JP2009159663A - Motor drive device, electric vehicle, and method of controlling motor drive devices - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor drive device including multiple converters connected in parallel wherein the production of overvoltage can be prevented when a system is brought to an emergency stop. <P>SOLUTION: A first converter 10-1 and a second converter 10-2 are respectively connected in parallel with a capacitor C. Each converter is comprised of a direct-current chopper circuit. When a system emergency stop is requested, a first inverter 20-1, a second inverter 20-2, and the second converter 10-2 are immediately stopped. The first converter 10-1 continues operation only for a predetermined time. By this arrangement, a power storage device B1 absorbs power flowing from a motor coil or the reactor of a converter into the capacitor C as the result of the system stop. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electric motor drive device including a plurality of converters connected in parallel, an electric vehicle, and an electric motor drive device control method.

  In recent years, in electric vehicles equipped with an electric motor as a power source such as a hybrid vehicle and an electric vehicle (Electric Vehicle), the capacity of the power supply device has been increased in order to improve the running performance such as acceleration performance and running distance. Yes. And the structure which has a some electrical storage part is proposed as a means for enlarging capacity | capacitance of a power supply device.

  For example, Japanese Patent Laying-Open No. 2003-209969 (Patent Document 1) discloses a power supply control system including a plurality of power supply stages. The power supply control system includes a plurality of power supply stages that are connected in parallel to each other and supply DC power to at least one inverter. Each power supply stage includes a battery and a boost / buck DC-DC converter composed of a DC chopper circuit.

In this power supply control system, the plurality of power supply stages are controlled so as to maintain the output voltage to the inverter by uniformly charging and discharging a plurality of batteries respectively included in the plurality of power supply stages (see Patent Document 1). ).
JP 2003-209969 A Japanese Patent Laid-Open No. 10-164709 JP 2003-230269 A JP 2005-20952 A JP 2004-159401 A

  When the system is stopped urgently in the above power supply control system, the energy stored in the coils of each motor and the coils included in each power supply stage flows into the filter capacitor provided on the DC bus, and the filter capacitor is overvoltage. May cause destruction. However, in the above-mentioned Japanese Patent Application Laid-Open No. 2003-209969, measures for preventing the overvoltage of the filter / capacitor when the system is urgently stopped are not particularly studied.

  Accordingly, the present invention has been made to solve such a problem, and an object of the present invention is to prevent the occurrence of an overvoltage at the time of emergency stop of a system in an electric motor drive device including a plurality of converters connected in parallel. An electric motor drive device and an electric vehicle including the same are provided.

  Another object of the present invention is to provide a method for controlling an electric motor drive device capable of preventing occurrence of an overvoltage when the system is urgently stopped in an electric motor drive device including a plurality of converters connected in parallel.

  According to this invention, the electric motor drive device is an electric motor drive device capable of driving the electric motor, and includes a drive circuit, first and second converters, a capacitor, and a control device. The drive circuit is configured to be able to drive at least one electric motor. The first converter is provided between the rechargeable first power storage device and a DC power line connected to the drive circuit, and is configured to be capable of voltage conversion between the first power storage device and the DC power line. . The second converter is provided between the rechargeable second power storage device and the DC power line, and is configured to be capable of voltage conversion between the second power storage device and the DC power line. The capacitor smoothes the voltage of the DC power line. The control device controls the first and second converters and the drive circuit. Each of the first and second converters includes a DC chopper circuit including at least one switching element and a reactor capable of storing energy. The control device continues the control of one of the first and second converters after the system stop request when the system of the motor drive device is stopped.

  Preferably, the control device estimates a state quantity indicating a charging state of each of the first and second power storage devices, and the state quantity of the power storage device corresponding to the converter to be controlled after the system stop request is an upper limit value. Is reached, the converter that has continued control is stopped and the other converter is operated.

  More preferably, the electric motor drive device further includes a discharge resistor and a relay. The discharge resistor is provided in parallel with the capacitor. The relay is connected in series with the discharge resistor. Then, the control device turns on the relay when the state quantities of the first and second power storage devices reach the upper limit value.

  More preferably, the electric motor drive device further includes an auxiliary machine. The auxiliary machine is connected between the first power storage device and the first converter or between the second power storage device and the second converter. Then, the control device drives the auxiliary machine when the state quantities of the first and second power storage devices reach the upper limit value.

  Preferably, the control device estimates a state quantity indicating a state of charge of each of the first and second power storage devices, and responds to a lower one of the first and second power storage devices after the system stop request. Continue to control the converter.

  Preferably, the control device controls the voltage of the first converter so that the voltage of the DC power line becomes the target voltage, and controls the current of the second converter so that the charge / discharge current of the second power storage device becomes the target current. Then, after the system stop request, the control of the first converter is continued.

  More preferably, the control device is configured to be switchable between current control of the second converter or voltage control of the second converter so that the voltage of the DC power line becomes the target voltage, and at the time of a system stop request. When the first converter is abnormal, the control of the first converter is stopped and the voltage of the second converter is controlled.

  Preferably, the control device generates a current command for controlling the voltage of the DC power line to the target voltage, distributes the current command to the first and second current commands according to a predetermined distribution ratio, and the first power storage device The first converter is current-controlled so that the charge / discharge current of the second power storage device matches the first current command, and the second converter current is controlled so that the charge / discharge current of the second power storage device matches the second current command. After the control and the system stop request, the control of the first converter is continued and the distribution ratio is set so that the distribution ratio of the first current command becomes 100%.

  According to the present invention, an electric vehicle includes any one of the above-described electric motor drive devices and drive wheels driven by at least one electric motor.

  Further, according to the present invention, the control method is a control method for an electric motor drive device capable of driving an electric motor. The electric motor drive device includes a drive circuit, first and second converters, and a capacitor. The drive circuit is configured to be able to drive at least one electric motor. The first converter is provided between the rechargeable first power storage device and a DC power line connected to the drive circuit, and is configured to be capable of voltage conversion between the first power storage device and the DC power line. . The second converter is provided between the rechargeable second power storage device and the DC power line, and is configured to be capable of voltage conversion between the second power storage device and the DC power line. The capacitor smoothes the voltage of the DC power line. Each of the first and second converters includes a DC chopper circuit including at least one switching element and a reactor capable of storing energy. The control method includes a first step for determining whether or not a system stop of the electric motor drive device is requested, and when it is determined that the system stop is requested, the drive circuit is stopped and the first and second steps are stopped. A second step of stopping one of the converters and a third step of continuing control of the other converter for a specified time after the system stop request is included.

  Preferably, the first converter is voltage-controlled so that the voltage of the DC power line becomes the target voltage. The second converter is current-controlled so that the charge / discharge current of the second power storage device becomes a target current. Then, in the second step, the second converter is stopped, and in the third step, control of the first converter is continued for a specified time after the system stop request.

  In the present invention, the first and second converters are connected in parallel to the DC power line. Each of the first and second converters includes a DC chopper circuit including at least one switching element and a reactor capable of storing energy. And, when the system of the motor drive device is stopped, control of either one of the first and second converters is continued after the system stop request, so that the electric power flowing into the capacitor from the motor coil or reactor when the system is stopped, It can be absorbed by the power storage device corresponding to the converter for which control is continued.

  Therefore, according to the present invention, it is possible to prevent an overvoltage that can be generated by the energy stored in the coil or reactor of the motor when the system of the motor driving device is stopped.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is an overall configuration diagram of a hybrid vehicle shown as an example of an electric vehicle equipped with an electric motor drive device according to Embodiment 1 of the present invention. Referring to FIG. 1, hybrid vehicle 100 includes an engine 2, a first motor generator MG 1, a second motor generator MG 2, a power split mechanism 4, and drive wheels 6. Hybrid vehicle 100 includes power storage devices B1 and B2, first converter 10-1, second converter 10-2, main positive bus MPL, main negative bus MNL, capacitor C, and first inverter 20. -1, a second inverter 20-2, and an ECU (Electronic Control Unit) 30 are further provided. Furthermore, hybrid vehicle 100 further includes voltage sensors 32, 42-1, 42-2, current sensors 44-1, 44-2, and temperature sensors 46-1, 46-2.

  This hybrid vehicle 100 runs using engine 2 and second motor generator MG2 as power sources. Power split device 4 is coupled to engine 2, first motor generator MG1, and second motor generator MG2, and distributes power among them. Power split device 4 is composed of, for example, a planetary gear mechanism having three rotation shafts of a sun gear, a planetary carrier, and a ring gear, and these three rotation shafts are the rotation shafts of engine 2, first motor generator MG1, and second motor generator MG2. Connected to each. The rotor of first motor generator MG1 is hollow and the crankshaft of engine 2 is passed through the center thereof, so that engine 2, first motor generator MG1 and second motor generator MG2 are mechanically connected to power split mechanism 4. can do. The rotation shaft of second motor generator MG2 is connected to drive wheel 6 via a reduction gear and a differential gear (not shown).

  First motor generator MG1 operates as a generator driven by engine 2 and is incorporated in hybrid vehicle 100 as an electric motor that can start engine 2, and second motor generator MG2 is It is incorporated in the hybrid vehicle 100 as an electric motor that drives the drive wheels 6.

  The power storage devices B1 and B2 are rechargeable DC power sources, and include, for example, secondary batteries such as nickel metal hydride and lithium ions. The power storage device B1 supplies power to the first converter 10-1, and is charged by the first converter 10-1 during power regeneration. The power storage device B2 supplies power to the second converter 10-2, and is charged by the second converter 10-2 during power regeneration. Note that a large-capacity capacitor may be used for at least one of the power storage devices B1 and B2.

  First converter 10-1 is connected between power storage device B1, main positive bus MPL, and main negative bus MNL. First converter 10-1 includes switching elements Q11 and Q12, diodes D11 and D12, a reactor L1, and a capacitor C1. Switching elements Q11, Q12 are connected in series between main positive bus MPL and main negative bus MNL. Diodes D11 and D12 are connected in antiparallel to switching elements Q11 and Q12, respectively. Reactor L1 is connected between a connection node of switching elements Q11 and Q12 and positive line PL1 connected to the positive electrode of power storage device B1. Capacitor C1 is connected between positive line PL1 and main negative bus MNL.

  First converter 10-1 performs voltage conversion between power storage device B1, main positive bus MPL, and main negative bus MNL based on signal PWC1 from ECU 30. In addition, when first converter 10-1 receives signal SDC1 from ECU 30, first converter 10-1 shuts off the gates of switching elements Q11 and Q12.

  Second converter 10-2 is connected between power storage device B2 and main positive bus MPL and main negative bus MNL. Second converter 10-2 includes switching elements Q21 and Q22, diodes D21 and D22, a reactor L2, and a capacitor C2. Switching elements Q21, Q22 are connected in series between main positive bus MPL and main negative bus MNL. Diodes D21 and D22 are connected in antiparallel to switching elements Q21 and Q22, respectively. Reactor L2 is connected between a connection node of switching elements Q21 and Q22 and positive line PL2 connected to the positive electrode of power storage device B2. Capacitor C2 is connected between positive line PL2 and main negative bus MNL.

  Second converter 10-2 performs voltage conversion between power storage device B2, main positive bus MPL, and main negative bus MNL based on signal PWC2 from ECU 30. In addition, when second converter 10-2 receives signal SDC2 from ECU 30, second converter 10-2 blocks the gates of switching elements Q21 and Q22 and stops its operation.

  As the switching element, for example, an IGBT (Insulated Gate Bipolar Transistor), a power MOSFET (Metal Oxide Semiconductor Field-Effect Transistor), or the like can be used.

  Capacitor C is connected between main positive bus MPL and main negative bus MNL, and smoothes a voltage fluctuation component between main positive bus MPL and main negative bus MNL.

  Each of first inverter 20-1 and second inverter 20-2 includes, for example, a bridge circuit including switching elements for three phases. First inverter 20-1 converts a DC voltage from main positive line MPL into a three-phase AC voltage based on signal PWI1 from ECU 30, and outputs the converted three-phase AC voltage to first motor generator MG1. First inverter 20-1 converts the three-phase AC voltage generated by first motor generator MG1 using the power of engine 2 into a DC voltage based on signal PWI1, and converts the converted DC voltage to the main positive bus. Output to MPL. In addition, the 1st inverter 20-1 will interrupt | block the operation | movement by interrupting | blocking the gate of each switching element, if the signal SDI1 is received from ECU30.

  Second inverter 20-2 converts a DC voltage from main positive bus MPL into a three-phase AC voltage based on signal PWI2 from ECU 30, and outputs the converted three-phase AC voltage to second motor generator MG2. The second inverter 20-2 receives the three-phase AC voltage generated by the second motor generator MG2 by receiving the rotational force from the drive wheels 6 when the vehicle is braked or when the acceleration on the down slope is reduced, based on the signal PWI2. To a DC voltage, and the converted DC voltage is output to the main positive bus MPL. Note that, when the second inverter 20-2 receives the signal SDI2 from the ECU 30, the second inverter 20-2 blocks the gate of each switching element and stops its operation.

  Each of first motor generator MG1 and second motor generator MG2 is a three-phase AC motor, for example, a three-phase AC synchronous motor generator. First motor generator MG1 includes a three-phase coil 7 as a stator coil. First motor generator MG1 is regeneratively driven by first inverter 20-1, and outputs a three-phase AC voltage generated using the power of engine 2 to first inverter 20-1. The first motor generator MG1 is driven by the first inverter 20-1 when the engine 2 is started, and cranks the engine 2.

  Second motor generator MG2 includes a three-phase coil 8 as a stator coil. The second motor generator MG2 is driven by the second inverter 20-2 to generate a driving force for driving the driving wheels 6. Further, the second motor generator MG2 generates a three-phase AC voltage generated by using the rotational force received from the driving wheels 6 that is regeneratively driven by the second inverter 20-2 when the vehicle is braked or when the acceleration on the down slope is reduced. Output to the second inverter 20-2.

  Voltage sensor 32 detects a voltage between terminals of capacitor C, that is, voltage VH between main positive bus MPL and main negative bus MNL, and outputs the detected value to ECU 30. Voltage sensor 42-1 detects voltage VB1 of power storage device B1, and outputs the detected value to ECU 30. Current sensor 44-1 detects current IB1 input / output to / from power storage device B1, and outputs the detected value to ECU 30. Temperature sensor 46-1 detects temperature TB1 of power storage device B1, and outputs the detected value to ECU 30. Voltage sensor 42-2 detects voltage VB2 of power storage device B2 and outputs the detected value to ECU 30. Current sensor 44-2 detects current IB2 input / output to / from power storage device B2, and outputs the detected value to ECU 30. Temperature sensor 46-2 detects temperature TB2 of power storage device B2, and outputs the detected value to ECU 30.

  For currents IB1 and IB2, a positive value is set when current is output from the corresponding power storage device (during discharging), and a negative value is set when current is input to the power storage device (during charging).

  ECU 30 generates signals PWC1 and PWC2 for driving first converter 10-1 and second converter 10-2, respectively, and outputs them to first converter 10-1 and second converter 10-2. Further, ECU 30 generates signals PWI1 and PWI2 for driving first inverter 20-1 and second inverter 20-2, respectively, and outputs them to first inverter 20-1 and second inverter 20-2.

  Here, when an emergency stop of the system is requested, the ECU 30 immediately outputs signals SDI1, SDI2, and SDC2 for stopping the first inverter 20-1, the second inverter 20-2, and the second converter 10-2, respectively. It is generated and output to the first inverter 20-1, the second inverter 20-2, and the second converter 10-2. On the other hand, for the first converter 10-1, the ECU 30 generates a signal PWC1 for driving the first converter 10-1 for a specified time after the system stop request and outputs the signal PWC1 to the first converter 10-1. And ECU30 produces | generates the signal SDC1 for stopping the 1st converter 10-1, and outputs it to the 1st converter 10-1 after progress of regulation time.

  That is, when an emergency stop of the system is requested, the ECU 30 immediately stops the operation of the first inverter 20-1, the second inverter 20-2, and the second converter 10-2. For the above, the operation is continued for a specified time after the system stop request, and the operation is stopped after the specified time elapses. As a result, the energy stored in the three-phase coil 7 of the first motor generator MG1, the three-phase coil 8 of the second motor generator MG2, and the reactor L2 of the second converter 10-2 becomes a capacitor accompanying the emergency stop of the system. Even if it flows into C, the energy can be absorbed by the power storage device B1 when the first converter 10-1 continues to operate. Therefore, it is possible to prevent an overvoltage from being applied to the capacitor C.

  The specified time is a time required for releasing the energy stored in the three-phase coil and the reactor, and is set based on the constants of the three-phase coils 7 and 8 and the reactors L1 and L2.

  In the above description, the converter that continues the operation after the system stop request is used as the first converter 10-1 because the first converter 10-1 is voltage-controlled as will be described later. As described in the second embodiment, even if a converter that is operated independently after a system stop request is current-controlled, it is possible to prevent the voltage VH from becoming an overvoltage by incorporating an overvoltage prevention logic. It is possible.

  FIG. 2 is a functional block diagram of ECU 30 shown in FIG. Referring to FIG. 2, ECU 30 includes a stop control unit 110, a converter control unit 120, a first inverter control unit 130, and a second inverter control unit 140.

  When an emergency stop of the system is requested, stop control unit 110 receives signals STPC2, STPI1, and STPI2 for instructing stop of second converter 10-2, first inverter 20-1, and second inverter 20-2, respectively. Is immediately output to the converter control unit 120, the first inverter control unit 130, and the second inverter control unit 140.

  Stop control unit 110 generates a signal STPC1 for instructing stop of first converter 10-1 and outputs it to converter control unit 120 when a specified time has elapsed after the system stop request.

  Converter control unit 120 generates a PWM (Pulse Width Modulation) signal for turning on / off switching elements Q11 and Q12 of first converter 10-1 based on the detected values of voltages VB1 and VH and current IB1, which will be described later. Generated according to the control structure, and outputs the generated PWM signal as signal PWC1 to first converter 10-1.

  Further, converter control unit 120 generates a PWM signal for turning on / off switching elements Q21 and Q22 of second converter 10-2 based on the detected values of voltages VB2 and VH and current IB2 in accordance with a control structure described later. The generated PWM signal is output to the second converter 10-2 as the signal PWC2.

  In addition, upon receiving signal STPC1 from stop control unit 110, converter control unit 120 generates signal SDC1 for stopping first converter 10-1, and outputs the signal SDC1 to first converter 10-1. Further, upon receiving signal STPC2 from stop control unit 110, converter control unit 120 generates signal SDC2 for stopping second converter 10-2 and outputs the signal to second converter 10-2.

  The first inverter control unit 130 performs the first based on the torque command value TR1 of the first motor generator MG1, the detected values of the motor current MCRT1 and the rotor rotation angle θ1 of the first motor generator MG1, and the detected value of the voltage VH. A PWM signal for turning on / off the switching element included in the inverter 20-1 is generated, and the generated PWM signal is output to the first inverter 20-1 as a signal PWI1.

  Further, when receiving the signal STPI1 from the stop control unit 110, the first inverter control unit 130 generates a signal SDI1 for stopping the first inverter 20-1, and outputs the signal SDI1 to the first inverter 20-1.

  The second inverter control unit 140 performs the second based on the torque command value TR2 of the second motor generator MG2, the detected values of the motor current MCRT2 and the rotor rotation angle θ2 of the second motor generator MG2, and the detected value of the voltage VH. A PWM signal for turning on / off the switching element included in the inverter 20-2 is generated, and the generated PWM signal is output to the second inverter 20-2 as a signal PWI2.

  In addition, when receiving the signal STPI2 from the stop control unit 110, the second inverter control unit 140 generates a signal SDI2 for stopping the second inverter 20-2 and outputs the signal SDI2 to the second inverter 20-2.

  Torque command values TR1 and TR2 are calculated by a vehicle ECU (not shown) based on, for example, the accelerator opening, the brake depression amount, the vehicle speed, and the like. Motor currents MCRT1 and MCRT2 and rotor rotation angles θ1 and θ2 are detected by sensors (not shown).

  FIG. 3 is a detailed functional block diagram of converter control unit 120 shown in FIG. Referring to FIG. 3, converter control unit 120 includes a setting unit 210 and signal generation units 220-1 and 220-2.

  Setting unit 210 sets target value VR of voltage VH and target value IR2 of current IB2. For example, setting unit 210 sets a predetermined voltage higher than voltages VB1 and VB2 as target value VR. In addition, setting unit 210 calculates a power target value of second converter 10-2 by, for example, multiplying the required power for power storage devices B1 and B2 by a predetermined sharing ratio, and uses the calculated power target value as a voltage. A target value IR2 is calculated by dividing by VB2.

  Further, setting unit 210 outputs signal SDC1 to first converter 10-1 when signal STPC1 is received from stop control unit 110 (FIG. 2), and signal SDC2 to second converter 10-2 when signal STPC2 is received. Is output.

  Signal generator 220-1 includes subtractors 222-1 and 226-1, proportional-integral controller 224-1, and modulator 228-1. Subtraction unit 222-1 subtracts voltage VH from target value VR set by setting unit 210, and outputs the calculation result to proportional-integral control unit 224-1. The proportional-plus-integral control unit 224-1 performs a proportional-integral calculation with the deviation between the target value VR and the voltage VH as an input, and outputs the calculation result to the subtracting unit 226-1. The subtracting unit 222-1 and the proportional-plus-integral control unit 224-1 constitute a voltage feedback control element.

  Subtraction unit 226-1 subtracts the output of proportional integration control unit 224-1 from the inverse of the theoretical boost ratio of first converter 10-1 indicated by voltage value VB1 / target value VR, and uses the calculation result as a duty command. It outputs to the modulation | alteration part 228-1.

  Modulation section 228-1 generates signal PWC1 based on the duty command received from subtraction section 226-1 and a carrier wave (carrier wave) generated by an oscillating section (not shown), and first generates the generated signal PWC1. Output to switching elements Q11 and Q12 of converter 10-1.

  Note that, when the signal generation unit 220-1 receives the signal STPC1 from the stop control unit 110, the signal generation unit 220-1 stops generating the signal PWC1.

  The signal generation unit 220-2 includes subtraction units 222-2 and 226-2, a proportional integration control unit 224-2, and a modulation unit 228-2. Subtraction unit 222-2 subtracts current IB2 from target value IR2 set by setting unit 210, and outputs the calculation result to proportional-integral control unit 224-2. The proportional-plus-integral control unit 224-2 performs a proportional-integral calculation with the deviation between the target value IR2 and the current IB2 as an input, and outputs the calculation result to the subtracting unit 226-2. The subtracting unit 222-2 and the proportional-plus-integral control unit 224-2 constitute a current feedback control element.

  Subtraction unit 226-2 subtracts the output of proportional integration control unit 224-2 from the inverse of the theoretical boost ratio of second converter 10-2 indicated by voltage value VB2 / target value VR, and uses the calculation result as a duty command. It outputs to the modulation part 228-2.

  Modulation section 228-2 generates signal PWC2 based on the duty command received from subtraction section 226-2 and a carrier wave (carrier wave) generated by an oscillating section (not shown), and generates the generated signal PWC2 as a second signal. Output to switching elements Q21 and Q22 of converter 10-2.

  In addition, when the signal generation unit 220-2 receives the signal STPC2 from the stop control unit 110, the signal generation unit 220-2 stops generating the signal PWC2.

  FIG. 4 is a flowchart related to the system stop process performed by the ECU 30 shown in FIG. Note that the processing of this flowchart is executed at regular time intervals or whenever a predetermined condition is satisfied. Referring to FIG. 4, ECU 30 determines whether or not an emergency stop of the system has been requested (step S10). If it is determined that an emergency stop of the system is not requested (NO in step S10), the process proceeds to step S50.

  If it is determined in step S10 that an emergency stop of the system has been requested (YES in step S10), ECU 30 generates signals SDI1, SDI2, and SDC2, and generates first inverter 20-1, second inverter 20-2, and second inverter 20-2. 2 The converter 10-2 is stopped (step S20).

  Thereafter, ECU 30 determines whether or not the specified time has elapsed since the emergency stop of the system was requested (step S30), and determines that the specified time has elapsed (YES in step S30), generates signal SDC1. Then, the first converter 10-1 is stopped (step S40).

  As described above, in the first embodiment, at the time of an emergency stop of the system, the control of the first converter 10-1 is continued for a specified time after the system stop request. The electric power flowing into the capacitor C from the reactor can be absorbed by the power storage device B1. Therefore, according to the first embodiment, it is possible to prevent an overvoltage that can be generated by the energy stored in the motor coil or the reactor of the converter during an emergency stop of the system.

[Embodiment 2]
In the second embodiment, after the emergency stop of the system, the operation of voltage-controlled first converter 10-1 is continued, and the state of charge of power storage device B1 (hereinafter also referred to as “SOC (State Of Charge)”). When the upper limit is reached, the first converter 10-1 is stopped and the second converter 10-2 is operated.

  FIG. 5 is a functional block diagram of ECU 30A in the second embodiment. Referring to FIG. 5, ECU 30A further includes an SOC estimation unit 150 in the configuration of ECU 30 in the first embodiment shown in FIG. 2, and replaces stop control unit 110 and converter control unit 120 with stop control unit 110A. And converter control unit 120A.

  Based on voltage VB1, current IB1, and temperature TB1 of power storage device B1, SOC estimation unit 150 represents a state quantity SOC1 (represented by 0 to 100% of the fully charged state) indicating the SOC of power storage device B1. The estimated state quantity SOC1 is output to the stop control unit 110A. Further, SOC estimation unit 150 estimates state quantity SOC2 indicating the SOC of power storage device B2 based on voltage VB2, current IB2 and temperature TB2 of power storage device B2, and uses the estimated state quantity SOC2 as stop control unit 110A. Output to. Various known methods can be used for the SOC estimation method.

  When an emergency stop of the system is requested, stop control unit 110A generates signals STPC2, STPI1, and STPI2 and immediately outputs them to converter control unit 120, first inverter control unit 130, and second inverter control unit 140.

  Here, stop control unit 110A permits operation of first inverter 10-1 even after the system stop request. When state quantity SOC1 of power storage device B1 reaches the upper limit value, signal STPC1 is converted to converter control unit 110A. Output to 120A and stop outputting the signal STPC2. Then, stop control unit 110A outputs signal STPC2 to converter control unit 120A when the specified time has elapsed after the system stop request.

  FIG. 6 is a functional block diagram of converter control unit 120A shown in FIG. Referring to FIG. 6, converter control unit 120A further includes a current command limiting unit 230 in the configuration of converter control unit 120 in the first embodiment shown in FIG.

  Current command limiting unit 230 receives target value IR2 of current IB2, voltage VH, and signal STPC1. When the current command limiter 230 receives the signal STPC1, that is, when the state quantity SOC1 reaches the upper limit value after the system emergency stop request, the current command limiter 230 uses the map described later to determine the current IB2 based on the voltage VH. The upper limit value of the target value IR2 is variably set.

  FIG. 7 is a diagram showing an upper limit setting of target value IR2 of current IB2 by current command limiting unit 230 shown in FIG. Referring to FIG. 7, when voltage VH is lower than voltage V1, upper limit value of target value IR2 is set to L1. When voltage VH exceeds voltage V1, the upper limit value of target value IR2 is reduced. When voltage VH is equal to or higher than voltage V2, the upper limit value of target value IR2 is set to L2 (negative value).

  That is, second converter 10-2 that operates after the SOC of power storage device B1 reaches the upper limit value is current controlled. When voltage VH is low, discharge from power storage device B2 is permitted, and voltage VH is When the voltage is high, the target value IR2 (negative value) in the direction in which the current flows into the power storage device B2 is forcibly generated, thereby preventing the voltage VH from becoming an overvoltage. That is, the current command limiting unit 230 corresponds to an overvoltage prevention logic in the second converter 10-2 that is current controlled.

  FIG. 8 is a diagram showing a flowchart regarding system stop processing by ECU 30A in the second embodiment. Note that the processing of this flowchart is also executed at regular time intervals or whenever a predetermined condition is satisfied. Referring to FIG. 8, this flowchart further includes steps S22 and S24 in the flowchart shown in FIG. 4, and includes step S45 instead of step S40.

  That is, when first inverter 20-1, second inverter 20-2, and second converter 10-2 are stopped in step S20, ECU 30A determines whether state quantity SOC1 of power storage device B1 is equal to or greater than the upper limit value. Is determined (step S22). When it is determined that state quantity SOC1 is equal to or greater than the upper limit value (YES in step S22), ECU 30A stops first converter 10-1 and operates second converter 10-2 (step S24). Specifically, ECU 30A generates signal SDC1 and outputs it to first converter 10-1, stops output of signal SDC2 to second converter 10-2, and generates signal PWC2 to generate the second converter. Output to 10-2.

  On the other hand, if it is determined in step S22 that state quantity SOC1 is lower than the upper limit value (NO in step S22), ECU 30A proceeds to step S30 without executing step S24.

  If it is determined in step S30 that the specified time has elapsed (YES in step S30), ECU 30A stops first converter 10-1 or second converter 10-2 that is operating at that time (step S30). S45). If it is determined in step S30 that the specified time has not elapsed (NO in step S30), the process returns to step S22.

  As described above, in the second embodiment, after the system stop request, when state quantity SOC1 of power storage device B1 reaches the upper limit value, first converter 10-1 is stopped and second converter 10-2 is operated. Let When second converter 10-2 operates after a system stop request, current control is performed by current command limiter 230 so as to prevent overvoltage of voltage VH. Therefore, according to the second embodiment, overvoltage can be prevented even when the SOC of power storage device B1 reaches the upper limit during an emergency stop of the system.

[Embodiment 3]
FIG. 9 is an overall configuration diagram of a hybrid vehicle shown as an example of an electric vehicle equipped with the electric motor drive device according to the third embodiment. Referring to FIG. 9, this hybrid vehicle 100 </ b> A further includes a discharge resistor 34 and a relay 36 in the configuration of hybrid vehicle 100 shown in FIG. 1, and includes an ECU 30 </ b> B instead of ECU 30.

  Discharge resistor 34 and relay 36 are connected in series between main positive bus MPL and main negative bus MNL. Relay 36 is turned on / off based on signal SE from ECU 30B. When relay 36 is turned on, discharge resistor 34 is electrically connected between main positive bus MPL and main negative bus MNL, and reduces the voltage across terminals (voltage VH) of capacitor C.

  When the SOC of both power storage devices B1 and B2 reaches the upper limit after the system emergency stop request, ECU 30B activates signal SE output to relay 36 to turn on relay 36. Thereby, electric power that cannot be absorbed by power storage devices B1 and B2 is discharged by discharge resistor 34. Other configurations of ECU 30B are the same as ECU 30A in the second embodiment.

  According to the third embodiment, since the discharge resistor 34 is provided, overvoltage can be prevented even when both SOCs of the power storage devices B1 and B2 reach the upper limit during the emergency stop of the system.

[Embodiment 4]
FIG. 10 is an overall configuration diagram of a hybrid vehicle shown as an example of an electric vehicle equipped with the electric motor drive device according to the fourth embodiment. Referring to FIG. 10, this hybrid vehicle 100 </ b> B further includes an auxiliary device 38 in the configuration of hybrid vehicle 100 shown in FIG. 1, and includes an ECU 30 </ b> C instead of ECU 30.

  Auxiliary machine 38 is connected to positive line PL1 and main negative bus MNL, and is driven based on signal DR from ECU 30C. Auxiliary machine 38 includes, for example, a DC / DC converter that steps down the power supplied from positive line PL1 and outputs the reduced power to the auxiliary power storage device.

  ECU 30C turns on switching element Q11 of first converter 10-1 when the SOCs of power storage devices B1 and B2 reach the upper limit after a system emergency stop request. Then, the ECU 30C generates a signal DR for driving the auxiliary machine 38 and outputs the signal DR to the auxiliary machine 38. Thereby, electric power that cannot be absorbed by power storage devices B1 and B2 flows from capacitor C to auxiliary device 38 via switching element Q11 of first converter 10-1, and is consumed by auxiliary device 38. Other configurations of ECU 30C are the same as ECU 30A in the second embodiment.

  In the above description, auxiliary machine 38 is connected to positive line PL1 and main negative bus MNL. However, auxiliary machine 38 may be connected to positive line PL2 and main negative bus MNL. In this case, ECU 30C turns on switching element Q21 of second converter 10-2 when the SOCs of power storage devices B1 and B2 reach the upper limit after a system emergency stop request.

  According to the fourth embodiment, during an emergency stop of the system, even if both SOCs of power storage devices B1 and B2 reach the upper limit value, overvoltage can be prevented by operating auxiliary machine 38.

[Embodiment 5]
In the fifth embodiment, when the emergency stop of the system is requested, the operation of the power storage devices B1 and B2 with the more SOC is continued.

  FIG. 11 is a diagram showing a flowchart relating to system stop processing by the ECU 30D according to the fifth embodiment. Note that the processing of this flowchart is also executed at regular time intervals or whenever a predetermined condition is satisfied. Referring to FIG. 11, this flowchart further includes steps S12, S60, S70, and S80 in the flowchart shown in FIG.

  That is, when it is determined in step S10 that an emergency stop of the system has been requested (YES in step S10), ECU 30D compares state quantity SOC1 of power storage device B1 with state quantity SOC2 of power storage device B2 (step S12). . If it is determined that state quantity SOC1 is lower than state quantity SOC2 (YES in step S12), ECU 30D moves the process to step S20.

  If it is determined in step S12 that state quantity SOC1 is greater than or equal to state quantity SOC2 (NO in step S12), ECU 30D generates signals SDI1, SDI2, and SDC1, and first inverter 20-1 and second inverter 20- 2 and the first converter 10-1 are stopped (step S60).

  Thereafter, ECU 30D determines whether or not the specified time has elapsed since the emergency stop of the system was requested (step S70), and determines that the specified time has elapsed (YES in step S70), generates signal SDC2. Then, the second converter 10-2 is stopped (step S80).

  According to the fifth embodiment, at the time of an emergency stop of the system, the converter corresponding to the power storage device with a sufficient SOC is operated, so that overvoltage can be reliably prevented.

[Embodiment 6]
In the second embodiment, overvoltage of the voltage VH is prevented by variably setting the upper limit value of the current command of the second converter 10-2 that is current controlled. In the sixth embodiment, the second converter In the control of 10-2, when the current control and the voltage control can be switched and the second converter 10-2 is operated alone after the SOC of the power storage device B1 reaches the upper limit value, the second converter 10- 2 control is switched from current control to voltage control.

  FIG. 12 is a functional block diagram of converter control unit 120B in the sixth embodiment. Referring to FIG. 12, converter control unit 120B includes a signal generation unit 220-2A instead of signal generation unit 220-2 in the configuration of converter control unit 120 shown in FIG. The signal generator 220-2A further includes subtractors 222-3 and 226-3, a proportional-plus-integral controller 224-3, and a changeover switch 232 in the configuration of the signal generator 220-2.

  The subtraction unit 222-3 subtracts the voltage VH from the target value VR set by the setting unit 210, and outputs the calculation result to the proportional integration control unit 224-3. The proportional-plus-integral control unit 224-3 performs a proportional-integral calculation with the deviation between the target value VR and the voltage VH as an input, and outputs the calculation result to the subtracting unit 226-3. The subtraction unit 222-3 and the proportional integration control unit 224-3 constitute a voltage feedback control element.

  Subtraction unit 226-3 subtracts the output of proportional integration control unit 224-3 from the inverse of the theoretical step-up ratio of second converter 10-2 indicated by voltage value VB2 / target value VR, and uses the calculation result as a duty command. Output to the changeover switch 232.

  When receiving the signal STPC1, the changeover switch 232 outputs the duty command received from the subtracting unit 226-3 to the modulating unit 228-2. Therefore, in this case, the second converter 10-2 is voltage-controlled based on the voltage VH. On the other hand, when the changeover switch 232 does not receive the signal STPC1, the changeover switch 232 outputs the duty command received from the subtraction unit 226-2 to the modulation unit 228-2. Therefore, in this case, second converter 10-2 is current-controlled based on current IB2.

  Note that, when the signal generation unit 220-2A receives the signal STPC2, the signal generation unit 220-2A stops generating the signal PWC2.

  As described above, in the sixth embodiment, when state quantity SOC1 of power storage device B1 reaches the upper limit after the system stop request, first converter 10-1 is stopped and second converter 10-2 is operated. Let Second converter 10-2 is normally current-controlled, but is voltage-controlled based on voltage VH when operating after a system stop request. Therefore, according to the sixth embodiment, overvoltage can be prevented even when the SOC of power storage device B1 reaches the upper limit during an emergency stop of the system.

[Embodiment 7]
In the seventh embodiment, if the first converter 10-1 is normal at the time of an emergency stop of the system, the operation of the first converter 10-1 is continued for a specified time, and when the first converter 10-1 is abnormal, The operation of the second converter 10-2 is continued for a specified time.

  FIG. 13 is a flowchart related to the system stop process by the ECU 30E according to the seventh embodiment. Note that the processing of this flowchart is also executed at regular time intervals or whenever a predetermined condition is satisfied. Referring to FIG. 13, this flowchart includes step S14 instead of step S12 in the flowchart shown in FIG.

  That is, when it is determined in step S10 that an emergency stop of the system has been requested (YES in step S10), ECU 30E determines whether or not first converter 10-1 is abnormal (step S14). If it is determined that first converter 10-1 is normal (NO in step S14), ECU 30E proceeds to step S20. On the other hand, when it is determined in step S14 that first converter 10-1 is abnormal (YES in step S14), ECU 30E proceeds to step S60.

  The configuration of the converter control unit in the seventh embodiment is the same as converter converter 120A in the second embodiment shown in FIG. 6 or converter control unit 120B in the sixth embodiment shown in FIG.

  According to the seventh embodiment, even when the first converter 10-1 is abnormal during an emergency stop of the system, overvoltage can be prevented by continuing the operation of the second converter 10-2.

[Embodiment 8]
FIG. 14 is a functional block diagram of converter control unit 120C in the eighth embodiment. Referring to FIG. 14, converter control unit 120 </ b> C includes a setting unit 310, a voltage control unit 320, a distribution unit 330, and current control units 340-1 and 340-2.

  Setting unit 310 sets target value VR of voltage VH. For example, setting unit 310 sets a predetermined voltage higher than voltages VB1 and VB2 as target value VR. In addition, setting section 310 outputs signal SDC1 to first converter 10-1 when receiving signal STPC1, and outputs signal SDC2 to second converter 10-2 when receiving signal STPC2.

  The voltage control unit 320 includes a subtraction unit 322 and a proportional integration control unit 324. The subtraction unit 322 subtracts the voltage VH from the target value VR set by the setting unit 310 and outputs the calculation result to the proportional integration control unit 324. The proportional-integral control unit 324 performs a proportional-integral calculation with the deviation between the target value VR and the voltage VH as an input, and outputs the calculation result to the distribution unit 330 as a current command IR. That is, the current command IR is a current target value for controlling the voltage VH to the target value VR.

  Distribution unit 330 distributes current command IR from voltage control unit 320 to current command IR1 for first converter 10-1 and current command IR2 for second converter 10-2 according to a predetermined distribution ratio. Distribution unit 330 then outputs the distributed current commands IR1 and IR2 to current control units 340-1 and 340-2, respectively.

  Here, when receiving signal STPC1, distribution unit 330 sets the distribution ratio of current command IR2 to 100%, and receives signal STPC2 sets the distribution ratio of current command IR1 to 100%.

  Current control unit 340-1 includes subtraction units 342-1 and 346-1, proportional-integral control unit 344-1, and modulation unit 348-1. Subtraction unit 342-1 subtracts current IB1 from current command IR1, and outputs the calculation result to proportional-integral control unit 344-1. The proportional-plus-integral control unit 344-1 performs a proportional-integral calculation with the deviation between the current command IR1 and the current IB1 as an input, and outputs the calculation result to the subtracting unit 346-1.

  Subtraction unit 346-1 subtracts the output of proportional integration control unit 344-1 from the inverse of the theoretical boost ratio of first converter 10-1 indicated by voltage value VB1 / target value VR, and uses the calculation result as a duty command. It outputs to the modulation part 348-1.

  Modulation section 348-1 generates signal PWC1 based on the duty command received from subtraction section 346-1 and a carrier wave (carrier wave) generated by an oscillation section (not shown), and the generated signal PWC1 is the first. Output to switching elements Q11 and Q12 of converter 10-1.

  When current controller 340-1 receives signal STPC1, current controller 340-1 stops generating signal PWC1.

  Current control unit 340-2 includes subtraction units 342-2 and 346-2, a proportional integration control unit 344-2, and a modulation unit 348-2. Since the configuration of current control unit 340-2 is the same as that of signal generation unit 220-2 shown in FIG. 3, description thereof will not be repeated.

  Note that the current control unit 340-2 also stops generating the signal PWC2 when receiving the signal STPC2.

  In the eighth embodiment, first converter 10-1 and second converter 10-2 are current-controlled by current control unit 340-1 and current control unit 340-2, respectively, but voltage VH is equal to target value VR. Therefore, the voltage VH is controlled to the target value VR even if one converter is operated independently at the time of system emergency stop. Therefore, according to the eighth embodiment, it is possible to prevent overvoltage that may occur at the time of system emergency stop.

[Embodiment 9]
FIG. 15 is a functional block diagram of converter control unit 120D in the ninth embodiment. Referring to FIG. 15, converter control unit 120D includes a setting unit 310, a voltage control unit 320, and signal generation units 350-1 and 350-2. The setting unit 310 and the voltage control unit 320 are as described with reference to FIG.

  Signal generation unit 350-1 includes subtraction unit 346-1 and modulation unit 348-1. Subtraction unit 346-1 subtracts the output of voltage control unit 320 from the inverse of the theoretical boost ratio of first converter 10-1 indicated by voltage value VB1 / target value VR, and uses the calculation result as a duty command to modulation unit 348. Output to -1. The modulation unit 348-1 is as described with reference to FIG. Note that the signal generation unit 350-1 stops generating the signal PWC1 when receiving the signal STPC1.

  Signal generation unit 350-2 includes a subtraction unit 346-2 and a modulation unit 348-2. Subtraction unit 346-2 subtracts the output of voltage control unit 320 from the reciprocal of the theoretical boost ratio of second converter 10-2 indicated by voltage value VB2 / target value VR, and uses calculation result as a duty command to modulation unit 348. Output to -2. The modulation unit 348-2 is as described in FIG. In addition, when the signal generation unit 350-2 receives the signal STPC2 from the stop control unit 110, the signal generation unit 350-2 stops generating the signal PWC2.

  According to the ninth embodiment, even if one of the first converter 10-1 and the second converter 10-2 stops, the voltage VH can be controlled to the target value VR by the other converter, so that the system is urgently Overvoltage can be prevented by operating one converter alone when stopping.

  In each of the above-described embodiments, the so-called series / parallel type hybrid vehicle in which the power of the engine 2 is distributed to the first motor generator MG1 and the drive wheels 6 using the power split mechanism 4 has been described. The present invention is also applicable to a so-called series hybrid vehicle in which the power of the engine 2 is used only for power generation by the first motor generator MG1 and the driving force of the vehicle is generated using only the second motor generator MG2. .

  Further, the present invention can be applied to an electric vehicle that does not include the engine 2 and runs only by electric power, and a fuel cell vehicle that further includes a fuel cell as a power source.

  In the above, first inverter 20-1 and second inverter 20-2 form a “drive circuit” in the present invention, and main positive bus MPL and main negative bus MNL are the “DC power lines” in the present invention. Form. Capacitor C corresponds to “capacitor” in the present invention, and each ECU corresponds to “control device” in the present invention.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

1 is an overall configuration diagram of a hybrid vehicle shown as an example of an electric vehicle equipped with an electric motor drive device according to Embodiment 1 of the present invention. It is a functional block diagram of ECU shown in FIG. It is a detailed functional block diagram of the converter control part shown in FIG. It is the figure which showed the flowchart regarding the system stop process by ECU shown in FIG. FIG. 6 is a functional block diagram of an ECU in a second embodiment. It is a functional block diagram of the converter control part shown in FIG. It is the figure which showed the upper limit setting of the electric current target value by the electric current command limiting part shown in FIG. FIG. 10 is a diagram showing a flowchart regarding system stop processing by an ECU in the second embodiment. FIG. 6 is an overall configuration diagram of a hybrid vehicle shown as an example of an electric vehicle equipped with an electric motor drive device according to a third embodiment. FIG. 10 is an overall configuration diagram of a hybrid vehicle shown as an example of an electric vehicle equipped with an electric motor drive device according to a fourth embodiment. FIG. 10 is a diagram showing a flowchart related to system stop processing by an ECU in the fifth embodiment. FIG. 20 is a functional block diagram of a converter control unit in a sixth embodiment. FIG. 20 is a diagram showing a flowchart regarding system stop processing according to the seventh embodiment. FIG. 20 is a functional block diagram of a converter control unit in an eighth embodiment. FIG. 20 is a functional block diagram of a converter control unit in a ninth embodiment.

Explanation of symbols

  2 engine, 4 power split mechanism, 6 drive wheels, 7, 8 three-phase coil, 10-1 first converter, 10-2 second converter, 20-1 first inverter, 20-2 second inverter, 30, 30A -30C ECU, 32, 42-1, 42-2 Voltage sensor, 34 Discharge resistance, 36 Relay, 38 Auxiliary machine, 44-1, 44-2 Current sensor, 46-1, 46-2 Temperature sensor, 100, 100A , 100B hybrid vehicle, 110, 110A stop control unit, 120, 120A to 120D converter control unit, 130 first inverter control unit, 140 second inverter control unit, 210, 310 setting unit, 220-1, 220-2, 220 -2A, 350-1, 350-2 signal generators, 222-1 to 222-3, 226-1 to 226-3, 322, 3 2-1, 342-2, 346-1, 346-2 subtraction unit, 224-1, 224-2, 324, 344-1, 344-2 proportional integral control unit, 228-1, 228-2, 348- 1, 348-2 modulation unit, 230 current command limiting unit, 232 changeover switch, 320 voltage control unit, 330 distribution unit, 340-1, 340-2 current control unit, MG1 first motor generator, MG2 second motor generator, B1, B2 power storage device, C, C1, C2 capacitor, Q11, Q12, Q21, Q22 switching element, D11, D12, D21, D22 diode, L1, L2 reactor, MPL main positive bus, MNL main negative bus, PL1, PL2 Positive wire.

Claims (11)

An electric motor drive device capable of driving an electric motor,
A drive circuit configured to drive at least one electric motor;
The first power storage device is provided between the rechargeable first power storage device and a DC power line connected to the drive circuit, and is configured to be capable of voltage conversion between the first power storage device and the DC power line. A converter,
A second converter provided between the rechargeable second power storage device and the DC power line, and configured to be capable of voltage conversion between the second power storage device and the DC power line;
A capacitor for smoothing the voltage of the DC power line;
A controller for controlling the first and second converters and the drive circuit;
Each of the first and second converters comprises a direct current chopper circuit including at least one switching element and a reactor capable of storing energy,
The said control apparatus is an electric motor drive device which continues control of either one of the said 1st and 2nd converter after a system stop request | requirement at the time of the system stop of the said electric motor drive device.   The control device estimates a state quantity indicating a charging state of each of the first and second power storage devices, and the state quantity of the power storage device corresponding to the converter to be controlled after the system stop request is an upper limit. The electric motor drive device according to claim 1, wherein when the value is reached, the converter that has been controlled is stopped and the other converter is operated. A discharge resistor provided in parallel with the capacitor;
A relay connected in series with the discharge resistor;
The motor drive device according to claim 2, wherein the control device turns on the relay when the state quantity of each of the first and second power storage devices reaches the upper limit value. An auxiliary machine connected between the first power storage device and the first converter or between the second power storage device and the second converter;
The electric motor drive device according to claim 2, wherein the control device drives the auxiliary machine when the state quantity of each of the first and second power storage devices reaches the upper limit value.   The control device estimates a state quantity indicating a charge state of each of the first and second power storage devices, and after the system stop request, the lower one of the first and second power storage devices. The motor drive device according to claim 1, wherein the control of the converter corresponding to is continued.   The control device controls the voltage of the first converter so that a voltage of the DC power line becomes a target voltage, and controls the second converter so that a charge / discharge current of the second power storage device becomes a target current. The electric motor drive device according to claim 1, wherein current control is performed and control of the first converter is continued after the system stop request.   The control device is configured to be switchable between current control of the second converter or voltage control of the second converter so that the voltage of the DC power line becomes a target voltage, and the system stop request The electric motor drive device according to claim 6, wherein when the first converter is abnormal, the control of the first converter is stopped and the voltage of the second converter is controlled.   The control device generates a current command for controlling the voltage of the DC power line to a target voltage, distributes the current command to the first and second current commands according to a predetermined distribution ratio, and Current control is performed on the first converter so that the charge / discharge current of the power storage device matches the first current command, and the charge / discharge current of the second power storage device matches the second current command. Current control is performed on the second converter, the control of the first converter is continued after the system stop request, and the distribution ratio is set so that the distribution ratio of the first current command becomes 100%. The electric motor drive device according to claim 1. The motor drive device according to any one of claims 1 to 8,
An electric vehicle comprising drive wheels driven by the at least one electric motor. A method for controlling an electric motor driving device capable of driving an electric motor,
The motor driving device is
A drive circuit configured to drive at least one electric motor;
The first power storage device is provided between the rechargeable first power storage device and a DC power line connected to the drive circuit, and is configured to be capable of voltage conversion between the first power storage device and the DC power line. A converter,
A second converter provided between the rechargeable second power storage device and the DC power line, and configured to be capable of voltage conversion between the second power storage device and the DC power line;
A capacitor for smoothing the voltage of the DC power line,
Each of the first and second converters comprises a direct current chopper circuit including at least one switching element and a reactor capable of storing energy,
The control method is:
A first step of determining whether a system stop of the electric motor drive device is requested;
A second step of stopping the drive circuit and stopping one of the first and second converters when it is determined that the system stop is requested;
And a third step of continuing control of the other converter for a specified time after the system stop request. The first converter is voltage-controlled so that the voltage of the DC power line becomes a target voltage,
The second converter is current-controlled so that a charge / discharge current of the second power storage device becomes a target current,
In the second step, the second converter is stopped;
The method for controlling an electric motor drive device according to claim 10, wherein in the third step, the control of the first converter is continued for the specified time after the system stop request.

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