JP2013132181A - Vehicle and control method of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exactly detect the cut-off state of a power converter which drives a rotating electric machine, in a vehicle which can travel by using a drive force generated by the rotating electric machine.SOLUTION: The vehicle 100 can travel by using power from an electric storage device 110 mounted to the vehicle. The vehicle 100 comprises inverters 130, 135 connected to the electric storage device 110 in parallel, motor generators 140, 145 driven by the inverters, respectively, and an ECU 300. The ECU 300 has a determination means based on a current flowing to the inverter 135 in order to determine whether or not the cut-off of the inverter 135 is normally performed when a command for cutting off the inverter 135 is outputted due to the occurrence of an abnormality, and a determination means based on power balance between the electric storage device 110 and the motor generator 140.

Description

  The present invention relates to a vehicle and a vehicle control method, and more particularly to control in an abnormal state in a vehicle that can travel using a driving force generated by a rotating electrical machine.

  2. Description of the Related Art In recent years, attention has been paid to a vehicle that is mounted with a power storage device (for example, a secondary battery or a capacitor) and travels using driving force generated from electric power stored in the power storage device as an environment-friendly vehicle. Such vehicles include, for example, electric vehicles, hybrid vehicles, fuel cell vehicles, and the like.

  In these vehicles, generally, an inverter is used to convert DC power from the power storage device into AC power to drive a rotating electrical machine such as a motor generator. Then, the vehicle is driven using the driving force generated by the rotating electrical machine. When the vehicle is to be stopped, generation of driving force from the rotating electric machine is stopped by setting the inverter in a non-driven state.

  Japanese Patent Laying-Open No. 2010-012827 (Patent Document 1) discloses that in a hybrid vehicle including a generator, an electric motor, and an engine, when the generator is abnormal, the inverter that drives the generator is shut off and the engine is operated independently. A configuration in which a counter electromotive force is generated by a generator, a target voltage of a high voltage system is set to a value corresponding to a counter electromotive voltage that can be generated by the generator, and the motor is driven using the counter electromotive force of the generator Is disclosed.

  By adopting a configuration such as that disclosed in Japanese Patent Application Laid-Open No. 2010-012827 (Patent Document 1), when an abnormality in which the generator cannot be driven normally occurs, the power storage device can be used by using as much of the counter electromotive force of the generator as possible. Can save on power usage. And it becomes possible to continue driving | running | working as long as possible with the drive force of only an electric motor.

JP 2010-012827 A JP 2008-030515 A JP 2001-057705 A JP 2008-259270 A

  In the control disclosed in Japanese Patent Application Laid-Open No. 2010-012827 (Patent Document 1), it is assumed that an inverter for driving the generator is appropriately shut off when an abnormality occurs in the generator. It has become.

  However, when the inverter needs to be shut off as described above, if the inverter is not properly shut off due to an abnormality of the sensor or the control device, unintended power or driving force may be generated. .

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a power conversion device that drives a rotating electrical machine in a vehicle that can travel using a driving force generated by the rotating electrical machine. It is to detect the blocking state with certainty.

  The vehicle according to the present invention is a vehicle capable of traveling using electric power from the installed power storage device. A vehicle includes first and second rotating electrical machines that are electrically coupled in parallel to a power storage device, and first and second rotating electrical machines that are driven by power from the power storage device, respectively. A second power conversion device and a control device for controlling the first and second power conversion devices are provided. The control device determines whether or not the second power conversion device is normally shut off when a command for shutting down the second power conversion device is output due to an abnormality. Determination means based on the current flowing through the power converter and determination means based on the power balance between the power storage device and the first rotating electrical machine.

  Preferably, the control device normally shuts off the second power converter based on a current flowing through the second power converter when the rotation speed of the second rotating electrical machine is lower than a predetermined threshold value. If the rotational speed of the second rotating electrical machine exceeds the threshold value, whether or not the second power converter is normally shut off based on the power balance Determine.

  Preferably, when the rotational speed of the second rotating electrical machine is lower than the threshold value and the current flowing through the second power converter is substantially zero, the control device interrupts the second power converter. It is determined that the operation is normally performed.

  Preferably, when the rotational speed of the second rotating electrical machine is lower than the threshold value and the current flowing through the second power converter is not substantially zero, the control device further includes the second power based on the power balance. It is determined whether or not the conversion device is normally shut off.

  Preferably, the threshold value is the second rotating electrical machine in which the counter electromotive voltage generated by the second rotating electrical machine is larger than the voltage applied to the terminal on the power storage device side of the second power conversion device. It is determined based on the rotation speed.

  Preferably, when the current flowing through the second power conversion device is substantially zero, the control device determines that the second power conversion device is normally shut off and sends the second power conversion device to the second power conversion device. When the flowing current is not substantially zero, it is determined whether or not the second power conversion device is normally shut off based on the power balance.

  Preferably, when the control device determines whether or not the second power conversion device is normally shut off based on the power balance, the magnitude of the input power to the power storage device is the first rotating electrical machine. When the value is larger than the reference value determined from the generated power command, it is determined that the second power conversion device is normally shut off. When the magnitude of the input power to the power storage device is smaller than the reference value, the second It determines with the interruption | blocking of a power converter device not being normally performed.

  Preferably, when it is determined that the second power conversion device is not normally shut off, the control device disconnects the power storage device from the first and second power conversion devices.

  Preferably, the vehicle further includes an engine. The first rotating electrical machine is driven mainly by the engine and operates as a generator. The second rotating electrical machine is coupled to a drive shaft of the vehicle and operates mainly as an electric motor that generates a driving force for traveling the vehicle.

  The vehicle control method according to the present invention is a vehicle control method capable of running using electric power from an installed power storage device. The vehicle includes first and second rotating electrical machines that are electrically coupled in parallel to the power storage device, and a first for driving the first and second rotating electrical machines by electric power from the power storage device, respectively. And a second power conversion device. In the control method, when a command for shutting down the second power converter is output due to an abnormality, the second power converter is normally shut off based on the current flowing through the second power converter. Determining whether or not the second power conversion device is normally shut off based on the power balance between the power storage device and the first rotating electrical machine, and Is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the interruption | blocking state of the power converter device which drives a rotary electric machine can be detected reliably in the vehicle which can drive | work using the driving force generated by the rotary electric machine.

1 is an overall block diagram of a vehicle according to an embodiment. It is a collinear diagram showing the operational relationship of a motor generator and an engine. It is a figure for demonstrating operation | movement when abnormality of a motor generator is detected. In this Embodiment, it is a functional block diagram for demonstrating the monitoring control at the time of the inverter interruption | blocking performed by ECU. In this Embodiment, it is a flowchart for demonstrating the monitoring control process at the time of the inverter interruption | blocking performed by ECU. In the modification of this Embodiment, it is a flowchart for demonstrating the monitoring control process at the time of the inverter interruption | blocking performed by ECU.

  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.

[Basic configuration of vehicle]
FIG. 1 is an overall block diagram of a vehicle 100 according to the present embodiment. Referring to FIG. 1, vehicle 100 includes a power storage device 110, a system main relay (SMR) 115, a converter 120, inverters 130 and 135, motor generators 140 and 145, and a power transmission gear 150. Drive wheel 160, engine 170 which is an internal combustion engine, auxiliary device 180, and ECU (Electronic Control Unit) 300.

  The power storage device 110 is a power storage element configured to be chargeable / dischargeable. The power storage device 110 includes, for example, a secondary battery such as a lithium ion battery, a nickel metal hydride battery, or a lead storage battery, and a power storage element such as an electric double layer capacitor.

  Power storage device 110 is connected to converter 120 through power lines PL1, NL1. Power storage device 110 supplies electric power for driving motor generators 140 and 145 to converter 120. Power storage device 110 stores the electric power generated by motor generators 140 and 145. The output of power storage device 110 is, for example, about 200V.

  SMR 115 includes a relay connected between a positive electrode terminal of power storage device 110 and power line PL1, and a relay connected between a negative electrode terminal of power storage device and power line NL1. SMR 115 is controlled by control signal SE <b> 1 from ECU 300, and switches between power supply and cutoff between power storage device 110 and converter 120.

  Capacitor C1 is connected between power line PL1 and power line NL1. Capacitor C1 reduces voltage fluctuation between power line PL1 and power line NL1. Voltage sensor 117 detects the voltage applied to capacitor C1 and outputs the detected value VL to ECU 300.

  Converter 120 includes switching elements Q1, Q2, diodes D1, D2, and a reactor L1.

  Switching elements Q1 and Q2 are connected in series between power lines PL2 and NL1, with the direction from power line PL2 toward power line NL1 as the forward direction. In this embodiment, an IGBT (Insulated Gate Bipolar Transistor) is described as an example of the switching element, but a power MOS (Metal Oxide Semiconductor) transistor or a power bipolar transistor is used instead of the IGBT. Also good.

  Antiparallel diodes D1 and D2 are connected to switching elements Q1 and Q2, respectively. Reactor L1 is provided between a connection node of switching elements Q1, Q2 and power line PL1. That is, converter 120 forms a chopper circuit.

  Switching elements Q1, Q2 are controlled based on control signal PWC from ECU 300, and perform voltage conversion operation between power lines PL1, NL1 and power lines PL2, NL1.

  Converter 120 is basically controlled such that switching elements Q1 and Q2 are turned on and off in a complementary manner in each switching period. Converter 120 boosts the DC voltage from power storage device 110 during the boosting operation. This boosting operation is performed by supplying the electromagnetic energy accumulated in reactor L1 during the ON period of switching element Q2 to power line PL2 via switching element Q1 and antiparallel diode D1.

  Converter 120 steps down the DC voltage from inverter 130 during the step-down operation. This step-down operation is performed by supplying the electromagnetic energy stored in reactor L1 during the ON period of switching element Q1 to power line NL1 via switching element Q2 and antiparallel diode D2.

  The voltage conversion ratio in these step-up and step-down operations is controlled by the on-period ratio (duty ratio) of the switching elements Q1 and Q2 in the switching period. When the step-up operation and the step-down operation are not required, the voltage conversion ratio = 1.0 (duty ratio = 100) is set by setting the control signal PWC to fix the switching elements Q1 and Q2 to ON and OFF, respectively. %).

  In the present invention, converter 120 is not essential, and the output voltage from power storage device 110 may be directly supplied to inverter 130.

  Capacitor C2 is connected between power lines PL2 and NL1 connecting converter 120 and inverters 130 and 135. Capacitor C2 reduces voltage fluctuation between power lines PL2 and NL1. Voltage sensor 125 detects the voltage applied to capacitor C2 and outputs the detected value VH to ECU 300.

  Inverters 130 and 135 are connected to converter 120 in parallel via power lines PL2 and NL1. Inverter 130 is controlled by control command PWI <b> 1 from ECU 300 and converts the DC power output from converter 120 into AC power for driving motor generator 140. Inverter 135 is controlled by control command PWI <b> 2 from ECU 300, and converts the DC power output from converter 120 into AC power for driving motor generator 145.

  Note that the detailed configuration inside the inverter described below will be described by taking an inverter 135 for driving the motor generator 145 as an example. Although the internal configuration of inverter 130 is not shown in FIG. 1, it is basically the same as inverter 135 and will not be described repeatedly.

  Inverter 135 includes a U-phase arm 136, a V-phase arm 137, and a W-phase arm 138, which form a three-phase bridge circuit. U-phase arm 136, V-phase arm 137, and W-phase arm 138 are connected in parallel between power line PL2 and power line NL1.

  U-phase arm 136 includes switching elements Q3 and Q4 connected in series between power line PL2 and power line NL1, and diodes D3 and D4 connected in parallel to switching elements Q3 and Q4, respectively. The cathode of diode D3 is connected to the collector of switching element Q3, and the anode of diode D3 is connected to the emitter of switching element Q3. The cathode of diode D4 is connected to the collector of switching element Q4, and the anode of diode D4 is connected to the emitter of switching element Q4.

  V-phase arm 137 includes switching elements Q5 and Q6 connected in series between power line PL2 and power line NL1, and diodes D5 and D6 connected in parallel to switching elements Q5 and Q6, respectively. The cathode of diode D5 is connected to the collector of switching element Q5, and the anode of diode D5 is connected to the emitter of switching element Q5. The cathode of diode D6 is connected to the collector of switching element Q6, and the anode of diode D6 is connected to the emitter of switching element Q6.

  W-phase arm 138 includes switching elements Q7 and Q8 connected in series between power line PL2 and power line NL1, and diodes D7 and D8 connected in parallel to switching elements Q7 and Q8, respectively. The cathode of diode D7 is connected to the collector of switching element Q7, and the anode of diode D7 is connected to the emitter of switching element Q7. The cathode of diode D8 is connected to the collector of switching element Q8, and the anode of diode D8 is connected to the emitter of switching element Q8.

  Motor generator 145 is, for example, a three-phase AC motor generator including a rotor in which permanent magnets are embedded and a stator having a three-phase coil Y-connected at a neutral point. Three ends of U-phase, V-phase, and W-phase (not shown) are each connected together at one end to a neutral point, and the other end of the U-phase coil is connected to a connection node of switching elements Q3 and Q4. The other end of the V-phase coil is connected to a connection node of switching elements Q5 and Q6, and the other end of the W-phase coil is connected to a connection node of switching elements Q7 and Q8.

  When the inverter is shut off, all the gates of switching elements Q3 to Q8 are turned off to be in a non-conductive state.

  The output torque of motor generators 140 and 145 is transmitted to drive wheels 160 via power transmission gear 150 constituted by a speed reducer and a power split mechanism, and causes vehicle 100 to travel. Motor generators 140 and 145 can generate electric power by the rotational force of drive wheels 160 during regenerative braking operation of vehicle 100. Then, the generated power is converted into charging power for power storage device 110 by inverter 135.

  Engine 170 is coupled to motor generators 140 and 145 through power transmission gear 150. ECU 300 generates necessary vehicle driving force by operating engine 170 and motor generators 140 and 145 cooperatively. In this case, it is also possible to charge power storage device 110 using the electric power generated by the motor generator using the rotation of engine 170.

  In the present embodiment, motor generator 145 (also referred to as MG2) is exclusively used as an electric motor for driving drive wheels 160, and motor generator 140 (also referred to as MG1) is exclusively used for power generation driven by engine 170. The case where it is used as a machine will be described as an example.

  The power transmission gear 150 includes a planetary gear mechanism (not shown). An output shaft of motor generator 140 is coupled to the sun gear (S) of the planetary gear, an output shaft of engine 170 is coupled to the carrier (C), and an output shaft of motor generator 145 is coupled to the ring gear (R). The output shaft of motor generator 145 is coupled to drive wheel 160 via a speed reducer (not shown). In addition, such a coupling | bonding aspect is an example and the other coupling | bonding aspect may be sufficient.

  Current sensor 190 is provided in a power transmission path between inverter 130 and motor generator 140, detects a current flowing through motor generator 140, and outputs a detected value MCRT1 to ECU 300. Current sensor 195 is provided in a power transmission path between inverter 135 and motor generator 145, detects a current flowing through motor generator 145, and outputs a detected value MCRT2 to ECU 300.

  Since the sum of the currents flowing in the respective phases of motor generators 140 and 145 is always zero, it is sufficient that current sensors 190 and 195 are provided in at least one of the two phases of the power transmission path. The current sensor is provided, for example, in a U-phase and V-phase power transmission path between the inverter and the motor generator.

  The rotation angle sensors 200 and 205 are provided in the motor generators 140 and 145, respectively. Rotation angle sensors 200 and 205 detect rotation angles θ1 and θ2 of motor generators 140 and 145, respectively, and output detected values to ECU 300. ECU 300 calculates the rotation speed or angular velocity of motor generators 140 and 145 based on rotation angles θ1 and θ2 from rotation angle sensors 200 and 205.

  Auxiliary device 180 is connected in parallel to inverters 130 and 135 to power lines PL2 and NL1. Although not shown in the drawings, the auxiliary device 180 is used to convert the voltage into a voltage suitable for an air conditioner for air-conditioning the interior of the vehicle, a low-voltage system (for example, 12V), and these low-voltage systems. A DC / DC converter or the like is included.

  ECU 300 includes a CPU (Central Processing Unit), a storage device, and an input / output buffer, all of which are not shown in FIG. 1, and inputs signals from each sensor and the like, and outputs control signals to each device. 100 and each device are controlled. Control in ECU 300 is not limited to processing by software, and processing by dedicated hardware (electronic circuit) is also possible.

  In addition, in FIG. 1, although demonstrated as an example the structure provided with one ECU300 as a control apparatus, the structure of a control apparatus is not limited to this. For example, ECU 300 may have a configuration in which a control device is provided for each device or function.

  ECU 300 receives voltage VB and current IB from power storage device 110. ECU 300 calculates a state of charge (SOC) of the power storage device based on voltage VB and current IB. ECU 300 receives engine rotation speed Ne from a sensor included in engine 170 and failure signals FLT 1 and FLT 2 from inverters 130 and 135.

  In a vehicle having such a configuration, motor generator 140 (MG1), motor generator 145 (MG2), and engine 170 generally operate in accordance with a nomograph as shown in FIG. In FIG. 2, the rotation speeds of the planetary gear sun gear (S), carrier (C) and ring gear (R), that is, the rotation speeds Nm1, Ne, and Nm2 of MG1, engine 170, and MG2, are shown on the vertical axis.

  For example, in the state where the vehicle is traveling as shown in FIG. 2, positive torques Te and Tm2 are output from the engine 170 and MG2, so that each device has a predetermined rotational speed with these torques. Negative torque Tm1 is added to MG1. In this case, since MG1 has a positive rotation and a negative torque, a power generation operation is performed. The generated power in MG1 is used as power for driving MG2 and / or power for charging power storage device 110.

  In such a state, for example, there is some abnormality in the system that drives the motor generator, such as a failure of a switching element in the inverter, a break in the coil of the motor generator, or an abnormality in a detector such as a current sensor or a rotation angle sensor. When this occurs, generally, the inverter is shut off and the vehicle is evacuated to protect the equipment and prevent the vehicle from operating abnormally.

  For example, as shown in FIG. 3, when an abnormality occurs in the MG2 system and the inverter 135 is shut off, the output torque Tm2 from the MG2 becomes zero. Accordingly, the torque of MG1 is reduced to Tm1 # so that the nomographic relationship is maintained. The generated power generated by MG1 at this time is basically used for charging the power storage device, but a part is consumed by the resistance component of the auxiliary device and the power transmission path.

  However, when the inverter cannot be properly shut off in such a state, there is a possibility that a failure of the device is promoted or a torque unintended by the user is generated. Therefore, when the inverter is shut down due to an abnormality, it is necessary to monitor that the inverter is reliably shut off and no unintended torque is generated.

  In order to monitor the interruption of the inverter, there is a method of monitoring the current flowing from the inverter to the motor generator, or a method of monitoring using the power balance between the power supplied from the power storage device or MG1 and the power consumed by other devices. Can be adopted.

  However, even if the inverter is shut off normally, if the motor generator is rotating at high speed, the current flows through the diode in the inverter due to the counter electromotive force generated by the motor generator. There may be a case where it is not possible to recognize the interruption.

  On the other hand, in the monitoring based on the power balance, there may be a case where the judgment cannot be made correctly in the region of relatively low rotation due to the influence of unclear elements of the power consumption due to the auxiliary machine and the power transmission path.

  Therefore, in this embodiment, when an abnormality occurs in the drive system of the motor generator, the monitoring by the current and the monitoring by the power balance are selectively switched as appropriate according to the traveling state of the vehicle, and the inverter is shut off. And a method of appropriately monitoring the generation of unintended torque is adopted.

  FIG. 4 is a functional block diagram for illustrating the monitoring control when the inverter is shut off, which is executed by ECU 300 in the present embodiment. Each functional block described in the functional block diagram illustrated in FIG. 4 is realized by hardware or software processing by ECU 300.

  Referring to FIGS. 1 and 4, ECU 300 includes an abnormality detection unit 310, a determination unit 320, an inverter (INV) control unit 330, and a relay control unit 340.

  Abnormality detection unit 310 receives failure signals FLT1, FLT2 from inverters 130, 135 and detection values MCRT1, MCRT2 from current sensors 190, 195. Abnormality detection unit 310 determines whether or not an abnormality has occurred in inverters 130 and 135 and / or motor generators 140 and 145 based on these pieces of information. Then, abnormality detection unit 310 generates control signal SDN for shutting down the inverter on which the abnormality has occurred, and outputs the control signal SDN to determination unit 320 and INV control unit 330.

  In addition to the control signal SDN from the abnormality detection unit 310, the determination unit 320 detects the current detection values MCRT1 and MCRT2 from the current sensors 190 and 195, the current IB and voltage VB from the power storage device 110, and the rotation angle sensors 200 and 205. , Rotation speeds Nm1 and Nm2 based on the rotation angles θ1 and θ2, and command torques TR1 and TR2 to motor generators 140 and 145 from a host ECU (not shown) and power PAUX consumed by auxiliary device 180. Based on these pieces of information, the determination unit 320 determines whether or not the inverter to be interrupted is appropriately interrupted by a method described later with reference to FIG. 5 or FIG. Then, the determination flag FLG is output to the INV control unit 330 and the relay control unit 340.

  INV control unit 330 receives control signal SDN from abnormality detection unit 310 and determination flag FLG from determination unit 320. Further, INV control unit 330 receives command torques TR1, TR2 and rotational speeds Nm1, Nm2 of motor generators 140, 145.

  The INV control unit 330 basically generates control signals PWI1 and PWI2 for the inverters 130 and 135 based on the command torques TR1 and TR2 and the rotational speeds Nm1 and Nm2, and drives the inverters 130 and 135 using them. To do.

  INV control unit 330 generates control signal PWI so that the switching element included in the corresponding inverter is gate-cut when inverter cut-off is instructed by control signal SDN from abnormality detection unit 310. Further, the INV control unit 330 stops both the inverters 130 and 135 when the determination flag FLG from the determination unit 320 indicates that the inverter to be blocked is not properly blocked. Control signals PWI1 and PWI2 are generated.

  Relay control unit 340 receives determination flag FLG from determination unit 320. When the determination flag FLG indicates that the inverter to be shut off is not properly shut off, the relay control unit 340 generates a control signal SE1 that turns off the SMR 115, and the system stop state ( Ready off state).

  FIG. 5 is a flowchart for illustrating the monitoring control process when the inverter is shut off, which is executed by ECU 300 in the present embodiment. In the flowchart shown in FIG. 5 and FIG. 6 described below, the processing is realized by a program stored in advance in the ECU 300 being called from the main routine and executed in a predetermined cycle. Alternatively, for some steps, it is also possible to construct dedicated hardware (electronic circuit) and realize processing. In the following flowchart, a case where an abnormality occurs in inverter 135 (also referred to as INV2) or motor generator 145 (MG2) for driving drive wheel 160 will be described as an example, but inverter 130 and motor generator 145 are also described. The same applies to the case where an abnormality occurs.

  Referring to FIGS. 1 and 5, ECU 300 determines in step (hereinafter abbreviated as S) 100 whether inverter 135 and / or motor generator 145 has an abnormality.

  When there is no abnormality in inverter 135 and / or motor generator 145, that is, when it is normal (NO in S100), ECU 300 skips the subsequent processes and ends the process because the control is not necessary.

  If abnormality has occurred in inverter 135 and / or motor generator 145 (YES in S100), the process proceeds to S110, and ECU 300 generates control signal PWI2 that shuts down (shuts down) inverter 135, and Output to inverter 135.

  Thereafter, in S120, ECU 300 determines whether or not the current flowing through motor generator 145 is substantially zero (MCRT2 = 0) based on detection value MCRT2 of current sensor 195.

  If MCRT2 is substantially zero (YES in S120), the process proceeds to S130, and ECU 300 determines that inverter 135 is normally shut off. Thereafter, the process proceeds to S140, and ECU 300 continues the retreat travel in a state where inverter 135 is shut off, assuming normal operation.

  If MCRT2 is not substantially zero in S120 (NO in S120), the process proceeds to S150, and ECU 300 then inputs / outputs power (also referred to as battery power) obtained from voltage VB and current IB of power storage device 110. )) And the value obtained by subtracting the power consumption PAUX of the auxiliary device 180 from the power command value of the motor generator 140 (MG1). It is assumed that the power input to power storage device 110 and the generated power from motor generator 140 are positive.

  If the battery power is greater than or equal to the difference between MG1 power command value and auxiliary power PAUX (YES in S150), the process proceeds to S160, and ECU 300 causes motor generator 145 (MG2) to rotate by drive wheels 160. Therefore, it is determined that the back electromotive voltage of motor generator 145 generated is higher than VH, and current is flowing from motor generator 145 into power storage device 110 due to the back electromotive force generated in motor generator 145.

  For example, when the vehicle speed is high, the back electromotive force generated by the motor generator 145 becomes large even when the inverter 130 is in the cut-off state, so that such a state can occur. That is, even if a current flows through motor generator 145, in this case, inverter 130 is properly cut off.

Therefore, ECU 300 advances the process to S140 and continues the retreat travel.
On the other hand, when the battery power is smaller than the difference between MG1 power command value and auxiliary power PAUX (NO in S150), the process proceeds to S170, and ECU 300 stores the power input to power storage device 110. It is determined that there is a high possibility that an electric power is consumed by motor generator 145 and an unintended driving force is generated. In other words, ECU 300 determines that inverter 135 is not normally shut off.

  In S180, ECU 300 shuts off inverter 130, opens SMR 115, and enters the Ready-off state. ECU 300 then disconnects inverters 130 and 135 from power storage device 110.

  By controlling according to the above processing, when the inverter is shut down due to an abnormality, it is determined whether the inverter is shut off properly in consideration of the influence of the back electromotive force generated by the motor generator. Is possible.

[Modification]
As described above, the current flows into the power storage device due to the back electromotive force of the motor generator when the rotation speed of the motor generator is high and the back electromotive force of the motor generator exceeds the terminal voltage VH on the power storage device side of the inverter. It is.

  Therefore, in a modified example, a configuration will be described in which a determination is further made as to whether or not the rotation speed is higher as the rotation speed of the motor generator exceeds VH. In the case of high rotation, even a slight torque fluctuation (that is, current fluctuation) causes a large electric power fluctuation to be generated. For this reason, it is first determined whether or not the motor generator is high-speed, and thereby switching whether or not to determine whether or not to cut off using the power balance, thereby increasing the sensitivity to detect the generation of unintended driving force. Can do.

  FIG. 6 is a flowchart for illustrating a monitoring control process when the inverter is shut off, which is executed by ECU 300, in the modification of the present embodiment. FIG. 6 is obtained by adding step S115 to the flowchart described in FIG. In FIG. 6, the description of the same steps as those in FIG. 5 will not be repeated.

  Referring to FIGS. 1 and 6, if an abnormality has occurred in inverter 135 and / or motor generator 145 (YES in S100) and a shutoff command for inverter 135 is output (S110), the process proceeds to S115. ECU 300 determines whether or not rotational speed Nm2 of motor generator 145 is greater than threshold value α.

  This threshold value α is determined based on the rotation speed when the back electromotive voltage of motor generator 145 is greater than VH. The threshold value α may be a fixed value in consideration of the fluctuation range of VH, or may be a variable value set corresponding to the changing VH.

  If rotational speed Nm2 of motor generator 145 is greater than threshold value α (YES in S115), the process proceeds to S150, and ECU 300 is based on the power balance regardless of detection value MCRT2 from current sensor 195. It is determined whether or not the inverter 135 is normally shut off.

  On the other hand, when rotation speed Nm2 of motor generator 145 is equal to or lower than threshold value α (NO in S115), the process proceeds to S120, and ECU 300 first normally disconnects inverter 135 based on current value MCRT2. (YES in S120, S130), and if current value MCRT2 is not substantially zero (NO in S120), it is determined whether inverter 135 is normally shut off based on the power balance. (S150).

  By controlling according to the above processing, when the inverter is shut down due to an abnormality, it is determined whether the inverter is shut off properly in consideration of the influence of the back electromotive force generated by the motor generator. Is possible.

  Although not shown in FIG. 6, when current value MCRT2 is not substantially zero in step S120 (NO in S120), it may be determined as abnormal and the process may proceed to step S170.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  100 vehicle, 110 power storage device, 115 SMR, 117, 125 voltage sensor, 120 converter, 130, 135 inverter, 136 U-phase arm, 137 V-phase arm, 138 W-phase arm, 140, 145 motor generator, 150 power transmission gear, 160 Drive Wheel, 170 Engine, 180 Auxiliary Equipment, 190, 195 Current Sensor, 200, 205 Rotation Angle Sensor, 300 ECU, 310 Abnormality Detection Unit, 320 Determination Unit, 330 INV Control Unit, 340 Relay Control Unit, C1, C2 Capacitor, D1-D8 diode, L1 reactor, NL1, PL1, PL2 power line, Q1-Q8 switching element.

Claims (10)

A vehicle capable of traveling using electric power from an installed power storage device,
First and second rotating electrical machines electrically coupled in parallel to the power storage device;
First and second power converters for driving the first and second rotating electric machines, respectively, with electric power from the power storage device;
A control device for controlling the first and second power converters,
The control device is configured to determine whether or not the second power conversion device is normally shut off when a command for shutting down the second power conversion device is output due to an abnormality. A vehicle comprising: determination means based on a current flowing through the second power conversion device; and determination means based on a power balance between the power storage device and the first rotating electrical machine.   When the rotational speed of the second rotating electrical machine is lower than a predetermined threshold value, the control device shuts off the second power conversion device based on a current flowing through the second power conversion device. It is determined whether or not it is normally performed, and when the rotation speed of the second rotating electrical machine exceeds the threshold value, the second power conversion device is normally shut off based on the power balance. The vehicle according to claim 1, wherein it is determined whether or not the vehicle is broken.   When the rotational speed of the second rotating electrical machine is lower than the threshold value and the current flowing through the second power converter is substantially zero, the control device is configured to control the second power converter. The vehicle according to claim 2, wherein the vehicle is determined to be shut off normally.   When the rotational speed of the second rotating electrical machine is lower than the threshold value and the current flowing through the second power conversion device is not substantially zero, the control device further includes the first power based on the power balance. The vehicle according to claim 3, wherein it is determined whether or not the power conversion device 2 is normally shut off.   The threshold value is set so that a counter electromotive voltage generated by the second rotating electrical machine is larger than a voltage applied to a terminal on the power storage device side of the second power conversion device. The vehicle according to claim 2, wherein the vehicle is determined based on a rotation speed of the rotating electrical machine.   When the current flowing through the second power conversion device is substantially zero, the control device determines that the second power conversion device is normally shut off, and the second power conversion device 2. The vehicle according to claim 1, wherein when the current flowing through the second power converter is not substantially zero, it is determined whether or not the second power conversion device is normally shut off based on the power balance.   When determining whether or not the second power conversion device is normally shut off based on the power balance, the control device determines that the magnitude of input power to the power storage device is the first power When larger than the reference value determined from the generated power command of the rotating electrical machine, it is determined that the second power conversion device is normally shut off, and the magnitude of the input power to the power storage device is larger than the reference value. The vehicle according to any one of claims 1 to 6, wherein when it is small, it is determined that the second power conversion device is not normally shut off.   8. The control device according to claim 7, wherein the control device disconnects the power storage device from the first and second power conversion devices when it is determined that the second power conversion device is not normally shut off. 9. Vehicle. An engine,
The first rotating electrical machine is driven mainly by the engine and operates as a generator,
The vehicle according to claim 1, wherein the second rotating electrical machine is coupled to a drive shaft of the vehicle and operates as an electric motor that mainly generates a driving force for traveling the vehicle. A method for controlling a vehicle capable of traveling using electric power from an installed power storage device,
The vehicle is
First and second rotating electrical machines electrically coupled in parallel to the power storage device;
Including first and second power converters for driving the first and second rotating electric machines, respectively, with electric power from the power storage device,
In the case where a command for shutting down the second power conversion device is output due to an abnormality, the control method is
Determining whether or not the second power conversion device is normally shut off based on a current flowing through the second power conversion device;
Determining whether or not the second power conversion device is normally shut off based on a power balance between the power storage device and the first rotating electrical machine. .

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