JP2022076768A - Inverter controller - Google Patents

Abstract

To provide an inverter controller capable of demagnetizing a permanent magnet by a simple method.SOLUTION: An inverter controller 50 comprises: a necessity determination unit that determines whether or not demagnetization of a permanent magnet 34 constituting a rotary electric machine 30 is necessary; and a demagnetization execution unit that performs short circuit control of causing a reflux current to flow to a closed circuit including a coil 31 constituting a turned-on arm switch and the rotary electric machine 30 by turning on one of upper and lower arm switches SWp and SWn in all phases and turning off the other arm switch in all phases of an inverter 40 when it is determined that demagnetization is necessary, and performs cut-off control of realizing a state where a reflux current does not flow after performing the short circuit control.SELECTED DRAWING: Figure 2

Description

The present invention relates to an inverter control device.

Conventionally, as described in Patent Document 1, a system including a rotary electric machine and an inverter is known. The rotary electric machine includes a rotor having a permanent magnet and a stator having a plurality of phases of coils, and serves as a running power source for the vehicle. The inverter is provided with an upper and lower arm switch for each phase, and electrically connects the power storage unit and the coil. The upper and lower arm switches are switches in which external diodes are connected in antiparallel, or switches in which parasitic diodes are built-in. The inverter control device applied to this system controls the switching of the upper and lower arm switches.

Japanese Unexamined Patent Publication No. 2017-11260

When the drive wheels of the vehicle rotate with the movement of the vehicle, the rotor rotates, and the magnetic flux of the permanent magnet generates a counter electromotive voltage in the coil. As the rotation speed of the rotor increases, the counter electromotive voltage increases. As a result, for example, even when all the upper and lower arm switches are turned off, a current flows from the coil to the storage unit via the diode, and the voltage of the storage unit may become excessively high. In this case, a problem such as a failure of the power storage unit may occur. Further, for example, by switching the system main relay (SMR) to OFF, it is possible to avoid charging the power storage unit. However, in this case, the counter electromotive voltage is directly applied to the inverter and other devices connected in parallel with the inverter. In this case, if the counter electromotive voltage exceeds the withstand voltage of the components, the components may fail.

This problem can occur, for example, when the own vehicle is towed by another vehicle. As the traveling speed of the towed vehicle increases, the rotation speed of the rotor also increases and the counter electromotive voltage increases. As a result, the voltage of the power storage unit may become excessively high.

Patent Document 1 describes a method of irreversibly demagnetizing a permanent magnet by heating a permanent magnet by alternately switching between positive and negative of a d-axis current and then flowing a d-axis current in a negative direction. This reduces the counter electromotive voltage. However, this method requires complicated control of the d-axis current.

It should be noted that the above-mentioned problems may occur in the same manner as long as the moving body is not limited to the vehicle but is equipped with a rotating electric machine as a moving power source.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an inverter control device capable of demagnetizing a permanent magnet by a simple method.

The present invention includes a power storage unit and
A rotary electric machine having a rotor having a permanent magnet and a stator having a multi-phase coil and serving as a moving power source for a moving body,
An inverter having upper and lower arm switches to which diodes are connected in antiparallel connection and electrically connecting the power storage unit and the coil.
In an inverter controller applied to a system equipped with
A necessity determination unit for determining whether or not demagnetization of the permanent magnet is necessary, and
When it is determined by the necessity determination unit that demagnetization is necessary, one of the upper and lower arm switches is turned on in all phases and the other arm switch is turned off in all phases. With a cutoff control unit that executes a short-circuit control in which a recirculation current is passed through the closed circuit including the arm switch and the coil that have been turned ON, and after the execution of the short-circuit control, the cutoff control is performed so that the recirculation current does not flow. , Equipped with.

In the present invention, when the necessity determination unit determines that demagnetization of the permanent magnet is necessary, the shunt control unit executes short-circuit control. As a result, the reflux current flows through the closed circuit including the arm switch and the coil that are turned on.

Here, when the short-circuit control is executed, the operating point specified by the d and q-axis current values in the dq coordinate system finally has the q-axis current value of 0 and the d-axis current value. Converges to the final arrival position where is a negative predetermined value. In this case, the operating point does not linearly move from the operating point at the start of the short-circuit control to the final arrival position, but draws a swirling trajectory around the final arrival position and heads toward the final arrival position. In the process toward the final arrival position, the d-axis current increases intermittently in the negative direction. By utilizing this d-axis current, the permanent magnet can be demagnetized.

However, if the short circuit control continues to be executed, the reflux current will continue to flow. In this case, the d-axis current continues to flow, and the permanent magnet may be demagnetized too much. In addition, the current continues to flow in the arm switch that is turned on by the short-circuit control, and the arm switch in which the current continues to flow may fail.

Therefore, in the present invention, after the short-circuit control in which the recirculation current for demagnetization is passed is executed, the cutoff control in which the recirculation current does not flow is executed. Therefore, it is possible to suppress the occurrence of a situation in which the permanent magnet is demagnetized too much or the arm switch to be turned on fails.

According to the present invention described above, the permanent magnet can be demagnetized while suppressing the occurrence of failure of the inverter or the like by simple control such as short circuit control and cutoff control.

The overall block diagram of the in-vehicle control system which concerns on 1st Embodiment. The figure which shows the inverter, the rotary electric machine, and the peripheral structure thereof. Functional block diagram of the inverter controller. The figure which shows the transition of d, q-axis current values when three-phase short-circuit control is continued. The figure which shows the necessity determination part, the demagnetization execution part, and the peripheral structure thereof. A flowchart showing the procedure of demagnetization control. The figure which shows the transition of the d, q-axis current values when demagnetization control is executed. A time chart showing changes in the duration of three-phase short-circuit control and shutdown control. The figure which shows the relationship between the magnet temperature and the duration of three-phase short circuit control which concerns on 2nd Embodiment. The flowchart which shows the procedure of demagnetization control which concerns on 3rd Embodiment. The flowchart which shows the procedure of demagnetization control which concerns on 4th Embodiment. The flowchart which shows the procedure of demagnetization control which concerns on 5th Embodiment. The flowchart which shows the procedure of demagnetization control which concerns on 6th Embodiment. The figure which shows the inverter, the rotary electric machine and the peripheral structure thereof which concerns on other embodiment.

<First Embodiment>
Hereinafter, the first embodiment in which the control device according to the present invention is embodied will be described with reference to the drawings. The control device according to the present embodiment constitutes a control system together with a rotary electric machine as a traveling power source, and the control system is mounted on a vehicle.

As shown in FIG. 1, the vehicle 10 includes left and right front wheels 11a, left and right rear wheels 11b, and a high-voltage battery 20. The high voltage battery 20 is, for example, a lithium ion storage battery or a nickel hydrogen storage battery. In the following, the front wheels 11a and the rear wheels 11b may be simply referred to as drive wheels 11.

The control system mounted on the vehicle 10 includes an inverter 40 that electrically connects the rotary electric machine 30, the high-pressure battery 20, and the rotary electric machine 30, an inverter control device 50 that controls the inverter 40, and a host control device 80 (FIG. 2) and. In the present embodiment, the rotary electric machine 30 is an on-board motor. Further, the control system includes two sets of a rotary electric machine 30 and an inverter 40. Of the two sets of the rotary electric machine 30 and the inverter 40, one set constitutes a power system for applying a driving force to the front wheels 11a, and the other set constitutes a power system for applying a driving force to the rear wheels 11b. Configure the system. In the present embodiment, the rotary electric machine 30 is a synchronous machine, and more specifically, a permanent magnet synchronous machine. In the present embodiment, the configurations of the two sets of the rotary electric machine 30 and the inverter 40 are basically the same. Therefore, in the following, one of the two sets will be mainly described.

FIG. 2 is a diagram showing an electrical configuration of the rotary electric machine 30 and the inverter 40.

The rotary electric machine 30 includes a stator 32 and a rotor 33. The rotating shaft of the rotor 33 is connected to the drive wheels 11 via a transmission, a shaft 12, and the like (not shown). The stator 32 is provided with a three-phase coil 31. The rotor 33 is provided with a permanent magnet 34.

The inverter 40 includes a series connection body of the upper arm switch SWp and the lower arm switch SWn for three phases. In the present embodiment, each switch SWp, SWn is a voltage-controlled semiconductor switching element, and more specifically, an IGBT. The upper and lower arm diodes Dp and Dn, which are freewheel diodes, are connected in antiparallel to the upper and lower arm switches SWp and SWp.

In each phase, the emitter, which is the low potential side terminal of the upper arm switch SWp, and the collector, which is the high potential side terminal of the lower arm switch SWn, are connected to the first end of the coil 31 via a conductive member Lm such as a bus bar. Is connected. The second end of the coil 31 of each phase is connected at the neutral point. That is, the coils 31 of each phase are star-connected. The coils 31 of each phase are arranged so as to be offset by 120 ° from each other by the electric angle.

The first end of the first cutoff switch SWRp is connected to the collector of the upper arm switch SWp of each phase via the high potential side path Lp. The first end of the second cutoff switch SWRn is connected to the emitter of the lower arm switch SWn of each phase via the low potential side path Ln. The positive electrode terminal of the high voltage battery 20 is connected to the second end of the first cutoff switch SWRp, and the negative electrode terminal of the high voltage battery 20 is connected to the second end of the second cutoff switch SWRn. In the present embodiment, each cutoff switch SWRp, SWRn is a relay (specifically, for example, a system main relay). Each cutoff switch SWRp, SWRn is operated by the inverter control device 50 or the host control device 80.

The control system includes a smoothing capacitor 41 and an in-vehicle electric device 42. The smoothing capacitor 41 connects the high potential side path Lp and the low potential side path Ln. The electric device 42 is connected to the high potential side path Lp and the low potential side path Ln. The electrical device 42 includes, for example, at least one of an electric compressor and a DCDC converter. The electric compressor constitutes an air conditioner in the vehicle interior and is driven by being supplied with power from the high-pressure battery 20 in order to circulate the refrigerant in the in-vehicle refrigeration cycle. The DCDC converter steps down the output voltage of the high-voltage battery 20 and supplies it to the vehicle-mounted low-voltage load. Low voltage loads include low voltage batteries (not shown). The low voltage battery is a secondary battery whose output voltage (for example, rated voltage) is lower than the output voltage (rated voltage) of the high voltage battery 20, and is, for example, a lead storage battery.

When the cutoff switches SMRp and SMRn are turned on, the high-voltage battery 20 and the smoothing capacitor 41 serve as storage units for the inverter 40 and the electric device 42. On the other hand, when the cutoff switches SMRp and SMRn are turned off, the smoothing capacitor 41 of the high-voltage battery 20 and the smoothing capacitor 41 serves as a storage unit for the inverter 40 and the electric device 42.

The control system includes a phase current detection unit 43, an angle detection unit 44, and a voltage detection unit 45. The phase current detection unit 43 detects at least two phases of the currents of each phase flowing through the rotary electric machine 30. The angle detection unit 44 detects the electric angle of the rotor 33, and is, for example, a resolver. The voltage detection unit 45 detects the voltage between the terminals of the smoothing capacitor 41.

The control system includes a first temperature detection unit 46 and a second temperature detection unit 47. The first temperature detection unit 46 detects the temperatures of the diodes Dp and Dn and the switches SWp and SWn constituting the inverter 40. The second temperature detection unit 47 detects the temperature of the permanent magnet 34.

The control system includes a direct current detection unit 48. The DC current detection unit 48 detects the current flowing in the high potential side path Lp. The detected values of the detection units 43 to 48 are input to the inverter control device 50.

The inverter control device 50 is an ECU (electronic control unit) having a CPU, RAM, ROM, and the like. The inverter control device 50 performs power running drive control. The power running control is a switching control of the upper and lower arm switches SWp and SWn for converting the DC power output from the high voltage battery 20 into AC power and supplying it to the coil 31. When this control is performed, the rotary electric machine 30 functions as an electric machine and generates a power running torque (> 0). Further, the inverter control device 50 performs regenerative drive control. The regenerative drive control is a switching control of the upper and lower arm switches SWp and SWn for converting the AC power generated by the rotary electric machine 30 into DC power and supplying it to the high-voltage battery 20. When this control is performed, the rotary electric machine 30 functions as a generator and generates regenerative torque (<0).

FIG. 3 is a block diagram of a process executed by the inverter control device 50. In the inverter control device 50, the torque command unit 51 calculates the torque command value Trq * by receiving a command from the host control device 80. The current command unit 52 calculates the d-axis current command value Id * and the q-axis current command value Iq * based on the calculated torque command value Trq *.

The dq conversion unit 53 has a d-axis current value Idr and a q-axis current value Iqr in the dq coordinate system based on the phase current detected by the phase current detection unit 43 and the electric angle θe detected by the angle detection unit 44. Is calculated.

The deviation calculation unit 54 is the difference between the d-axis current deviation ΔId, which is the difference between the d-axis current command value Id * and the d-axis current value Idr, and the q-axis current command value Iq *, and the q-axis current value Iqr. The shaft current deviation ΔIq is calculated.

The feedback control unit 55 calculates the d-axis voltage command value Vd * as an operation amount for feedback-controlling the d-axis current deviation ΔId to 0, and q as an operation amount for feedback-controlling the q-axis current deviation ΔIq to 0. The shaft voltage command value Vq * is calculated. The feedback control is, for example, proportional integral control.

The modulator 56 is U, V based on the d, q-axis voltage command values Vd *, Vq *, the electric angle θe, and the power supply voltage Vb, which is the voltage between the terminals of the smoothing capacitor 41 detected by the voltage detection unit 45. , W phase voltage command values Vu *, Vv *, Vw * are calculated. More specifically, to explain by taking the U phase as an example, the modulator 56 is based on a magnitude comparison between a signal obtained by standardizing the U phase voltage command value Vu * with the power supply voltage Vb and a carrier signal such as a triangular wave signal. A U-phase drive signal to be supplied to the gates of the upper and lower arm switches SWp and SWn of the phase is generated. Similarly, the modulator 56 supplies a V-phase drive signal supplied to the gates of the V-phase upper and lower arm switches SWp and SWn, and a W-phase drive signal supplied to the gates of the W-phase upper and lower arm switches SWp and SWn. Generate a signal. Each drive signal is an OFF command instructing the switch to be turned off or an ON command instructing the switch to be turned on. By supplying each drive signal to the gates of the upper and lower arm switches SWp and SWn, the upper and lower arm switches SWp and SWn of each phase are switched and controlled.

The inverter control device 50 includes a necessity determination unit 57 and a demagnetization execution unit 58. Hereinafter, the reason why the necessity determination unit 57 and the demagnetization execution unit 58 are provided will be described.

The vehicle 10 may not be able to run on its own due to, for example, a breakdown. In this case, the vehicle 10 is a other vehicle (for example, a tow truck) with both the front wheels 11a and the rear wheels 11b in contact with the road surface, or with one of the front wheels 11a and the rear wheels 11b being lifted and the other in contact with the road surface. ) May be towed. In this case, the drive wheels 11 of the vehicle 10 rotate as the other vehicle travels. Along with the rotation, the rotor 33 rotates, and the magnetic flux of the permanent magnet 34 generates a counter electromotive voltage in the three-phase coil 31.

When the vehicle 10 is towed, normally, the cutoff switches SWRp and SMRn are turned off, and in the inverter 40, shutdown control is executed in which the upper and lower arm switches SWp and SWn of all phases are turned off. In this case, when the counter electromotive voltage exceeds the voltage between the terminals of the smoothing capacitor 41, a current flows from each coil 31 to the smoothing capacitor 41 via the inverter 40, and the voltage between the terminals of the smoothing capacitor 41 becomes high. As a result, if the counter electromotive voltage exceeds the withstand voltage of at least one of the diodes Dp, Dn, the upper and lower arm switches SWp, SWn, the smoothing capacitor 41, and the electric device 42, the device may fail.

In particular, when the traveling speed of another vehicle is high or the permanent magnet 34 has a high magnetic flux density in order to increase the torque of the rotary electric machine 30, the counter electromotive voltage tends to be high, and the above-mentioned failure occurs. Is likely to occur. As a rotary electric machine with high torque, specifically, as described in Japanese Patent Application Laid-Open No. 2019-106866, the intrinsic coercive force is 400 [kA / m] or more, and the intrinsic coercive force is 400 [kA / m] or more. There is a slotless structure having a permanent magnet having a residual magnetic flux density of 1.0 T or more.

Further, even when the vehicle 10 is not towed, the same problem may occur when the power running drive of one of the two rotary electric machines 30 cannot be carried out and the running of the vehicle 10 is continued by the power running drive of the other. ..

In order to deal with such a problem, the demagnetization execution unit 58 performs demagnetization control to reduce the countercurrent voltage by irreversibly demagnetizing the permanent magnet 34 as needed. In the following, irreversible demagnetization may be simply referred to as demagnetization. The demagnetization control is a control including a three-phase short circuit control and a shutdown control corresponding to a cutoff control. The three-phase short-circuit control of the present embodiment is a control in which the lower arm switch SWn of all phases is turned on and the upper arm switch SWp of all phases is turned off. The three-phase short circuit control is also called ASC (Active Short Circuit) control.

In the demagnetization control, the shutdown control is executed after the execution of the three-phase short circuit control. The reason for this will be described below.

FIG. 4 is a diagram of the dq coordinate system showing the transition of the d and q-axis current values Id and Iq when the three-phase short-circuit control is continued. In the following, the position specified by the d, q-axis current values Id, Iq in the dq coordinate system of the current value will be referred to as an operating point OP. Further, in the present embodiment, the sign of the d-axis current Id when the field is strengthened is positive, and the sign of the d-axis current Id when the field is weakened is negative. Further, the sign of the q-axis current Iq when the force running torque is generated in the first rotation direction of the rotor 33 by the force running control is positive, and the regenerative drive control regenerates in the second rotation direction opposite to the first rotation direction. The sign of the q-axis current Iq when generating torque is negative.

When the three-phase short-circuit control is executed, a reflux current flows through the inverter 40 and the coil 31. In this case, as shown in FIG. 4, the operating point OP finally reaches the final arrival position M where the q-axis current value Iq is 0 and the d-axis current value Id becomes a negative predetermined value. Converge. This predetermined value is, for example, a value when the magnetic flux of the permanent magnet 34 and the magnetic flux generated in the coil 31 by the d-axis current value Id and in the direction of canceling the magnet magnetic flux are equal to each other.

The operating point OP does not go straight from the start position Ps where the three-phase short-circuit control is started to the final arrival position M, but draws a trajectory that swirls clockwise around the final arrival position M. Head to the arrival position M. In the example shown in FIG. 4, the locus of the operating point OP from the start position Ps to the final arrival position M is sandwiched between the second and third quadrants and the second and third quadrants in the dq coordinate system of the current value. It exists in the area of the d-axis. The second quadrant is a region where the q-axis current value Iq is a positive value and the d-axis current value Id is a negative value, and the third quadrant is a region where both the d and q-axis current values Id and Iq are negative. This is the area that becomes the value of.

In the process of the operating point OP toward the final arrival position M, the d-axis current increases intermittently in the negative direction. By utilizing this d-axis current, the permanent magnet 34 can be demagnetized. However, if the three-phase short circuit control continues to be executed, the reflux current continues to flow. In this case, the d-axis current will continue to flow, and the permanent magnet 34 may be demagnetized too much, or the current may flow to the lower arm switch SWn that is turned on by the three-phase short-circuit control, causing the lower arm switch SWn to fail. There is.

Therefore, in the present embodiment, the shutdown control is executed after the execution of the three-phase short circuit control. As a result, the reflux current is prevented from flowing.

FIG. 5 is a block diagram showing a necessity determination unit 57, a demagnetization execution unit 58, and their peripheral configurations.

The host control device 80 determines whether or not an abnormality has occurred in the vehicle 10. For example, when it is determined that any of the following conditions (A1) to (A3) is satisfied, the host control device 80 determines that an abnormality has occurred in the vehicle 10.

(A1) Condition that the vehicle 10 collided and the airbag was activated (A2) Condition that the vehicle 10 was towed by another vehicle (A3) Condition that an abnormality occurred in the control system Abnormality of the control system Includes at least one abnormality in each rotary electric machine 30 and each inverter 40, and at least one abnormality in each of the detection units 43 to 48. The abnormality of the inverter 40 includes a short failure or an open failure of the upper and lower arm switches SWp and SWn.

When the host control device 80 determines that an abnormality has occurred in the vehicle 10, the inverter control device 50 is configured so that the drive signal of each phase output from the modulator 56 becomes an OFF command. This configuration can be realized, for example, by instructing the torque command unit 51 to stop the calculation of the torque command value Trq * from the host control device 80.

Further, when the host control device 80 determines that an abnormality has occurred in the vehicle 10, the host control device 80 transmits an abnormality notification signal to the necessity determination unit 57.

When the necessity determination unit 57 receives the abnormality notification signal from the host control device 80, whether or not there is an abnormality in the configurations of the inverter 40 and the inverter control device 50 necessary for executing the three-phase short-circuit control and the shutdown control. Is determined. In the present embodiment, this abnormality includes the following abnormalities (B1) to (B4).

(B1) Abnormality in which the switching state of the lower arm switch SWn cannot be switched (B2) Short-circuit failure of the upper arm switch SWp (B3) Drive signal of each phase for executing three-phase short-circuit control and shutdown control in the inverter control device 50 (B4) Abnormality of the function of generating the above and the function of transmitting the generated drive signal to the gates of the switches SWp and SWn When it is determined that there is no abnormality in the configuration necessary for executing the three-phase short-circuit control and the shutdown control, the abnormality necessity determination unit 57 of at least one of the unit 48, the voltage detection unit 45 and the first temperature detection unit 46) determines that there is no abnormality. It is determined whether or not demagnetization of the permanent magnet 34 is necessary. In the present embodiment, the necessity determination unit 57 determines that demagnetization is necessary when any of the first to third conditions is satisfied, and reduces when any of the first to third conditions is not satisfied. It is determined that magnetism is unnecessary.

Here, the first condition is that the DC current value Ip detected by the DC current detection unit 48 is smaller than the current threshold value Is. In the present embodiment, the sign of the DC current value Ip when flowing through the high potential side path Lp from the high voltage battery 20 side toward the inverter 40 side is positive. Further, the current threshold value Is is set to 0 or a value slightly smaller than 0.

The first condition is a condition for determining whether or not the smoothing capacitor 41 is in a charged state. When the necessity determination unit 57 determines that the DC current value Ip is equal to or greater than the current threshold value Is, it determines that the smoothing capacitor 41 is not in the charged state, and determines that demagnetization is unnecessary. On the other hand, when the necessity determination unit 57 determines that the DC current value Ip is smaller than the current threshold value Is, it determines that the smoothing capacitor 41 is not in the charged state and determines that demagnetization is necessary. When the DC current value Ip is less than 0, the smoothing capacitor 41 is charged by the charging current caused by the counter electromotive voltage, and the voltage between the terminals of the smoothing capacitor 41 rises. As a result, problems such as failure of the smoothing capacitor 41 and the electric device 42 may occur. The first condition is set to deal with this problem.

The second condition is that the power supply voltage Vb is higher than the voltage threshold value Vth. For example, the voltage threshold Vth has the same value as the lowest withstand voltage or slightly higher than the lowest withstand voltage among the withstand voltage of each of the high-voltage battery 20, the smoothing capacitor 41, and the electric device 42 when the cutoff switches SMRp and SMRn are turned on. Set to a low value. Further, for example, the voltage threshold Vth is set to the same value as the lowest withstand voltage or slightly lower than the lowest withstand voltage among the withstand voltage of each of the smoothing capacitor 41 and the electric device 42 when the cutoff switches SMRp and SMRn are turned off. Set.

When the necessity determination unit 57 determines that the power supply voltage Vb is equal to or less than the voltage threshold value Vth, the necessity determination unit 57 determines that demagnetization is unnecessary. On the other hand, when the necessity determination unit 57 determines that the power supply voltage Vb is higher than the voltage threshold value Vth, the necessity determination unit 57 determines that demagnetization is necessary. By setting the second condition, it can be determined that demagnetization is necessary before the power supply voltage Vb exceeds the withstand voltage of at least one of the high voltage battery 20, the smoothing capacitor 41, and the electric device 42.

The third condition is that the element temperature Tdr, which is the temperature detected by the first temperature detection unit 46, is higher than the temperature threshold value Tds. The element temperature Tdr is, for example, the highest temperature (for example, the temperature of the diodes Dp and Dn) among the temperatures of the components to be detected by the first temperature detection unit 46. The third condition is a condition for suppressing the occurrence of a situation in which the components of the inverter 40 are overheated and fail. When the necessity determination unit 57 determines that the element temperature Tdr is equal to or less than the temperature threshold value Tdt, it determines that demagnetization is unnecessary. On the other hand, when the necessity determination unit 57 determines that the element temperature Tdr is higher than the temperature threshold value Tds, it determines that demagnetization is necessary. By demagnetizing, the counter electromotive voltage can be suppressed and the current flowing through the elements constituting the inverter 40 can be reduced.

When the necessity determination unit 57 determines that demagnetization is unnecessary, the logic of the demagnetization command output to the demagnetization execution unit 58 is set to L, and when it is determined that demagnetization is necessary, the demagnetization command is issued. Set the logic to H.

The demagnetization execution unit 58 includes a shutdown determination unit 58a, a NOT circuit 58b, and an AND circuit 58c. A demagnetization command of the necessity determination unit 57 is input to the shutdown determination unit 58a. The shutdown determination unit 58a includes a timer that counts the elapsed time Ltr after the logic of the demagnetization command is switched to H. The shutdown determination unit 58a determines that it is not necessary to execute the shutdown control until the counted elapsed time Lth reaches the determination time Lth, and when it is determined that the counted elapsed time Ltr has reached the determination time Lth, the shutdown control is performed. Judge that it is necessary to execute. When the shutdown determination unit 58a determines that the execution of the shutdown control is unnecessary, the logic of the shutdown command output to the NOT circuit 58b is set to L. In this case, the logic of the output signal from the NOT circuit 58b to the AND circuit 58c becomes H. On the other hand, when the shutdown determination unit 58a determines that it is necessary to execute the shutdown control, the logic of the shutdown command output to the NOT circuit 58b is set to H. In this case, the logic of the output signal from the NOT circuit 58b to the AND circuit 58c becomes L.

When the logic of the output signal of the NOT circuit 58b is L, the AND circuit 58c sets the logic of the instruction signal Sig output to the modulator 56 to L regardless of the logic of the demagnetization command. In this case, all the drive signals output from the modulator 56 to the upper and lower arm switches SWp and SWn of each phase constituting the inverter 40 are set to OFF commands. As a result, shutdown control is executed.

When the logic of each of the output signal and the demagnetization command of the NOT circuit 58b is H, the AND circuit 58c sets the logic of the instruction signal Sig output to the modulator 56 to H. In this case, the drive signal output from the modulator 56 to the lower arm switch SWn of each phase is an ON command, and the drive signal output from the modulator 56 to the upper arm switch SWp of each phase is an OFF command. It is said that. As a result, three-phase short circuit control is executed.

FIG. 6 is a flowchart showing the procedure of demagnetization control.

In step S10, the host control device 80 determines whether or not an abnormality has occurred in the vehicle 10.

When it is determined by the host control device 80 that an abnormality has occurred in the vehicle 10, in step S11, the necessity determination unit 57 determines whether or not there is an abnormality in the configuration necessary for executing the three-phase short-circuit control and the shutdown control. judge.

If it is determined that there is no abnormality in this configuration, the necessity determination unit 57 proceeds to step S12 and determines whether or not demagnetization of the permanent magnet 34 is necessary. Specifically, the necessity determination unit 57 determines that demagnetization is necessary when any of the above-mentioned first to third conditions is satisfied, and reduces when any of the first to third conditions is not satisfied. It is determined that magnetism is unnecessary.

When the necessity determination unit 57 determines that none of the first to third conditions is satisfied, it determines that demagnetization is unnecessary, and sets the logic of the demagnetization command to L. Then, the demagnetization control is terminated. On the other hand, when it is determined that any of the first to third conditions is satisfied, the necessity determination unit 57 determines that demagnetization is necessary.

In step S13, the necessity determination unit 57 sets the logic of the demagnetization command to H. After that, the shutdown determination unit 58a sets the logic of the shutdown command to be output to the NOT circuit 58b to L until the elapsed time Lth after the logic of the demagnetization command is switched to H becomes the determination time Lth. As a result, the logic of the output signal from the NOT circuit 58b to the AND circuit 58c becomes H, and the logic of the instruction signal Sig output from the AND circuit 58c becomes H. As a result, the three-phase short-circuit control is executed in the inverter 40.

In step S14, when the shutdown determination unit 58a determines that the elapsed time Ltr has reached the determination time Lth, the process proceeds to step S15, and the logic of the shutdown command output to the NOT circuit 58b is set to H. As a result, the logic of the output signal from the NOT circuit 58b to the AND circuit 58c becomes L, and the logic of the instruction signal Sig output from the AND circuit 58c becomes L. As a result, shutdown control is executed in the inverter 40.

In the process shown in FIG. 6, for example, when the host control device 80 determines that the vehicle 10 is being towed by another vehicle, the front wheels 11a and the rear wheels 11b are based on the detection values of the angle detection unit 44, for example. It is determined which of the drive wheels 11 is rotating. Here, of the two rotary electric machines 30, the rotary electric machine that applies the drive torque to the rotating drive wheel 11 is designated as the target rotary electric machine. The inverter control device 50 performs the processes of steps S11 to S15 for the inverter connected to the target rotary electric machine among the two inverters 40.

Further, for example, when the host control device 80 determines that at least one abnormality of each rotary electric machine 30 and each inverter 40 and at least one abnormality of each of the detection units 43 to 48 have occurred, two. Among the rotary electric machines 30, a rotary electric machine capable of applying a drive torque to the drive wheels 11 is selected. Of the two inverters 40, the inverter control device 50 performs the processes of steps S11 to S15 for the inverter connected to the selected rotary electric machine, and power drive control or regeneration for the remaining inverters. Drive control is performed. As a result, the running of the vehicle 10 can be continued as much as possible.

Subsequently, an example of the execution mode of the demagnetization control will be described. Here, a case where an abnormality occurs in the vehicle 10 and the vehicle 10 is towed by another vehicle will be described.

First, it is determined by the host control device 80 that an abnormality has occurred in the vehicle 10. As a result, the command from the host control device 80 to the torque command unit 51 is stopped, and the shutdown control is executed in the inverter 40.

The host control device 80 transmits an abnormality notification signal to the necessity determination unit 57. As a result, the necessity determination unit 57 starts determining whether or not demagnetization is necessary. Before the vehicle 10 is towed, the drive wheel 11 in contact with the road surface does not rotate, so that a counter electromotive voltage is not generated in the coil 31. Therefore, the necessity determination unit 57 determines that the DC current value Ip is equal to or greater than the current threshold value Is, and sets the logic of the demagnetization command to L. In this case, the logic of the instruction signal Sig output from the AND circuit 58c becomes L. As a result, the execution of shutdown control is maintained.

After that, the vehicle 10 is towed and the drive wheels 11 in contact with the road surface rotate. As a result, a countercurrent voltage is generated in the coil 31, and when the countercurrent voltage exceeds the voltage between the terminals of the smoothing capacitor 41, a current flows from the inverter 40 side to the smoothing capacitor 41 side, and the DC current value Ip is negative. Becomes the value of. When the DC current value Ip is lower than the current threshold value Is, the necessity determination unit 57 switches the logic of the demagnetization command to H. The logic of the instruction signal Sigma is maintained at L until the elapsed time Ltr after the logic of the demagnetization command is switched to H reaches the determination time Lth. After that, when the elapsed time Ltr reaches the determination time Lth, the logic of the instruction signal Sig is switched to H. As a result, three-phase short-circuit control is started. As a result, as shown in FIG. 7, the operating point OP starts to move from the start position Ps in a swirling manner as in the case of FIG. The q-axis current value Iq that specifies the start position Ps is a negative value because the counter electromotive voltage exceeds the voltage between the terminals of the smoothing capacitor 41, so that the smoothing capacitor 41 is in a charged state. Because. Further, in the example shown in FIG. 7, the start position Ps exists in the third quadrant in which the d and q-axis current values Id and Iq are negative, but the start position Ps does not necessarily exist in the third quadrant. not.

After that, since the elapsed time Ltr reaches the determination time Lth, the shutdown control is started at the first operating point P1 by the process of step S15. After that, an affirmative determination is made in step S10, a negative determination is made in step S11, and it is further determined that the first condition is satisfied in step S12. Therefore, the process of step S13 restarts the three-phase short-circuit control at the second operating point P2, and then restarts the shutdown control at the third operating point P3.

After that, the three-phase short-circuit control is started at the fourth operating point P4, and then the shutdown control is started at the fifth operating point P5. Then, a negative determination is made in step S12, and the demagnetization control ends at the sixth operating point P6.

In the example shown in FIG. 7, three-phase short-circuit control and shutdown control are repeated. As the number of repetitions of these controls increases, the absolute value of the negative d-axis current Id at the end timing of the three-phase short-circuit control becomes smaller.

In the example shown in FIG. 7, the locus of the operating point OP drawn in the demagnetization control is contained in the third quadrant. However, in the present embodiment, since the switching from the three-phase short-circuit control to the shutdown control is performed based on the elapsed time Ltr, the locus of the operating point OP does not fit in the third quadrant and may be in the second quadrant. possible. Even in this case, the permanent magnet 34 can be demagnetized by the negative d-axis current.

Further, when the three-phase short-circuit control and the shutdown control are repeated in the demagnetization control, as shown in FIG. 8, even if the determination time Lth to be compared with the elapsed time Lth is set shorter than the previous determination time Lth. good. In this case, the duration of the three-phase short-circuit control is shorter than the previous duration of the three-phase short-circuit control. The magnetic flux density of the permanent magnet 34 decreases each time the three-phase short-circuit control is performed. Therefore, by gradually shortening the duration, it is possible to suitably suppress the permanent magnet 34 from being demagnetized too much. Although FIG. 8 shows an example in which the duration Lsdn of the shutdown control is gradually shortened, the duration Lsdn of each time may be constant.

According to the present embodiment described above, the permanent magnet 34 can be irreversibly demagnetized while suppressing the occurrence of failure of the inverter 40 or the like by simple control such as three-phase short circuit control and shutdown control.

When it is determined that the DC current value Ip is smaller than the current threshold value Is, it is determined that the permanent magnet 34 needs to be demagnetized. Therefore, the permanent magnet 34 can be demagnetized before the voltage between the terminals of the smoothing capacitor 41 rises excessively or the high voltage battery 20 becomes overcharged.

When it is determined that the power supply voltage Vb is higher than the voltage threshold value Vth, it is determined that the permanent magnet 34 needs to be demagnetized. Therefore, it can be understood that demagnetization is necessary before the withstand voltage of at least one of the high voltage battery 20, the smoothing capacitor 41, the electric device 42, and the inverter 40 is exceeded. Thereby, the high voltage battery 20, the smoothing capacitor 41, the electric device 42, and the inverter 40 can be protected.

When it is determined that the element temperature Tdr is higher than the temperature threshold value Tds, it is determined that the permanent magnet 34 needs to be demagnetized. Therefore, the components of the inverter 40 can be protected.

When it is determined that the elapsed time Ltr from the start of the three-phase short-circuit control has reached the determination time Lth, the three-phase short-circuit control is switched to the shutdown control. According to this configuration, unlike the determination method in which the electric angle θe is used to determine the start timing of the shutdown control, there is a case where an abnormality occurs in which the electric angle θe cannot be grasped due to a failure of the angle detection unit 44 or the like. However, the start timing of the shutdown control can be properly determined.

After the three-phase short-circuit control and the shutdown control are executed, it is determined again whether or not the permanent magnet 34 needs to be demagnetized. Then, the three-phase short-circuit control and the shutdown control are repeated until it is determined that demagnetization is unnecessary. As a result, for example, even when it is difficult to accurately grasp how much the permanent magnet 34 needs to be demagnetized, the magnetic flux density of the permanent magnet 34 is reduced as much as possible until it reaches a desired density. It can be magnetized.

According to the present embodiment, since the shutdown control is executed in the demagnetization control, it is possible to prevent the permanent magnet 34 from being demagnetized too much, and the components of the coil 31 and the inverter 40 are in an overheated state. Can be prevented. Therefore, the demagnetized rotary electric machine 30 and the inverter 40 can be sold in the aftermarket as relatively high-quality second-hand goods.

<Modified example of the first embodiment>
-In step S12 of FIG. 6, the first condition may be a condition that the sign of the direct current value Ip is negative. Specifically, when the necessity determination unit 57 determines that the sign of the DC current value Ip is positive, it determines that the smoothing capacitor 41 is not in the charged state, and determines that demagnetization is unnecessary. Then, the necessity determination unit 57 sets the logic of the demagnetization command to L. On the other hand, when the necessity determination unit 57 determines that the sign of the DC current value Ip is negative, it determines that the smoothing capacitor 41 is in a charged state, and determines that demagnetization is necessary. Then, the necessity determination unit 57 sets the logic of the demagnetization command to H. When the sign of the DC current value Ip is negative, it is considered that the current is flowing in the high potential side path Lp in the direction in which the smoothing capacitor 41 is charged.

In step S12 of FIG. 6, the first condition may be a condition that the q-axis current value Iqr calculated by the dq conversion unit 53 is smaller than the q-axis current threshold value Iqth. Specifically, when the necessity determination unit 57 determines that the q-axis current value Iqr is equal to or greater than the q-axis current threshold value Iqth, it determines that the smoothing capacitor 41 is not in the charged state, and determines that demagnetization is unnecessary. On the other hand, when the necessity determination unit 57 determines that the q-axis current value Iqr is smaller than the q-axis current threshold value Iqth, it determines that the smoothing capacitor 41 is in a charged state and determines that demagnetization is necessary.

The q-axis current threshold Iqth is set to 0 or a value slightly smaller than 0. Therefore, when the q-axis current value Iqr is smaller than the q-axis current threshold value Iqth, it is considered that the smoothing capacitor 41 is charged.

Incidentally, in this case, it is necessary to use the electric angle θe for calculating the q-axis current value Iqr. Therefore, in step S11, the abnormality of the configuration necessary for executing the three-phase short-circuit control and the shutdown control may include an abnormality that makes it impossible to acquire the electric angle θe and the phase current detection value. The abnormality that makes it impossible to acquire the electric angle θe includes an abnormality of the angle detection unit 44. The abnormality in which the phase current detection value cannot be acquired includes an abnormality in the phase current detection unit 43.

Not only the q-axis current value Iqr but also the d and q-axis current values Idr and Iqr may be used. In this case, when the necessity determination unit 57 determines, for example, that the torque of the rotary electric machine 30 determined from the d, q-axis current values Idr, Iqr is the regenerative torque (<0), the smoothing capacitor 41 is in the charged state. It may be determined that.

Further, the current value for determining whether or not the smoothing capacitor 41 is in the charged state is not limited to the current value in the rotating coordinate system (dq coordinate system), but the current value in the fixed coordinate system (UVW coordinate system) (for example). , The detection value of the phase current detection unit 43). Further, instead of the current value, the line voltage or the phase voltage of the coil 31 may be used.

In step S12 of FIG. 6, the first condition may be a condition that the counter electromotive voltage Vm generated in the coil 31 is higher than the electromotive voltage threshold value Vα. The electromotive voltage threshold value Vα is set to a value lower than, for example, the power supply voltage Vb. When the necessity determination unit 57 determines that the counter electromotive voltage Vm is equal to or less than the electromotive voltage threshold Vα, it determines that the smoothing capacitor 41 is not in the charged state, and determines that demagnetization is unnecessary. On the other hand, when the necessity determination unit 57 determines that the counter electromotive voltage Vm is higher than the electromotive voltage threshold Vα, it determines that the smoothing capacitor 41 is in a charged state and determines that demagnetization is necessary. The necessity determination unit 57 may calculate the counter electromotive voltage Vm based on, for example, the electric angular velocity ωe of the rotor 33. In this case, the necessity determination unit 57 may calculate the electric angular velocity ωe based on the electric angle θe.

In this way, when the counter electromotive voltage Vm is higher than the electromotive voltage threshold Vα, the counter electromotive voltage is higher than the actual terminal-to-terminal voltage of the smoothing capacitor 41, and there is a high possibility that the smoothing capacitor 41 is charged. ..

In step S12 of FIG. 6, a fourth condition that the absolute value of the DC current value Ip is higher than the allowable current value (> 0) may be added. In this case, the necessity determination unit 57 determines that demagnetization is necessary when any of the first to fourth conditions is satisfied, and when none of the first to fourth conditions is satisfied, demagnetization is performed. Determined to be unnecessary.

<Second Embodiment>
Hereinafter, the second embodiment will be described with reference to the drawings, focusing on the differences from the first embodiment. In the present embodiment, the inverter control device 50 sets the determination time Lth used in step S14 of FIG. 6 longer as the magnet temperature Tmag detected by the second temperature detection unit 47 becomes lower, as shown in FIG. This setting is based on the fact that the lower the temperature of the permanent magnet 34, the higher the magnetic flux density of the permanent magnet 34, and it is necessary to increase the degree of demagnetization.

The inverter control device 50 may use the temperature estimation value of the permanent magnet 34 instead of the detection value of the first temperature detection unit 46 for setting the determination time Lth.

<Third Embodiment>
Hereinafter, the third embodiment will be described with reference to the drawings, focusing on the differences from the first embodiment. In the present embodiment, as shown in FIG. 10, the first condition is changed to the condition relating to the electric angular velocity ωe. In FIG. 10, the same processing as that shown in FIG. 6 is designated by the same reference numerals for convenience.

In step S16, the first condition is that the electric angular velocity ωe is higher than the velocity threshold value ωth. This condition is a condition for determining whether or not the smoothing capacitor 41 is in a charged state. The velocity threshold ωth is, for example, between terminals where the counter electromotive voltage of the coil 31 can be taken by a normal high-voltage battery 20 when the temperature of the permanent magnet 34 becomes the lower limit of the possible temperature range (for example, −40 ° C.). It suffices if the electric angular velocity is set to be higher than the lower limit of the voltage range.

When the necessity determination unit 57 determines that the electric angular velocity ωe is equal to or less than the velocity threshold value ωth, the necessity determination unit 57 determines that demagnetization is unnecessary. On the other hand, when the necessity determination unit 57 determines that the electric angular velocity ωe is higher than the velocity threshold value ωth, it determines that demagnetization is necessary. In addition, for example, the mechanical angular velocity of the rotor 33 may be used instead of the electric angular velocity ωe.

<Fourth Embodiment>
Hereinafter, the fourth embodiment will be described with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, as shown in FIG. 11, the first condition is changed to the condition relating to the magnet temperature Tmag. In FIG. 11, the same processing as that shown in FIG. 6 is designated by the same reference numerals for convenience.

In step S17, the first condition is that the magnet temperature Tmag is lower than the magnet threshold Tgs. This condition is a condition for determining whether or not the smoothing capacitor 41 is in a charged state. The magnet threshold Tgth is, for example, when the rotation speed of the rotor 33 becomes the upper limit value (maximum rotation speed) of the possible speed range, the countercurrent voltage of the coil 31 is the voltage between terminals that can be taken by the normal high voltage battery 20. It suffices if the temperature of the permanent magnet 34 is set to be higher than the lower limit of the range.

When the necessity determination unit 57 determines that the magnet temperature Tmag is equal to or higher than the magnet threshold value Tgth, the necessity determination unit 57 determines that demagnetization is unnecessary. On the other hand, when the necessity determination unit 57 determines that the magnet temperature Tmag is lower than the magnet threshold value Tgth, it determines that demagnetization is necessary.

The inverter control device 50 may use the temperature estimation value of the permanent magnet 34 instead of the detection value of the first temperature detection unit 46 as the temperature to be compared with the magnet threshold value Tgs.

<Fifth Embodiment>
Hereinafter, the fifth embodiment will be described with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, as shown in FIG. 12, the condition for switching from the three-phase short-circuit control to the shutdown control is changed. In FIG. 12, the same processing as that shown in FIG. 6 is designated by the same reference numerals for convenience.

In step S18, the necessity determination unit 57 sets the logic of the demagnetization command to H. After that, the shutdown determination unit 58a acquires the d-axis current value Idr, the acquired d-axis current value Idr is a negative value, and the absolute value of the d-axis current value Idr is the d-axis current threshold Idth (>). It is determined whether or not it exceeds 0). If the shutdown determination unit 58a makes an affirmative determination in step S18, the shutdown determination unit 58a switches the logic of the shutdown command output to the NOT circuit 58b from H to L. As a result, shutdown control is executed in step S15.

According to the present embodiment described above, since the d-axis current required for demagnetizing the permanent magnet 34 can be grasped, the permanent magnet 34 can be appropriately demagnetized.

The d-axis current threshold Idth may be reduced each time the three-phase short-circuit control and the shutdown control are repeated in the demagnetization control.

<Sixth Embodiment>
Hereinafter, the sixth embodiment will be described with reference to the drawings, focusing on the differences from the fifth embodiment. In the present embodiment, as shown in FIG. 13, the condition for switching from the three-phase short-circuit control to the shutdown control is changed. In FIG. 13, the same processing as that shown in FIG. 6 is designated by the same reference numerals for convenience.

In step S19, the necessity determination unit 57 sets the logic of the demagnetization command to H. After that, the shutdown determination unit 58a acquires the q-axis current value Iqr, and determines whether or not the acquired q-axis current value Iqr has switched from a negative value to a positive value. When the shutdown determination unit 58a determines affirmatively in step S19, it determines that the rotary electric machine 30 has switched from the power generation state to the power running state, and switches the logic of the shutdown command output to the NOT circuit 58b from H to L. As a result, shutdown control is executed in step S15.

According to the present embodiment described above, the demagnetization control can be executed only during the period in which the voltage between the terminals of the smoothing capacitor 41 is expected to increase.

<Other embodiments>
In addition, each of the above-mentioned embodiments may be changed and carried out as follows.

The three-phase short-circuit control may be a control in which the upper arm switch SWp of all phases is turned on and the lower arm switch SWn of all phases is turned off.

As shown in FIG. 14, in each phase, a connection switch SWφ may be provided between the connection points of the upper and lower arm switches SWp and SWn and the first end of the coil 31. In this case, in step S15 of FIG. 6, the inverter control device 50 may execute a control (corresponding to “cutoff control”) for turning off the connection switch SWφ of each phase instead of the shutdown control.

-The demagnetization control is not limited to the one that irreversibly demagnetizes the permanent magnet 34. For example, in the demagnetization control, a negative d-axis current capable of reversibly demagnetizing the permanent magnet 34 may be passed.

-The switch constituting the inverter is not limited to the IGBT, and may be, for example, an N-channel MOSFET having a built-in body diode.

-The rotary electric machine and the inverter are not limited to three-phase ones, but may be two-phase ones or four-phase or more ones. Further, the rotary electric machine is not limited to the on-board motor, but may be an in-wheel motor built in the wheel.

-The vehicle is not limited to a four-wheel drive vehicle, and for example, any one of the front wheels 11a and the rear wheels 11b may be a drive wheel.

-The moving body on which the control system is mounted is not limited to a vehicle, and may be, for example, an aircraft or a ship. For example, when the moving body is an aircraft, the rotating electric machine constituting the control system is the flight power source of the aircraft. Further, for example, when the moving body is a ship, the rotary electric machine constituting the control system becomes a navigation force source of the ship.

The controls and methods thereof described in the present disclosure are provided by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. It may be realized. Alternatively, the controls and methods thereof described in the present disclosure may be implemented by a dedicated computer provided by configuring the processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and method thereof described in the present disclosure may be a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. It may be realized by one or more dedicated computers configured. Further, the computer program may be stored in a computer-readable non-transitional tangible recording medium as an instruction executed by the computer.

10 ... vehicle, 20 ... high voltage battery, 30 ... rotary electric machine, 40 ... inverter, 50 ... inverter control device, 57 ... necessity determination unit, 58 ... demagnetization execution unit, SWp, SWn ... upper, lower arm switch.

Claims (13)

Power storage unit (20, 41) and
A rotary electric machine (30) having a rotor (33) having a permanent magnet (34) and a stator (32) having a multi-phase coil (31) and serving as a moving power source for the moving body (10).
An inverter (40) having upper and lower arm switches (SWp, SWn) in which diodes (Dp, Dn) are connected in antiparallel connection and electrically connecting the power storage unit and the coil.
In the inverter control device (50) applied to the system including
The necessity determination unit (57) for determining whether or not demagnetization of the permanent magnet is necessary, and
When it is determined by the necessity determination unit that demagnetization is necessary, one of the upper and lower arm switches (SWn) is turned on in all phases, and the other arm switch (SWp) is turned on. By turning off all phases, a short-circuit control is executed in which a recirculation current is passed through the closed circuit including the arm switch and the coil that are turned on, and after the short-circuit control is executed, a cutoff control is performed so that the recirculation current does not flow. An inverter control device including a demagnetization execution unit (58) for performing the above. The necessity determination unit determines whether or not demagnetization is necessary again after the short circuit control and the cutoff control are executed by the demagnetization execution unit.
The inverter control device according to claim 1, wherein the demagnetization execution unit repeats execution of the short-circuit control and the cutoff control until it is determined by the necessity determination unit that demagnetization is unnecessary. The inverter control device according to claim 2, wherein the demagnetization execution unit shortens the duration (Lth) of the short-circuit control to be shorter than the duration of the previous short-circuit control. The inverter control device according to any one of claims 1 to 3, wherein the demagnetization execution unit lengthens the duration (Lth) of the short-circuit control as the temperature (Tmag) of the permanent magnet is lower. The necessity determination unit determines that demagnetization is necessary when it is determined that the voltage (Vb) of the power storage unit exceeds the voltage threshold (Vth) lower than the withstand voltage of the power storage unit. The inverter control device according to any one of 4 to 4. The inverter control device according to any one of claims 1 to 5, wherein the necessity determination unit determines that demagnetization is necessary on condition that the power storage unit is determined to be in a charged state. The necessity determination unit includes a direct current (Ip) flowing between the power storage unit and the inverter, a countercurrent voltage (Vm) output from the coil via the inverter, and a rotation speed (ωe) of the rotor. The inverter control device according to claim 6, wherein it is determined whether or not the power storage unit is in a charged state based on the temperature (Tmag) of the permanent magnet. The necessity determination unit determines that demagnetization is necessary when the temperature (Tdr) of the diode, the upper arm switch or the lower arm switch is higher than the temperature threshold value (Tds), claims 1 to 7. The inverter control device according to any one of the above items. The necessity determination unit determines whether or not demagnetization is necessary on condition that the upper control device (80) provided outside the inverter control device instructs the demagnetization determination of the permanent magnet. The inverter control device according to any one of claims 1 to 8. Any one of claims 1 to 9, wherein the demagnetization execution unit starts the cutoff control when it is determined that the elapsed time (Ltr) from the start of the short circuit control has reached the determination time (Lth). The inverter control device according to item 1. The demagnetization execution unit starts the short-circuit control, and then starts the cutoff control when it is determined that the d-axis current (Idr) for field weakening exceeds the d-axis current threshold value (Idth). The inverter control device according to any one of 1 to 9. The demagnetization execution unit, after starting the short-circuit control, starts the cutoff control when it is determined that the rotary electric machine has switched from the power generation state to the power running state, according to any one of claims 1 to 9. Inverter control device. The inverter control device according to any one of claims 1 to 12, wherein the cutoff control is a control for turning off the upper and lower arm switches of all phases.

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