 23, and the first drive signal S1 is input to the drive circuit 10. Therefore, the drive circuit 10 supplies the brushless motor M with the three-phase voltage value corresponding to the first drive signal S1.

At this time, the feedback control unit 20 performs feedback control based on the q-axis current value and d-axis current value obtained from the three-phase-two-axis conversion unit 21. In other words, the feedback control unit 20 feedback controls the three-phase voltage values so that the q-axis current value and d-axis current value approach the target q-axis current value and target d-axis current value.

As a result, during normal operation of the brushless motor M, the rotation of the brushless motor M is controlled so that the q-axis current value and d-axis current value approximately match the target q-axis current value and target d-axis current value.

On the other hand, when discharging the charge in the ripple absorption capacitor C, the switch SW is opened and the power supply line L is disconnected from the power supply unit 11.

The selector 40 also selects the second drive signal S2, which indicates the phase voltage values output from the three-phase voltage controller 30, and the second drive signal S2 is input to the drive circuit 10. Therefore, the drive circuit 10 supplies the brushless motor M with the three-phase voltage values corresponding to the second drive signal S2 without relying on feedback control by the feedback controller 20.

The timing of discharging the charge from the ripple absorption capacitor C is arbitrary, but it may be discharged, for example, at the start of normal operation of the brushless motor M, after the start of normal operation, or when inspecting the brushless motor M.

Figure 2 is a block diagram showing the functions of the three-phase voltage control unit.

As shown in FIG. 2, the three-phase voltage control unit 30 functionally includes a three-phase electrical angle generation unit 31, a phase control unit 32, a sine map 33, and an amplifier 34.

The three-phase electrical angle generation unit 31 generates three-phase electrical angles based on the electrical angle θ detected by the angle detection unit 52.

Figure 3 shows a sine map.

In the example shown in Figure 3, the sine map 33 shows the relationship between the torque constant and the electrical angle θ for each of the U, V, and W phases. Note that while Figure 3 shows the relationship between the torque constant and the electrical angle θ for all three phases, it may also show this relationship for only one phase. In the latter case, the relationship between the torque constant and the electrical angle θ for all three phases can be obtained by shifting this relationship by 120°.

Next, the operation of the three-phase voltage control unit 30 will be explained.

As shown in FIG. 2, the three-phase electrical angle generation unit 31 generates three-phase electrical angles based on the electrical angle θ detected by the angle detection unit 52. These three-phase electrical angles correspond to the phases of the U, V, and W phases indicated by the sine map 33.

As shown in FIG. 2 , the three-phase electrical angles generated by the three-phase electrical angle generation unit 31 are input to the phase control unit 32. A delay phase of 90° is also provided to the phase control unit 32, which outputs three-phase electrical angles that are 90° delayed from the three-phase electrical angles generated by the three-phase electrical angle generation unit 31. The three-phase electrical angles delayed by 90° by the phase control unit 32 are provided to a sine map 33, and a three-phase sine wave delayed by 90° from the sine wave shown in the sine map 33 is input to the amplifier 34. The amplitude of the three-phase sine waves (three-phase voltage values) delayed by 90° are controlled by the amplifier 34, and the three-phase sine waves are output from the amplifier 34 as a second drive signal S2.

Figure 3A shows waveforms of three-phase voltage values, and Figure 3B shows waveforms of three-phase current values.

As is clear from a comparison with Figure 3, the three-phase sine waves U, V, and W shown in Figure 3A are each delayed by 90° from the three-phase sine waves U, V, and W shown in Figure 3. The phase of the phase voltage values shown in Figure 3A corresponds to the phase of the d-axis current, and the phase current values shown in Figure 3B also show waveforms corresponding to this. As a result, the charge in the ripple absorption capacitor C can be discharged via the brushless motor M without generating torque from the brushless motor M.

As shown in FIG. 2, the amplifier 34 is provided with an amplitude A that defines the amplitude of the phase voltage value output from the amplifier 34, and the amplifier 34 outputs a second drive signal S2 whose amplitude of the phase voltage value is amplitude A. Because amplitude A is reflected in the d-axis current value, it can be determined according to the discharge time of the charge in the ripple absorption capacitor C. For example, if it is desired to increase the d-axis current value and shorten the discharge time, amplitude A can be set to a larger value.

According to the first embodiment, it is possible to prevent the brushless motor M from inadvertently generating torque when the charge in the ripple absorption capacitor C is being discharged. For example, when the brushless motor M is used as a power source for a two-wheeled electric vehicle, it is possible to prevent unintended movement of the vehicle when the charge in the ripple absorption capacitor C is being discharged.
Furthermore, the technology disclosed in JP 2019-134550 A requires a current detection sensor for feedback control of the q-axis current and the d-axis current during d-axis discharge. Therefore, if the current detection sensor fails, for example, when applied to an electric power steering motor, self-steering or vibration may occur during discharge. However, in this embodiment, even if a current detection sensor (e.g., current detection unit 51) fails, such behavior does not occur, and safe discharge is possible. Furthermore, in the technology disclosed in JP 2019-134550 A, even if the electric power steering motor transitions to discharge processing while in operation, a current detection sensor is required for feedback control of the q-axis current and the d-axis current during d-axis discharge. Therefore, a similar behavior may occur due to a current detection sensor failure. However, in this embodiment, even if a current detection sensor fails, such behavior does not occur, and safe discharge is possible.

In addition, the charge in the ripple absorption capacitor C can be discharged without relying on feedback control by the feedback control unit 20. Therefore, the charge in the ripple absorption capacitor C can be discharged even when feedback control of the q-axis current and d-axis current by the feedback control unit 20 is not possible.

(Second Example)
The motor control device of the second embodiment will now be described.

Figure 4 shows the configuration of the motor control device of the second embodiment.

As shown in Figure 4, the motor control device of the second embodiment has a three-phase voltage control unit 30A instead of the three-phase voltage control unit 30 in the first embodiment. The other configuration is the same as in the first embodiment, so a description will be omitted.

Figure 5 is a block diagram showing the functions of the three-phase voltage control unit in the second embodiment.

As shown in FIG. 5, the three-phase voltage control unit 30A functionally includes the configuration of the three-phase voltage control unit 30, as well as a current feedback control unit 35 and a phase control unit 32A.

As shown in Figures 4 and 5, the current feedback control unit 35 receives the target q-axis current value and the q-axis current value output from the three-phase-two-axis conversion unit 21. The current feedback control unit 35 provides a feedback signal based on the target q-axis current value and the q-axis current value to the phase control unit 32A.

Next, we will explain the operation of the motor control device of the second embodiment.

As in the first embodiment, during normal operation of the brushless motor M, the switch SW is closed and power is supplied from the power supply device 11 to the drive circuit 10 via the power supply line L.

The selector 40 also selects the first drive signal S1, which indicates the three-phase voltage value calculated by the two-axis-to-three-phase converter 23, and the first drive signal S1 is input to the drive circuit 10. Therefore, the drive circuit 10 supplies the brushless motor M with the three-phase voltage value corresponding to the first drive signal S1.

As in the first embodiment, the feedback control unit 20 feedback controls the three-phase voltage values so that the q-axis current value and the d-axis current value approach the target q-axis current value and the target d-axis current value. As a result, during normal operation of the brushless motor M, the rotation of the brushless motor M is controlled so that the q-axis current value and the d-axis current value approximately match the target q-axis current value and the target d-axis current value.

Furthermore, when discharging the charge in the ripple absorption capacitor C, as in the first embodiment, the switch SW is opened and the power supply line L is disconnected from the power supply device 11. The selection unit 40 also selects the second drive signal S2 indicating the phase voltage values output from the three-phase voltage control unit 30A, and the second drive signal S2 is input to the drive circuit 10. Therefore, the drive circuit 10 supplies the three-phase voltage values corresponding to the second drive signal S2 to the brushless motor M without relying on feedback control by the feedback control unit 20.

In the second embodiment, the three-phase voltage control unit 30A controls the phases of the three-phase voltage values so that the q-axis current value approaches the target q-axis current value. Specifically, the current feedback control unit 35 provides the target q-axis current value and a feedback signal based on the q-axis current value to the phase control unit 32A. The phase control unit 32A feedback controls the q-axis current value by further adjusting the phases of the three-phase voltage values delayed by 90° by the phase control unit 32. Setting the target q-axis current value to zero allows the torque of the brushless motor M to be stably suppressed to a small value.

In contrast, in the first embodiment, the operation timing of the drive circuit 10 includes dead time, and the dead time may have a significant effect on the three-phase current.

That is, in the configuration shown in FIG. 1A, to prevent a temporary short circuit between ground and the power supply line L, a time period called dead time may be set in which both semiconductor switches SU1 and SU2 are open. The same applies to semiconductor switches SV1 and SV2 and semiconductor switches SW1 and SW2.

Figure 6 is a diagram illustrating waveforms of three-phase voltage values affected by dead time, Figure 6A is a diagram illustrating waveforms of three-phase current values affected by dead time, Figure 7 is a diagram illustrating waveforms of q-axis current values affected by dead time, and Figure 7A is a diagram illustrating waveforms of d-axis current values affected by dead time.

When the impact of dead time is significant, the three-phase voltage values decrease and exhibit a distorted waveform, as shown in Figure 6. In Figure 6, curve 61U indicates the U-phase voltage value actually applied to brushless motor M, and curve 62U indicates the U-phase voltage value indicated by second drive signal S2, or in other words, the target U-phase voltage value. The V-phase and W-phase indicate the phase voltage values actually applied to brushless motor M.

Furthermore, as shown in Figure 6A, distortion occurs in the three-phase current values. In the example of Figure 6A, the section of electrical angle θ where the phase current values are essentially zero due to the dead time is expanded compared to Figure 3B.

Furthermore, as shown in Figure 7, a q-axis current value is generated, and a torque corresponding to the q-axis current according to the electrical angle θ is generated in the brushless motor M. Furthermore, as shown in Figure 7A, fluctuations also occur in the d-axis current value according to the electrical angle θ.

In contrast, in the second embodiment, feedback control of the q-axis current means that substantially no q-axis current is generated, and no torque is generated in the brushless motor M.

Figure 8 shows an example of the waveform of the q-axis current value in the second embodiment, and Figure 8A shows an example of the waveform of the d-axis current value in the second embodiment.

As shown in Figure 8, in the second embodiment, feedback control of the q-axis current results in virtually no q-axis current. Therefore, no torque is generated in the brushless motor M. Also, as shown in Figure 8A, the d-axis current value does not fluctuate according to the electrical angle θ, and the d-axis current value remains approximately constant.

Figure 9 is a diagram illustrating the waveforms of the three-phase voltage values indicated by the second drive signal S2 in the second embodiment, Figure 9A is a diagram illustrating the waveforms of the three-phase voltage values in the second embodiment, and Figure 9B is a diagram illustrating the waveforms of the three-phase current values in the second embodiment.

As shown in Figure 9, in the second embodiment, as a result of feedback control of the q-axis current, the three-phase voltage values indicated by the second drive signal S2 are corrected so that the effects of dead time are canceled. Therefore, as shown in Figure 9A, distortion in the three-phase voltage values applied to the brushless motor M is eliminated, and distortion in the three-phase current values is also eliminated.

According to the second embodiment, it is possible to prevent the brushless motor M from inadvertently generating torque when the ripple absorption capacitor C is discharging. For example, when the brushless motor M is used as a power source for a two-wheeled electric vehicle, it is possible to prevent unintended vehicle movement when the ripple absorption capacitor C is discharging. In particular, the second embodiment can effectively suppress the influence of dead time included in the operation timing of the drive circuit 20. Therefore, it is possible to appropriately manage the torque in the brushless motor M when the ripple absorption capacitor C is discharging.
Furthermore, the technology disclosed in JP 2019-134550 A requires a current detection sensor for feedback control of the q-axis current and the d-axis current during d-axis discharge. Therefore, if the current detection sensor fails, for example, when applied to an electric power steering motor, self-steering or vibration may occur during discharge. However, in this embodiment, even if a current detection sensor (e.g., current detection unit 51) fails, such behavior does not occur, and safe discharge is possible. Furthermore, in the technology disclosed in JP 2019-134550 A, even if the electric power steering motor transitions to discharge processing while in operation, a current detection sensor is required for feedback control of the q-axis current and the d-axis current during d-axis discharge. Therefore, a similar behavior may occur due to a current detection sensor failure. However, in this embodiment, even if a current detection sensor fails, such behavior does not occur, and safe discharge is possible.

In addition, the charge in the ripple absorption capacitor C can be discharged without relying on feedback control by the feedback control unit 20. Therefore, the charge in the ripple absorption capacitor C can be discharged even when feedback control of the q-axis current and d-axis current by the feedback control unit 20 is not possible.

(Third Example)
The motor control device of the third embodiment will now be described.

Figure 10 shows the configuration of the motor control device of the third embodiment.

As shown in Figure 10, the motor control device of the third embodiment has a three-phase voltage control unit 30B instead of the three-phase voltage control unit 30A in the second embodiment. The other configuration is the same as in the first and second embodiments, so a description will be omitted.

Figure 11 is a block diagram showing the functions of the phase voltage control unit in the third embodiment.

As shown in FIG. 11, the three-phase voltage control unit 30B functionally replaces part of the configuration of the three-phase voltage control unit 30A with a signal generation map 36. In other words, the signal generation map 36 essentially has the functions replaced by the phase control unit 32, current feedback control unit 35, phase control unit 32A, and sin map 33 in the second embodiment.

Figure 12 shows the signal generation map.

As shown in Figure 12, the signal generation map 36 is a map that shows the relationship between three-phase voltage values and the electrical angle θ.

In the second embodiment, the three-phase electrical angles output from the three-phase electrical angle generator 31 are provided to the signal generation map 36, which then outputs a second drive signal indicating three-phase voltage values (FIG. 12) corresponding to the electrical angle θ. Note that the function corresponding to the three-phase electrical angle generator 31 may be omitted from the three-phase voltage control unit 30B, and the electrical angle θ may be input directly to the signal generation map 36.

As can be seen by comparing the signal generation map 36 shown in Figure 12 with Figure 9, the signal generation map 36 can generate a second drive signal S2 that indicates three-phase voltage values similar to those in the second embodiment. In the third embodiment, feedback control of the d-axis current value is not performed, so when the rotational speed of the brushless motor M ranges over a wide range, it is difficult to accurately set the d-axis current value to zero using only a single signal generation map 36. However, for example, if conditions are met, such as the brushless motor M not rotating at high speed when discharging the charge of the ripple absorption capacitor C, the signal generation map 36 can effectively suppress the d-axis current value, i.e., the torque in the brushless motor M. Note that multiple signal generation maps 36 may be used depending on conditions such as the rotational speed of the brushless motor M.

According to the third embodiment, it is possible to prevent the brushless motor M from inadvertently generating torque when the ripple absorption capacitor C is discharging. For example, when the brushless motor M is used as a power source for a two-wheeled electric vehicle, it is possible to prevent unintended vehicle movement when the ripple absorption capacitor C is discharging. In particular, the second embodiment can effectively suppress the influence of dead time included in the operation timing of the drive circuit 20. Therefore, it is possible to appropriately manage the torque in the brushless motor M when the ripple absorption capacitor C is discharging.
Furthermore, the technology disclosed in JP 2019-134550 A requires a current detection sensor for feedback control of the q-axis current and the d-axis current during d-axis discharge. Therefore, if the current detection sensor fails, for example, when applied to an electric power steering motor, self-steering or vibration may occur during discharge. However, in this embodiment, even if a current detection sensor (e.g., current detection unit 51) fails, such behavior does not occur, and safe discharge is possible. Furthermore, in the technology disclosed in JP 2019-134550 A, even if the electric power steering motor transitions to discharge processing while in operation, a current detection sensor is required for feedback control of the q-axis current and the d-axis current during d-axis discharge. Therefore, a similar behavior may occur due to a current detection sensor failure. However, in this embodiment, even if a current detection sensor fails, such behavior does not occur, and safe discharge is possible.

In addition, the charge in the ripple absorption capacitor C can be discharged without relying on feedback control by the feedback control unit 20. Therefore, the charge in the ripple absorption capacitor C can be discharged even when feedback control of the q-axis current and d-axis current by the feedback control unit 20 is not possible.

As explained above, according to the first to third embodiments, the charge in the ripple absorption capacitor C can be discharged without relying on feedback control by the feedback control unit 20. Therefore, even when feedback control of the q-axis current and d-axis current by the feedback control unit 20 is not possible, the charge in the ripple absorption capacitor C can be discharged. Furthermore, when the charge in the ripple absorption capacitor C is discharged, the torque in the brushless motor M can be appropriately managed.

The above describes in detail an embodiment of the present invention with reference to the drawings, but the specific configuration is not limited to this embodiment and includes designs that do not deviate from the gist of the present invention.

The following additional notes are provided regarding the above-described embodiments of the present invention.

[Appendix 1]
a drive circuit (10) for driving a motor (M);
a ripple absorption capacitor (C) connected to the power supply line (L) of the drive circuit;
a feedback control unit (20) that provides the drive circuit with a first drive signal (S1) that corresponds to an electrical angle based on feedback control of a d-axis current and a q-axis current;
a phase voltage control unit (30, 30A, 30B) that applies a second drive signal (S2) corresponding to a predetermined phase voltage according to an electrical angle to the drive circuit without using the feedback control;
a selection unit (40) that alternatively selects the first drive signal or the second drive signal and provides the selected signal to the drive circuit;
Equipped with
a motor control device in which, when the charge of the ripple absorption capacitor is discharged, the selection unit selects the second drive signal, and the phase voltage control unit outputs the second drive signal corresponding to the predetermined phase voltage that supplies a predetermined d-axis current to the motor.

According to the configuration described in Appendix 1, when the ripple absorption capacitor discharges, the phase voltage control unit outputs a second drive signal corresponding to a predetermined phase voltage that supplies a predetermined d-axis current to the motor, allowing the ripple absorption capacitor to discharge without performing feedback control of the q-axis current and d-axis current.

[Appendix 2]
a detection unit (21) that detects a current value of a q-axis current when the second drive signal is selected by the selection unit,
2. The motor control device according to claim 1, wherein the phase voltage control unit feedback-controls the phase of the second drive signal based on the current value of the q-axis current detected by the detection unit.

The configuration described in Appendix 2 feedback-controls the phase of the second drive signal based on the current value of the q-axis current, thereby enabling appropriate management of the torque in the motor.

[Appendix 3]
the phase voltage control unit generates the second drive signal based on a signal generation map;
2. The motor control device according to claim 1, wherein the signal generation map defines a relationship between the electrical angle and the value of the second drive signal so as to suppress a current value of a q-axis current.

With the configuration described in Appendix 3, the current value of the q-axis current is suppressed by the signal generation map, thereby appropriately suppressing the torque in the motor.

[Appendix 4]
4. The motor control device according to claim 2, wherein the operation timing of the drive circuit includes a dead time.

The configuration described in Appendix 4 makes it possible to manage the q-axis current generated due to dead time, thereby enabling appropriate management of motor torque.

[Appendix 5]
a feedback control step of providing a first drive signal corresponding to an electrical angle to a drive circuit that drives the motor based on feedback control of the d-axis current and the q-axis current;
a phase voltage control step of applying a second drive signal corresponding to a predetermined phase voltage according to an electrical angle to the drive circuit without using the feedback control;
a selection step section that alternatively selects the first drive signal or the second drive signal and provides the selected signal to the drive circuit;
Equipped with
a phase voltage control step of outputting the second drive signal corresponding to the predetermined phase voltage that supplies a predetermined d-axis current to the motor when a ripple absorption capacitor connected to a power supply line of the drive circuit is discharging;

According to the configuration described in Appendix 5, when the ripple absorption capacitor discharges, the phase voltage control unit outputs a second drive signal corresponding to a predetermined phase voltage that supplies a predetermined d-axis current to the motor. This allows the ripple absorption capacitor to discharge without performing feedback control of the q-axis current and d-axis current.

10 Drive circuit 20 Feedback control section 21 Three-phase-two-axis conversion section 30, 30A, 30B Three-phase voltage control section 40 Selection section C Ripple absorption capacitor L Power supply line S1 First drive signal S2 Second drive signal

Claims (5)

a drive circuit for driving the motor;
a ripple absorption capacitor connected to a power supply line of the drive circuit;
a feedback control unit that applies a first drive signal corresponding to an electrical angle to the drive circuit based on feedback control of a d-axis current and a q-axis current;
a phase voltage control unit that supplies a second drive signal corresponding to a predetermined phase voltage and different from the first drive signal to the drive circuit;
a selection unit that alternatively selects the first drive signal or the second drive signal and provides the selected signal to the drive circuit;
Equipped with
when the charge of the ripple absorption capacitor is discharged, the selection unit selects the second drive signal, and the phase voltage control unit outputs the second drive signal corresponding to the predetermined phase voltage that supplies a d-axis current to the motor according to an electrical angle detected during the discharge of the charge;
A motor control device wherein the phase of the predetermined phase voltage value corresponds to the phase of the d-axis current . a detection unit that detects a current value of a q-axis current when the second drive signal is selected by the selection unit,
The motor control device according to claim 1 , wherein the phase voltage control unit feedback-controls the phase of the second drive signal based on the current value of the q-axis current detected by the detection unit. the phase voltage control unit generates the second drive signal based on a signal generation map;
The motor control device according to claim 1 , wherein the signal generation map defines a relationship between the electrical angle and the value of the second drive signal so as to suppress a current value of a q-axis current. A motor control device as described in claim 2 or claim 3, wherein the operation timing of the drive circuit includes dead time. a feedback control step of providing a first drive signal corresponding to an electrical angle to a drive circuit that drives the motor based on feedback control of the d-axis current and the q-axis current;
a phase voltage control step of applying a second drive signal corresponding to a predetermined phase voltage according to an electrical angle to the drive circuit;
a selection step of alternatively selecting the first drive signal or the second drive signal different from the first drive signal and providing the selected signal to the drive circuit;
Equipped with
When a ripple absorption capacitor connected to a power supply line of the drive circuit is discharging, the selecting step selects the second drive signal, and the phase voltage control step outputs the second drive signal corresponding to the predetermined phase voltage that supplies a d-axis current to the motor according to an electrical angle detected during the discharging of the charge ;
A motor control method , wherein the phase of the predetermined phase voltage value corresponds to the phase of the d-axis current .