Motor control device

Abstract

To provide a motor control device with a power source regeneration function which suppresses a rise of a DC voltage with respect to sudden large regenerative power with a little switching loss without being affected by a power supply voltage.SOLUTION: A motor control device with a power source regeneration function comprises a converter circuit, an inverter circuit and a converter control unit by which, in a case where it is detected that a DC voltage of DC power is equal to or higher than a regenerative operation reference voltage which is higher than a voltage peak value of AC power from a multiphase power source just by a first predetermined value, switching of the converter circuit is controlled for regenerating power from a motor to the multiphase power source. The converter control unit includes a voltage rise detection section and a timing compensator. In a case where it is detected that the DC voltage of DC power is equal to or higher than the regenerative operation reference voltage by a second predetermined value or more, the voltage rise detection section outputs a voltage rise signal, and the timing compensator generates a voltage reference type timing signal for the converter circuit on the basis of the voltage rise signal.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a motor control device.

Background Art

[0002] A motor control device with a power regeneration function is composed of a converter, a smoothing capacitor, and an inverter. When performing the power running operation of the motor, the converter converts AC power into DC power, and the inverter converts DC power into AC power to drive the motor. When performing the regeneration operation of the motor, the AC power generated by the motor is converted into DC power by the inverter, and the converter converts the DC power into AC power to regenerate it to the power supply.

[0003] In the converter of a motor control device with a power regeneration function, power regeneration in a 120° conduction mode is often adopted from the cost aspect. In the power regeneration in the 120° conduction mode, when the AC power generated by the motor is converted into DC power through the inverter, the voltage of the DC part of the converter increases. When the voltage of the DC part becomes higher than the peak value of the full-wave rectified voltage of the power supply voltage by a predetermined voltage, the regeneration operation is performed. Specifically, in the 120° section where the voltage of each phase of the power supply voltage is high, the switching element of the converter of each phase is turned on to regenerate current to the power supply. In such a motor control device with a power regeneration function, when the regeneration power from the motor is small, the on / off of the switching element of the converter during the regeneration operation is repeated, so the DC voltage is likely to fluctuate.

[0004] For example, Patent Document 1 discloses a rectifier including a main circuit section that performs power conversion between the AC power on the three-phase AC power supply side and the DC power on the DC part side, a power calculation section that calculates the power flowing between the three-phase AC power supply and the DC part via the main circuit section, and a control section that controls the on / off operation of the switching element of the main circuit section. The control section changes the length of the on-period per cycle in the on / off operation of the switching element according to the power value calculated by the power calculation section. Thereby, the fluctuation of the DC voltage can be suppressed.

[0005] Further, for example, Patent Document 2 discloses that in the regenerative operation mode, a reference drive signal with a set on-operation time is set so that the switching element of the converter turns on in a 120° interval with a high voltage in each phase of the power supply voltage. A DC current is calculated based on the three-phase alternating current detected by the current detection means, an off-operation time corresponding to the magnitude of the DC current is set, and an on-corrected drive signal is generated by adjusting the on-operation time of the reference drive signal to be shortened by the off-operation time. The on-corrected drive signal ensures an off-operation time that delays the on-timing at the front end of the on-operation time of the reference drive signal and an off-operation time that advances the off-timing at the rear end of the on-operation time of the reference drive signal, and corrects it so that twice the off-operation time can be ensured at the center of the reference drive signal. Thereby, fluctuations in the DC voltage can be suppressed.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] The rectifier disclosed in Patent Document 1 calculates the power flowing between a three-phase AC power source and a DC section. However, even if the power has the same value, when the power supply voltage is low, the current flowing from the DC section to the three-phase AC power source increases, and when the power supply voltage is high, the current flowing from the DC section to the three-phase AC power source decreases. On the other hand, the regenerative current flowing into the three-phase AC power source increases when the on-time of the switching element is long and decreases when the on-time is short. For this reason, if the on-time length of the switching element is changed based on the calculated power, when the power supply voltage is low, the on-time is insufficient and the current regenerated into the three-phase AC power source is small, resulting in a high DC voltage. When the power supply voltage is high, the on-time is too long and the current regenerated into the three-phase AC power source is large, resulting in a low DC voltage.

[0008] Also, the three-phase converter device disclosed in Patent Document 2 controls by setting the off-operation time according to the magnitude of the calculated DC current instead of the power. Therefore, even if the power supply voltage fluctuates, there is no overshoot or undershoot in the compensation amount. However, the DC current is a value calculated by an operation using the square root of the sum of the squares of the phase currents as the amplitude of the DC current of the three-phase AC current, and is not based on the current flowing through the DC section. Therefore, for example, when a current flows between the phases of the power supply, the DC current calculated based on the three-phase AC current may be larger than the current flowing through the DC section, and there is a problem that appropriate compensation cannot be performed. In addition, not only is an off-operation time provided to delay the on-timing at the front end of the on-operation time of the reference drive signal, but also an off-operation time to advance the off-timing at the rear end of the on-operation time of the reference drive signal, and a double off-operation time is ensured in the center of the reference drive signal. Therefore, compared with the normal 120° conduction, the number of switching times per power supply cycle increases, and there is a problem that the loss of the semiconductor switching element increases.

[0009] Furthermore, in the rectifier disclosed in Patent Document 1 and the three-phase converter device disclosed in Patent Document 2, when shifting from the power running state to the regeneration state, the length of the on-time is increased from a short state to a long state according to the power and direct current. However, when the motor is rapidly decelerated from high speed, the regenerative power from the motor becomes maximum at the start of deceleration and decreases as the speed decreases. For this reason, when the on-time is short when the power and direct current immediately after the start of regeneration are small, there is a problem that the large and rapid regenerative power from the motor cannot be regenerated to the power supply and the direct current voltage becomes high.

[0010] Therefore, an object of the present invention is to provide a motor control device with a power regeneration function that suppresses an increase in the direct current voltage against a large and rapid regenerative power from a motor with little switching loss without being affected by the power supply voltage in a 120° conduction type power regeneration converter, and suppresses fluctuations in the direct current voltage by repeating on / off of the regeneration operation against a small regenerative power from the motor.

Means for Solving the Problems

[0011] A motor control device according to one aspect of the present invention is a motor control device with a power regeneration function, a converter circuit that converts alternating current power from a polyphase power supply into direct current power and converts the direct current power into the alternating current power, an inverter circuit that converts the direct current power into the alternating current power for driving the motor, a converter control unit that controls the switching of the converter circuit to regenerate power from the motor to the polyphase power supply when it is detected that the direct current voltage of the direct current power is equal to or higher than a regeneration operation reference voltage that is higher than the voltage peak value of the alternating current power from the polyphase power supply by a first predetermined value, and is provided with The converter control unit has a voltage rise detection unit, a timing compensator, and has When the DC voltage rise detector detects that the DC voltage of the DC power is equal to or higher than a second predetermined value than the regeneration operation reference voltage, it outputs a voltage rise signal, and the timing compensator generates a voltage reference type timing signal for the converter circuit based on the voltage rise signal.

Advantages of the Invention

[0012] In a power supply regeneration converter with a 120° power supply method, it is possible to provide a motor control device with a power supply regeneration function that can prevent the DC voltage from rising against a large and sudden regeneration power from the motor with little switching loss without being affected by the power supply voltage, and can suppress the fluctuation of the DC voltage by repeating the on / off of the regeneration operation against a small regeneration power from the motor.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. For components having the same reference numerals as those already described in the description of the embodiments, the description thereof will be omitted for the sake of convenience of explanation. [First Embodiment]

[0015] FIG. 1 is a block diagram of a motor control device 1 with a power regeneration function according to a first embodiment of the present invention. As shown in FIG. 1, the motor control device 1 has a power regeneration function and includes a converter circuit 2, a smoothing capacitor 3, an inverter circuit 4, a current detection unit 5, an AC reactor ACL, and a converter control unit 10. An AC power supply 100 is connected to the input side of the motor control device 1, and a motor M is connected to the output side. The AC power supply 100 is a three-phase AC power supply, but it may be a multi-phase AC power supply and is not limited to three phases.

[0016] The converter circuit 2 is a three-phase (R-phase, S-phase, T-phase) full-bridge circuit and is composed of six semiconductor switching elements. The semiconductor switching element is composed of, for example, an IGBT and a freewheeling diode connected in anti-parallel. During the power running operation of the motor M, the converter circuit 2 converts the three-phase AC input from the AC power supply 100 into DC. Also, during the regeneration operation, the AC power generated by the motor M is converted into DC by the inverter circuit 4, and the converter circuit 2 converts the converted DC into three-phase AC.

[0017] The smoothing capacitor 3 is, for example, an electrolytic capacitor and smoothes the DC output from the converter circuit 2.

[0018] The inverter circuit 4 is a three-phase (u-phase, v-phase, w-phase) full-bridge circuit and is composed of six semiconductor switching elements. The semiconductor switching element is composed of, for example, an IGBT and a freewheeling diode connected in antiparallel. During the power running operation of the motor M, the inverter circuit 4 converts the direct current from the smoothing capacitor 3 or the direct current output by the converter circuit 2 into three-phase alternating current for motor drive and supplies it to the motor M. During the regenerative operation, the inverter circuit 4 converts the alternating current power generated by the motor M into direct current power.

[0019] The current detection unit 5 detects the alternating current flowing between the AC power supply 100 and the converter circuit 2.

[0020] During the regenerative operation, the motor control device 1 energizes the semiconductor switching elements of the converter circuit 2 by the gate control signal from the converter control unit 10 in the 120° section with the higher voltage in each phase of the power supply voltage and regenerates the power to the AC power supply 100.

[0021] The converter control unit 10 is composed of a timing signal generation unit 20, a regenerative operation determination unit 50, and a gate controller 11. The timing signal generation unit 20 includes a DC current estimation unit 30, a voltage rise detection unit 40, and a timing compensator 21. The DC current estimation unit 30 includes a phase detector 31, a current selection signal generation unit 32, a selector 33, and a filter 34. The voltage rise detection unit 40 includes a crest value detector 41 and a voltage rise detector 42. The regenerative operation determination unit 50 includes a regenerative start detector 51 and a regenerative stop detector 52.

[0022] The phase detector 31 detects the phase of the 120° section where the voltage in each phase of the power supply voltage is high, and outputs a phase signal. The current selection signal generation unit 32 generates an AC current selection signal for performing current selection based on the phase signal. The AC current selection signal is generated so as to select the power supply current of the phase in which the voltage is increasing among the two phases through which the current is flowing. Here, the reason for selecting the power supply current of the phase in which the voltage is increasing is that when control is performed so that the gate timing is advanced from the voltage phase of 120° conduction during the regeneration operation, the current in the voltage rising portion becomes larger than the current in the voltage falling portion.

[0023] Here, the process of selecting the AC current will be described in detail with reference to FIG. 2. FIG. 2 is a diagram showing the power supply current, the phase signal, the current selection signal, and the AC current selected based on the current selection signal in the first embodiment of the present invention. For example, in the first half 60° section of the 120° section where the voltage of the R phase indicated by reference numeral 32a is high, the currents of the R phase and the S phase are flowing, and since the voltage of the R phase is increasing, the R phase is selected. Also, in the latter half 60° section of the 120° section where the voltage of the R phase indicated by reference numeral 32b is high, the currents of the R phase and the T phase are flowing, and since the voltage of the T phase is increasing in the negative direction, the current of the T phase is selected after inverting the sign. Note that the sign is inverted in order to make the sign of the DC current Id of the converter circuit 2 negative during the regeneration operation.

[0024] Returning to the description of FIG. 1, the selector 33 selects the power supply current (AC current) detected by the current detector 5 based on the AC current selection signal from the current selection signal generation unit 32, and outputs the selected power supply current. Here, the selection of the power supply current by the selector 33 is equivalent to AC-DC conversion, and a positive current value is output during the power running operation. The filter 34 removes the ripple component from the power supply current selected and output by the selector 33. The power supply current from which the ripple component has been removed by the filter 34 is output as an estimated value of the DC current Id to the timing compensator 21 and the regeneration stop detector 52.

[0025] In this way, the DC current estimator 30 can accurately estimate the DC current Id of the converter circuit 2 during the regeneration operation by detecting the phase with the higher voltage among the phases of the AC power and selecting the current of one of the phases of the AC power based on the detected phase.

[0026] The peak detector 41 detects the peak value Vp of the power supply voltage and outputs it to the voltage rise detector 42 and the regeneration start detector 51. The regeneration start detector 51 detects that the DC voltage Vd across the smoothing capacitor 3 is equal to or higher than the regeneration operation reference voltage Vstd, and outputs a regeneration operation start signal to the gate controller 11. Here, the regeneration operation reference voltage Vstd is a value that is higher than the peak value Vp of the power supply voltage detected by the peak detector 41 by a first predetermined value V1, and is a reference value for the converter control unit 10 to determine whether to perform the regeneration operation. The voltage rise detector 42 detects that the DC voltage Vd is equal to or higher than the regeneration operation reference voltage Vstd by a second predetermined value V2, and outputs a voltage rise signal to the timing compensator 21. In this way, even if the regeneration operation start signal is output by the regeneration start detector 51 and the regeneration operation is started, when the DC voltage Vd is still high, the voltage rise detector 42 is configured to output a voltage rise signal.

[0027] The regeneration stop detector 52 detects that the estimated value of the DC current Id output from the DC current estimator 30 is positive, and outputs a regeneration operation stop signal to the gate controller 11.

[0028] The timing compensator 21 performs gate timing compensation on the phase signal from the phase detector 31 based on the estimated value of the DC current Id from the filter 34 and the voltage rise signal from the voltage rise detector 42. There are two types of timing compensation for the gate timing compensation: voltage reference type timing compensation based on the voltage rise signal and current reference type timing compensation based on the estimated value of the DC current Id. The timing compensator 21 performs voltage reference type timing compensation when a voltage rise signal is input from the voltage rise detector 42, and performs current reference type timing compensation when no voltage rise signal is input from the voltage rise detector 42.

[0029] The current reference type gate timing compensation will be described with reference to FIGS. 3 to 5. FIG. 3 is a diagram showing the waveform of the gate timing signal when the estimated value of the DC current Id is large in the negative direction. FIG. 4 is a diagram showing the waveform of the gate timing signal when the estimated value of the DC current Id is small in the negative direction. FIG. 5 is a diagram showing the relationship between the estimated value of the DC current Id and the adjustment phase φ.

[0030] In the current reference type gate timing compensation, when the estimated value of the DC current Id is large in the negative direction, as shown in the lower part of FIG. 3, the timing compensator 21 advances the gate-on timing by the adjustment phase φ. In this state, the regeneration operation is performed in the entire section. Note that the gate-off timing is advanced by a certain amount with respect to the phase signal in the 120° section where the voltage of each phase is high. When the estimated value of the DC current Id is large, as shown in FIG. 2, within the energization section of the selected alternating current (regeneration current) (for example, the section indicated by reference numeral 32a), the waveform of the first mountain shape is adjusted to be higher than the waveform of the second mountain shape among the two mountain-shaped waveforms.

[0031] Also, in the current reference type gate timing compensation, when the estimated value of the DC current Id is small in the negative direction, as shown in the lower part of FIG. 4, the timing compensator 21 delays the gate-on timing by the adjustment phase φ. In this state, the section Tr in which the regeneration operation is performed becomes narrower.

[0032] Next, with reference to FIG. 5, the relationship between the estimated value of the direct current Id and the adjustment phase φ will be specifically described. As shown in FIG. 5, in the current reference type gate timing compensation, when the estimated value of the direct current Id is 0, by setting the adjustment phase φ to -φ0, as shown in FIG. 4, for the phase signals in the 120° intervals where the voltages in each phase of the power supply voltage are high, the gate-on timing is delayed to shorten the section where the regeneration operation is performed. Also, when the estimated value of the direct current Id is between 0 and -I1, the adjustment phase φ is linearly increased from -φ0 to 0 to gradually increase the section where the regeneration operation is performed. When the estimated value of the direct current Id is between -I1 and -I2, the adjustment phase φ is linearly increased from 0 to φ2, and as shown in FIG. 3, for the above phase signal, the gate-on timing is advanced to further increase the section where the regeneration operation is performed so that the regeneration operation is performed in the entire section. When the estimated value of the direct current Id is between -I2 and -I3, the adjustment phase φ is linearly increased from φ2 to φ3, and the gate-on timing is further advanced for the above phase signal so that the current in the voltage rising section of the power supply voltage is larger than the current in the voltage dropping section. When the estimated value of the direct current Id is larger in the negative direction than -I3, the adjustment phase φ is fixed at φ3. Here, the reason for fixing the adjustment phase φ at φ3 is to prevent overcompensation for a sudden change in the regenerative power.

[0033] Next, the voltage reference type gate timing compensation will be described. In the voltage reference type gate timing compensation, regardless of the estimated value of the direct current Id, for a certain period after the voltage rising signal is input to the timing compensator 21, the adjustment phase φ is fixed at φ3 to expand the section Tr where the regeneration operation is performed. That is, in the voltage reference type gate timing compensation, instead of gradually increasing the adjustment phase φ as in the current reference type gate timing compensation, it is fixed at φ3 from the beginning. Thereby, by regenerating the sudden regenerative power from the motor M to the AC power supply 100, it is possible to prevent the DC voltage Vd from increasing.

[0034] Here, the variation of the DC voltage Vd in the present embodiment will be described with reference to FIGS. 6 and 7. FIG. 6 is a diagram showing waveforms illustrating the regenerative operation when the motor is decelerated from high speed in a state where the voltage rise detector 42 is not operating, as a comparative example. FIG. 7 is a diagram showing waveforms illustrating the regenerative operation when the motor M is decelerated from high speed in a state where the voltage rise detector 42 is operating in the embodiment of the present invention.

[0035] In the comparative example shown in FIG. 6, first, when the motor M is decelerated from high speed, the DC voltage Vd applied to the smoothing capacitor 3 increases. Next, at time t0, the regeneration start detector 51 detects that the DC voltage Vd is equal to or higher than the regenerative operation reference voltage Vstd, and a regenerative operation start signal is output to the gate controller 11. Accordingly, the gate controller 11 energizes the semiconductor switching element of the converter circuit 2 to start the regenerative operation. Thereafter, the DC voltage Vd further increases and becomes equal to or higher than a second predetermined value V2 from the regenerative operation reference voltage Vstd. However, since the voltage rise detector 42 is not operating, a voltage rise signal is not input from the voltage rise detector 42 to the timing compensator 21, and current reference type timing compensation is performed. Thereafter, as the estimated value of the DC current Id gradually decreases, the adjustment phase φ is gradually increased at time t 1、 t2, advancing the gate-on timing with respect to the phase signal, and gradually increasing the section in which the regenerative operation is performed. Here, since the on-time of the semiconductor switching element of the converter circuit 2 is short at the start of the regenerative operation, a large and rapid regenerative power from the motor M cannot be regenerated to the power supply, and the DC voltage Vd has risen to a maximum of 317V. Thereafter, the estimated value of the DC current Id gradually increases, and at time t3, the regeneration stop detector 52 detects that the estimated value of the DC current Id is positive, and a regenerative operation stop signal is output to the gate controller 11. Accordingly, the gate controller 11 stops the regenerative operation.

[0036] On the other hand, in the embodiment of the present invention shown in FIG. 7, first, by decelerating the motor M from high speed, the DC voltage Vd applied to the smoothing capacitor 3 increases. Next, at time t0, it is detected by the regeneration start detector 51 that the DC voltage Vd is equal to or higher than the regeneration operation reference voltage Vstd, and a regeneration operation start signal is output to the gate controller 11. Accordingly, the gate controller 11 energizes the semiconductor switching element of the converter circuit 2 to start the regeneration operation. Thereafter, the DC voltage Vd further increases and becomes equal to or higher than the second predetermined value V2 from the peak value Vp of the power supply voltage at time t1', and the voltage increase detector 42 outputs a voltage increase signal. The timing compensator 21 fixes the adjustment phase φ to φ3 for a certain period (20 ms in the example shown in FIG. 7) after the voltage increase signal is input from the voltage increase detector 42, and expands the section Tr in which the regeneration operation is performed. As a result, by regenerating the sudden regeneration power from the motor M to the AC power supply 100, the increase in the DC voltage Vd is suppressed to 304 V or less. Thereafter, the estimated value of the DC current Id gradually increases, and at time t3, it is detected by the regeneration stop detector 52 that the estimated value of the DC current Id is positive, and a regeneration operation stop signal is output to the gate controller 11. Accordingly, the gate controller 11 stops the regeneration operation.

[0037] As described above, in the embodiment of the present invention, a voltage reference type timing signal for the converter circuit is generated based on the voltage increase signal. Thereby, without being affected by the power supply voltage, it is possible to suppress the increase in the DC voltage with respect to the sudden large regeneration power from the motor M with less switching loss.

[0038] Further, in the embodiment of the present invention, the timing compensator 21 performs voltage reference type gate timing compensation, and after regenerating the sudden regeneration power from the motor M to the AC power supply 100, performs current reference type gate timing compensation. Thereby, after suppressing the increase in the DC voltage with respect to the sudden and large regeneration power from the motor M, it is possible to suppress the fluctuation of the DC voltage Vd by generating a timing signal referring to the estimated DC current Id.

[0039] Further, in the embodiment of the present invention, in FIG. 7, when the DC voltage Vd does not become equal to or higher than a second predetermined value V2 than the peak value Vp of the power supply voltage, the timing compensator 21 performs current reference type gate timing compensation. Thereby, it is possible to suppress the DC voltage Vd from fluctuating due to the on / off of the regeneration operation being repeated for small regeneration power from the motor M.

[0040] As described above, the embodiments of the present invention have been described. Needless to say, the technical scope of the present invention should not be construed in a limited manner by the description of the present embodiment. This embodiment is merely an example, and it is understood by those skilled in the art that various modifications of the embodiments are possible within the scope of the invention described in the claims. The technical scope of the present invention should be determined based on the scope of the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0041] 1: Motor control device 2: Converter circuit 3: Smoothing capacitor 4: Inverter circuit 5: Current detection unit 10: Converter control unit 11: Gate controller 20: Timing signal generation unit 21: Timing compensator 30: DC current estimation unit 31: Phase detector 32: Current selection signal generation unit 33: Selector 34: Filter 40: Voltage rise detection unit 41: Peak value detector 42: Voltage rise detection unit 50: Regeneration operation determination unit 51: Regeneration start detector 52: Regeneration stop detector 100: AC power supply M: Motor φ: Adjustment phase

Claims

1. A motor control device with a power regeneration function, a converter circuit that converts AC power from a polyphase power supply into DC power and converts the DC power back into the AC power, an inverter circuit that converts the DC power into the AC power for driving the motor, a converter control unit that controls the switching of the converter circuit to regenerate power from the motor to the polyphase power supply when it is detected that the DC voltage of the DC power is equal to or higher than a regeneration operation reference voltage that is higher than the voltage peak value of the AC power from the polyphase power supply by a first predetermined value, comprising, the converter control unit, a voltage rise detector, a timing compensator, having, wherein the voltage rise detector outputs a voltage rise signal when it is detected that the DC voltage of the DC power is equal to or higher than a second predetermined value than the regeneration operation reference voltage, and the timing compensator generates a voltage reference type timing signal for the converter circuit based on the voltage rise signal. A motor control device characterized by this.

2. The converter control unit, has a DC current estimation unit that estimates the DC current of the DC power, the timing compensator, after generating the voltage reference type timing signal, generates a current reference type timing signal for the converter circuit based on the DC current estimated by the DC current estimation unit. The motor control device according to claim 1, characterized by this.

3. The converter control unit, when it is detected that the DC voltage is less than the second predetermined value than the regeneration operation reference voltage, generates the current reference type timing signal based on the DC current estimated by the DC current estimation unit. The motor control device according to claim 2, characterized by this.

4. The DC current estimation unit, detects the phase with the highest voltage among each phase of the AC power, and based on the detected phase, selects the current of any phase of the AC power to estimate the DC current. The motor control device according to claim 2, characterized by this.

5. The converter control unit further has a regeneration operation determination unit including a regeneration start detector and a regeneration stop detector, the regeneration start detector outputs a regeneration operation start signal when it is detected that the DC voltage of the DC power is equal to or higher than the regeneration operation reference voltage, the regeneration stop detector outputs a regeneration operation stop signal when it is detected that the DC current of the DC power is a positive value, The motor control device according to claim 1, wherein the converter control unit controls the switching of the converter circuit based on the regeneration operation start signal and the regeneration operation stop signal.

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