JP2018068035A - Electric car - Google Patents

Abstract

The present specification provides a technique for improving the safety of a traveling motor while power is being transmitted between a high voltage battery and a device outside the vehicle. A hybrid vehicle includes a power converter and an HV controller. The power converter 10 receives power supply from the power transistor 16a and the like through which the power of the high voltage battery 2 flows, a transistor drive circuit 50 that generates a drive signal to be supplied to the gate of the power transistor 16a and the like, and the auxiliary battery 95. A power supply circuit 51 that generates power for the transistor drive circuit, a load switch 42 that switches connection and disconnection between the auxiliary battery 95 and the power supply circuit 51, and various sensors are provided. The motor controller 30 and the HV controller 4 use the power converter 10 based on the measurement values of various sensors while the load switch 42 is opened while power is being transmitted between the high voltage battery 2 and an external device. Check whether an abnormality has occurred. [Selection] Figure 2

Description

  The present specification discloses an electric vehicle capable of transmitting power between a high-voltage battery that stores electric power for driving a motor for traveling and a device outside the vehicle. The “electric vehicle” in this specification includes a hybrid vehicle including a motor and an engine for traveling.

  The above-described electric vehicle is disclosed in Patent Document 1, for example. An electric vehicle includes a power converter that converts DC power of a high-voltage battery into driving power for a motor. In the electric vehicle of Patent Document 1, the power converter and the motor are disconnected from the high voltage battery while the main switch (ignition switch) of the vehicle is off. Therefore, a relay (system main relay) is provided between the high voltage battery and the power converter. Is provided.

JP 2011-087445 A

  In the electric vehicle of Patent Document 1, a socket into which a power cable for transmitting power between a high voltage battery and a device outside the vehicle is inserted is connected to the power converter side of the system main relay. Therefore, it is necessary to close the system main relay in order to transfer power between the high-voltage battery and a device outside the vehicle. When the system main relay is closed, the high voltage battery is electrically connected to the power converter and the motor. The present specification provides a technique for improving the safety of a traveling motor while power is being transmitted between a high-voltage battery and a device outside the vehicle.

  The electric vehicle disclosed in this specification includes a high voltage battery, an auxiliary battery, a system main relay, a power converter, a socket, and a controller. The high voltage battery stores electric power for driving the motor for traveling. The auxiliary battery is a power source for supplying power to a group of devices that operate at a voltage lower than the output voltage of the high voltage battery. The power converter is connected between the high voltage battery and the motor, and is a device that converts the power of the high voltage battery into the driving power of the motor. The system main relay is connected between the high voltage battery and the power converter. The socket is an insertion port for inserting a power cable for transmitting power between the high-voltage battery and a device outside the vehicle, and is connected to the power converter side of the system main relay.

  The power converter includes a power transistor, a transistor drive circuit, a power supply circuit, a power supply circuit switch, and a sensor. The power transistor is a main component that converts the power of the high-voltage battery into the driving power of the motor for traveling. The transistor drive circuit generates a drive signal to be supplied to the gate of the power transistor. The power supply circuit receives power supply from the auxiliary battery and generates power for the transistor drive circuit. The power circuit switch switches connection and disconnection between the auxiliary battery and the power circuit. The sensor measures the current or voltage of the power line through which the high-voltage battery power flows. The transistor drive circuit includes a pull-down resistor connected between the signal line connected to the gate of the power transistor and the ground. Then, the controller converts the power converter based on the measured value of the sensor with the power supply circuit switch opened while the system main relay is closed and power is transmitted between the high voltage battery and the device outside the vehicle. Check if there is an abnormality in.

  The electric vehicle disclosed in this specification is connected to a gate as well as interrupting power supply to a power supply circuit for a transistor driving circuit while transmitting power between a main battery and an external device. A pull-down resistor is provided to ensure that the signal line is held at the LOW level. In addition, the power converter is checked to see if an abnormality has occurred in the power converter during power transmission while the power supply to the power supply circuit for the transistor drive circuit is cut off. Is higher. Details and further improvements of the technology disclosed in this specification will be described in the following “DETAILED DESCRIPTION”.

It is a block diagram of the electric power system of the electric vehicle of an Example. It is a block diagram which shows the circuit structure of a motor controller. It is a flowchart figure when performing electric power transmission between the apparatuses outside a vehicle. FIG. 4 is a flowchart when power transmission is performed with a device outside the vehicle (continuation of FIG. 3). It is a flowchart figure of a transistor drive circuit check process. FIG. 5 is a flowchart when power transmission is performed with a device outside the vehicle (continuation of FIG. 4).

  An electric vehicle according to an embodiment will be described with reference to the drawings. The electric vehicle according to the embodiment is a hybrid vehicle 100 including a motor and an engine for traveling. FIG. 1 shows a block diagram of a power system of hybrid vehicle 100. In FIG. 1, a solid line indicates a power line, and a dotted line indicates a signal line. The hybrid vehicle 100 travels with a motor 91 and an engine 92. The output shaft of the motor 91 and the output shaft of the engine 92 are combined by the gear set 93 and transmitted to the axle 94.

  The hybrid vehicle 100 includes a high voltage battery 2 and an auxiliary battery 95 as power sources. The high voltage battery 2 stores electric power for driving the motor 91. The hybrid vehicle 100 includes various devices that are driven at a voltage lower than the output voltage of the high-voltage battery 2, and the auxiliary battery 95 is provided to supply power to these devices. Various devices that are driven at a voltage lower than the output voltage of the high-voltage battery 2 are collectively referred to as “auxiliary machines”. Although not shown in FIG. 1, the hybrid vehicle 100 includes a step-down converter that steps down the voltage of the high voltage battery 2 and charges the auxiliary battery 95.

  The power converter 10 is connected between the high voltage battery 2 and the traveling motor 91. The power converter 10 is a device that converts DC power of the high-voltage battery 2 into drive power for the motor 91. The motor 91 is a three-phase AC motor. Specifically, the power converter 10 is a voltage converter 11 that boosts the voltage of the high-voltage battery 2 and the boosted DC power is converted into a three-phase AC for driving the motor. An inverter 20 for converting to electric power is provided. When the driver steps on the brake, the motor 91 generates power using the kinetic energy of the vehicle. AC power (regenerative power) obtained by power generation is converted into DC power by the inverter 20 and further stepped down by the voltage converter 11. The high voltage battery 2 is charged with the electric power obtained by the power generation of the motor 91. The voltage converter 11 is a bidirectional DC-DC converter having a step-up function for stepping up the output voltage of the high-voltage battery 2 and a step-down function for stepping down the voltage of regenerative power sent from the inverter 20.

  The configuration of the voltage converter 11 will be described. The voltage converter 11 includes two power transistors 16a and 16b, two diodes 17a and 17b, a reactor 15, and a filter capacitor 12. The two power transistors 16a and 16b are connected in series. The series connection of the power transistors 16 a and 16 b is connected between the positive electrode 11 c and the negative electrode 11 d at the high voltage end of the voltage converter 11. A diode 17a is connected in antiparallel to the power transistor 16a, and a diode 17b is connected in antiparallel to the power transistor 16b. One end of the reactor 15 is connected to the midpoint of the series connection of the two power transistors 16a and 16b. The other end of the reactor 15 is connected to the positive electrode 11 a at the low voltage end of the voltage converter 11. The filter capacitor 12 is connected between the positive electrode 11 a and the negative electrode 11 b at the low voltage end of the voltage converter 11.

  The step-down operation is realized by turning on / off the power transistor 16a, and the step-up operation is realized by turning on / off the power transistor 16b. The power transistors 16 a and 16 b are controlled by the motor controller 30. The motor controller 30 sends complementary PWM signals to the gates of the power transistors 16a and 16b. With the complementary PWM signal, the voltage converter 11 operates so that the ratio of the low-voltage side voltage to the high-voltage side voltage maintains the target ratio. If the voltage on the high voltage side increases due to regenerative power, power flows from the high voltage side to the low voltage side, otherwise power flows from the low voltage side to the high voltage side. The voltage converter 11 is a hybrid vehicle (electric vehicle) in which power running (driving the motor 91 with the power of the high-voltage battery 2) and regeneration (power generation by the motor 91) are frequently switched by the driver's accelerator work and brake work. ) Is a suitable circuit.

  The voltage converter 11 includes a voltage sensor 13 that measures the voltage on the low voltage side, and a current sensor 14 that measures the current flowing through the reactor. A voltage sensor 19 is also provided between the positive electrode 11 c and the negative electrode 11 d on the high voltage side of the voltage converter 11. The motor controller 30 generates drive signals for the two power transistors 16a and 16b based on the measured values of the voltage sensors 13 and 19 and the current sensor 14, and supplies them to the gates of the power transistors 16a and 16b.

  The inverter 20 has a circuit configuration in which three sets of series connection of two power transistors are connected in parallel. An alternating current is output from the midpoint of each series connection, and a three-phase alternating current is generated by three sets of serial connections. Since the circuit configuration of the inverter 20 is well known, the illustration is omitted. Each power transistor of the inverter 20 is also controlled by the motor controller 30. A current sensor 21 is attached to each of the three-phase AC output lines of the inverter 20. The motor controller 30 receives a command of the target output of the motor 91 from the HV controller 4 that controls the entire hybrid vehicle 100, and based on the measured values of various sensors, The power transistor of the inverter 20 is controlled. Between the voltage converter 11 and the inverter 20, a smoothing capacitor 18 that suppresses pulsation of a current flowing between them is connected in parallel.

  The HV controller 4 calculates the target output of the motor 91 and the target output of the engine 92 based on information such as the opening degree of the accelerator pedal, the depression amount of the brake pedal, the vehicle speed, and the remaining amount of the high-voltage battery 2. The HV controller 4 sends the target output of the motor 91 to the motor controller 30 and sends the target output of the engine 92 to an engine controller (not shown).

  The motor controller 30 and the HV controller 4 belong to an auxiliary machine and operate by receiving power supply from the auxiliary battery 95. The motor controller 30 is connected to an auxiliary battery 95 via an ignition relay 96. Note that the negative electrode of the auxiliary battery 95 is connected to the body ground Gb. The body ground Gb is a ground common to all auxiliary machines. The HV controller 4 is directly connected to the auxiliary battery 95. When the main switch of the vehicle is turned on, the ignition relay 96 is closed and the motor controller 30 and other auxiliary machines are connected to the auxiliary battery 95. A system main relay 3 is connected between the high voltage battery 2 and the power converter 10, and when the main switch of the vehicle is turned on, the HV controller 4 closes the system main relay 3 together with the ignition relay 96, and the high voltage battery 2 and the power converter 10 are connected. The main switch of the vehicle has two on modes. One is an on mode in which the ignition relay 96 is closed and the system main relay 3 is opened, which is sometimes referred to as “accessory on”. The other is an on mode in which both the ignition relay 96 and the system main relay 3 are closed, and is sometimes referred to as “Ready on”. Note that “close the relay (or close the switch)” means to make both ends of the relay (or switch) conductive, and “open the relay (or open the switch)” means the relay (or switch). ) Means that both ends are electrically cut off. Closing the relay (closing the switch) may be expressed as turning on the relay (turning on the switch). Similarly, opening the relay (opening the switch) may be expressed as turning off the relay (turning off the switch).

  Hybrid vehicle 100 also includes sockets (first socket 6a and second socket 6b) for connecting high voltage battery 2 to a device outside the vehicle. The 1st socket 6a and the 2nd socket 6b are outlets which insert the power cable which transmits electric power between the high voltage battery 2 and the apparatus outside a vehicle. The first socket 6a is connected to the power converter side of the system main relay 3 via the first system sub-relay 5a. An AC charger 7 is connected to the second socket 6b, and the AC charger 7 is connected to the high-voltage battery side of the system main relay 3 via the second system sub-relay 5b. The AC charger 7 converts the AC power of the commercial power source into DC power slightly higher than the output voltage of the high voltage battery 2. The first and second system sub relays 5 a and 5 b are also controlled by the HV controller 4. The first socket 6a is used when the electric power of the high voltage battery 2 is directly connected to a device outside the vehicle. The device outside the vehicle is a DC-AC converter that converts the electric power of the high voltage battery 2 into the same AC power as the output of the commercial power supply, a direct current power source for charging the high voltage battery 2, or the like.

  When the first socket 6a is used, it is necessary to close the system main relay 3 together with the first system sub relay 5a. When the system main relay 3 is closed, the high voltage battery 2, the power converter 10, and the motor 91 are electrically connected although the motor 91 is not used. The hybrid vehicle 100 includes a safety device so that current does not flow through the motor 91 when the first socket 6a connected to the power converter side of the system main relay 3 is used. The safety device will be described next.

  FIG. 2 shows a block diagram of a circuit configuration of the motor controller 30. On the left side of the broken line DL in the figure is an auxiliary system circuit sharing the body ground Gb, which is referred to as an ECU circuit 40. The elements in the ECU circuit 40 operate at the TTL level. The power transistor 16a shown on the right side of FIG. 2 is the power transistor in the voltage converter 11 described in FIG. The power transistors in the power transistors 16a and 16b and the inverter 20 are transistors through which the power of the high voltage battery 2 flows, and do not operate unless the voltage is higher than the TTL level. Therefore, the motor controller 30 includes a transistor drive circuit 50 whose operating voltage is higher than the TTL level and separates the ECU circuit 40 from the ground. The circuit on the right side of the broken line DL in FIG. 2 is a transistor drive circuit (excluding the power transistor 16a). The ECU circuit 40 and the transistor drive circuit 50 are insulated and exchange signals via the two photocouplers 46a and 46b. Note that in FIG. 2, the symbol of the independent ground Gh in the transistor drive circuit 50 is different from the body ground Gb. Hereinafter, the ECU circuit 40 and the transistor drive circuit 50 may be collectively referred to as a gate drive circuit.

  Circuits other than the processor 47, the first power supply circuit 41a, the second power supply circuit 41b, the third power supply circuit 51, and the load switch 42 are provided in the same number as the power transistors. The processor 47 has as many gate signal output terminals as power transistors. The circuit shown in FIG. 2 (excluding the processor 47, the first power supply circuit 41a, the second power supply circuit 41b, the third power supply circuit 51, and the load switch 42) is connected to each of the plurality of gate signal output terminals. FIG. 2 representatively shows a gate signal output terminal 47a for the power transistor 16a and a gate drive circuit following the terminal. For the power transistors other than the power transistor 16a, the same gate drive circuit as the circuit of FIG. 2 is provided.

  First, a power supply common to a plurality of gate drive circuits will be described. The ECU circuit 40 includes two power supply circuits (a first power supply circuit 41a and a second power supply circuit 41b). These power supply circuits receive power from the auxiliary battery 95 and generate power for the elements in the ECU circuit 40. The first power supply circuit 41a generates power of the operating voltage (first voltage VCC1) of the power-saving processor 47. The second power supply circuit 41b generates power of the TTL level operating voltage (second voltage VCC2). The power of the second voltage VCC2 is supplied to TTL elements other than the processor 47. The processor 47 is supplied with power of the first voltage VCC1 and the second voltage VCC2. In the processor 47, the power of the second voltage VCC2 is used for communication with a TTL level element connected to the processor 47.

  The transistor drive circuit 50 includes a third power supply circuit 51. The third power supply circuit 51 generates power of a power transistor driving voltage (third voltage VCC3) higher than the TTL level. In other words, the third power supply circuit 51 generates power for the transistor drive circuit. The third power supply circuit 51 is an insulated power supply, for example, a flyback power supply circuit including a transformer.

  The third power supply circuit 51 is connected to the auxiliary battery 95 via the load switch 42. The load switch 42 includes a resistor 44a and a p-type MOSFET transistor 43a as shown in FIG. An ignition relay 96 and an auxiliary battery 95 are connected to the gate of the transistor 43a through a resistor 44a. When the ignition relay 96 is closed, the gate of the transistor 43a becomes HIGH level and the transistor 43a is turned off. That is, the load switch 42 is opened (turned off). The load switch 42 is connected to the processor 47 via the resistor 44b. When the processor 47 drops the gate of the transistor 43a to the LOW level, the transistor 43a is turned on. That is, the load switch 42 is closed (turns on). In the state where the load switch 42 is opened, power is not supplied to the third power supply circuit 51. If the power of the auxiliary battery 95 is not supplied to the third power supply circuit 51, the power transistor 16a (and other power transistors) does not operate. In addition to the load switch 42, the motor controller 30 includes a mechanism that prevents the motor 91 from accidentally flowing current in order to ensure the safety of the motor 91. The mechanism will be described later.

  The logic circuit of the gate drive circuit (ECU circuit 40 and transistor drive circuit 50) will be described. The gate signal output terminal 47a of the processor 47 is connected to the gate of an n-type MOSFET transistor 43b via a NOT circuit 45 and a resistor 44d. The NOT circuit 45 is supplied with power of the second voltage VCC2. A photocoupler 46a is connected to the drain of the transistor 43b. Electric power of the second voltage VCC2 is supplied to the ECU circuit side of the photocoupler 46a through the resistor 44c. The power of the third voltage VCC3 is supplied to the transistor drive circuit side of the photocoupler 46a through the resistor 55a. When the gate signal output terminal 47a is at the LOW level, the output of the NOT circuit 45 is at the HIGH level, and the transistor 43b is turned on. A current flows to the photocoupler 46a through the transistor 43b, and the transistor on the transistor drive circuit side of the photocoupler 46a is turned on. A transistor drive IC 52 is connected to the transistor drive circuit side of the photocoupler 46a. When a current flows through the photocoupler 46a, the input terminal 52a of the transistor drive IC 52 falls to the LOW level. On the transistor drive circuit 50 side, the HIGH level is the level of the third voltage VCC3, and the LOW level is the potential of the independent ground Gh different from the body ground Gb on the ECU circuit side.

  When the input terminal 52a of the transistor driving IC 52 falls to the LOW level, the output terminal 54a of the logic circuit 54 of the transistor driving IC 52 becomes the HIGH level. The output terminal 54a of the logic circuit 54 is connected to the gates of the two transistors 53a and 53b. The two transistors 53a and 53b are connected in series. The high-potential-side transistor 53a is a p-type MOSFET, and its source is connected to the power supply line of the third voltage VCC3 via a resistor 55b. The low-potential-side transistor 53b is an n-type MOSFET, and its source is connected to the independent ground Gh. When the gates of the two transistors 53a and 53b are both HIGH, the high-potential side transistor 53a is turned off and the low-potential side transistor 53b is turned on. As a result, the midpoint of the series connection of the two transistors 53a and 53b (that is, the output terminal 52c of the transistor drive IC 52) becomes the LOW level. The output terminal 52c of the transistor drive IC 52 is connected to the gate of the power transistor 16a via the resistor 55c. A signal line connecting the output terminal 52c of the transistor drive IC 52 and the gate of the power transistor 16a is referred to as a gate drive signal line 59. The gate drive signal line 59 being at the LOW level means that the gate of the power transistor 16a is at the LOW level, and the collector and emitter of the power transistor 16a are blocked.

  When the gate signal output terminal 47a of the processor 47 is at the HIGH level, the HIGH level and the LOW level described above are reversed, the gate of the power transistor 16a is at the HIGH level, and a current flows between the collector and emitter of the power transistor 16a. Flowing.

  Note that the logic circuit 54 of the transistor drive IC 52 has a self-diagnosis function. When any abnormality is detected, the fail terminal 52b held at the LOW level is switched to the HIGH level when it is normal. When the fail terminal 52b switches to the HIGH level, a fail signal is notified to the processor 47 through the photocoupler 46b. Note that the electric power of the second voltage VCC2 is supplied to the ECU circuit side of the photocoupler 46b. When the power of the third voltage VCC3 is supplied to the transistor drive IC 52, the self-diagnosis function operates.

  The above description is a case where the first power supply circuit 41a, the second power supply circuit 41b, and the third power supply circuit 51 are operating. If at least the third power supply circuit 51 is not operating, the gate of the power transistor 16a does not become HIGH level.

  In the gate drive circuit, some mechanism is incorporated so that the gate of the power transistor 16a does not become a HIGH level even if some abnormality occurs in the motor controller 30. The first mechanism is that if the processor 47 does not operate, the load switch 42 is not closed, and therefore the power of the auxiliary battery 95 is not supplied to the third power supply circuit 51. In the second mechanism, the gate signal output terminal 47a of the processor 47 is connected to the body ground Gb via the pull-down resistor 44e. While the processor 47 is not operating, the gate signal output terminal 47a is at the ground level ( That is, it is held at the LOW level. As described above, when the gate signal output terminal 47a is at the LOW level, even if the third power supply circuit 51 is operating, the output terminal 52c of the transistor drive IC 52 is at the LOW level, and the gate of the power transistor 16a is also at the LOW level. . The third mechanism is that the gate drive signal line 59 is connected to the independent ground Gh via the pull-down resistor 55d. The pull-down resistor 55d holds the potential of the gate drive signal line 59 connected to the gate of the power transistor 16a at the ground level while the transistor drive IC 52 is not operating. Therefore, the gate drive signal line 59 is held at the LOW level unless the transistor drive IC 52 is operated and its output terminal 52c is raised to the HIGH level.

  As described above, the gate drive circuit of the motor controller 30 has a circuit configuration in which the power transistor 16a is difficult to turn on even if any abnormality occurs. A mechanism similar to the configuration of FIG. 2 is also provided in the gate drive circuit of another power transistor.

  Further, the motor controller 30 closes the system main relay 3 and transmits electric power to / from a device outside the vehicle through the first socket 6a, while the load switch 42 is opened, based on the measurement values of various sensors. Thus, the power converter 10 has a check function for checking whether or not an abnormality has occurred.

  The check function will be described with reference to FIGS. 3, 4, and 6 are flowcharts of processing when power transmission is performed with a device outside the vehicle. 3, 4, and 6 are realized by the cooperation of the processor 47 of the motor controller 30 and the HV controller 4. Note that the sensor signals (measured values) of the current sensors 14 and 21 and the voltage sensors 13 and 19 described in FIG. 1 are input to the processor 47 of the motor controller 30. Hereinafter, the measured value of the current sensor 14 is referred to as current IL, the measured value of the current sensor 21 is referred to as current IM, the measured value of the voltage sensor 13 is referred to as voltage VL, and the measured value of the voltage sensor 19 is referred to as voltage VH.

  The first socket 6a and the second socket 6b into which the power cable outside the vehicle is inserted are configured to send a signal indicating that to the HV controller 4 when the cable plug is inserted. When the HV controller 4 receives a signal indicating that the plug has been inserted from the first socket 6a or the second socket 6b, the HV controller 4 starts the processing of FIGS.

  The HV controller 4 first closes the ignition relay 96 and connects the auxiliary battery 95 and the power converter 10 (S2). Then, the first power supply circuit 41 a and the second power supply circuit 41 b of the motor controller 30 are activated, and power is started to be supplied to the processor 47. Then, the processor 47 is activated (S3). The processor 47 first sets the gate signal output terminal 47a (and gate signal output terminals for other power transistors) to the LOW level (S4). Next, the processor 47 checks whether or not the measured values of the current sensors 14 and 21, that is, the current IL and the current IM are within the normal range (S5). Here, the normal range is, for example, a range of −0.5 to 0.5 [A]. If either the current IL or the current IM is out of the normal range (S5: NO), the process moves to the abnormal mode (S11). In the abnormal mode S <b> 11, the processor 47 sends an abnormality occurrence to the HV controller 4. The HV controller 4 immediately opens the ignition relay 96 and the system main relay 3 and lights a warning lamp indicating that an abnormality has occurred. The HV controller 4 stores a message indicating that an abnormality has occurred in the diagnostic memory. The diagnostic memory is a non-volatile memory and stores information for service staff to know the vehicle state during vehicle maintenance.

  When the current IL and the current IM are both in the normal range in step S5 (S5: YES), the processor 47 closes the load switch 42 (S6). When the load switch 42 is closed, the third power supply circuit 51 is activated and the transistor drive circuit 50 is activated. At this time, since the gate signal output terminal 47a of the processor 47 is held at the LOW level in step S4, even if the transistor drive circuit 50 is activated, the gate drive signal line 59 connected to the gate of the power transistor is It is held at the LOW level.

  The processor 47 confirms whether or not the fail signal is a normal output after closing the load switch 42 (S7). The fail signal is the level of the fail terminal 52b of the transistor drive IC 52. As described above, when the fail terminal 52b is at the HIGH level, an abnormality has occurred in the transistor drive IC 52. The fail signal is a normal output when the fail terminal 52b is at the LOW level. When the fail signal is not a normal output (S7: NO), the processor 47 shifts to an abnormal mode (S11). The abnormal mode (S11) is as described above.

  When the fail signal is a normal output (S7: YES), the processor 47 transmits a signal (relay on permission signal) permitting the system main relay 3 to be closed to the HV controller 4 (S8). “Close relay” and “turn relay on” are synonymous. The HV controller 4 that has received the relay on permission signal closes the system main relay 3, the first system sub relay 5a, and the second system sub relay 5b, and outputs a transmission permission signal (S9). The transmission permission signal is sent to a device outside the vehicle through the first socket 6a and the second socket 6b. Upon receiving the transmission permission signal, the device outside the vehicle draws power from the high voltage battery 2 or sends power to the high voltage battery 2. The protocol for the power transmission permission signal is defined by the standard.

  Next, the processor 47 of the motor controller 30 waits for a predetermined time (for example, 1 minute) (S10), and then proceeds to the processing of S12. The processor 47 confirms again whether or not the fail signal of the transistor drive IC 52 is a normal output (S12). If the fail signal is a normal output, the processor 47 opens the load switch 42 (S12: YES, S14). When the load switch 42 is opened, the transistor drive circuit 50 stops. If the fail signal is not a normal output in step S12, the process shifts to an abnormal mode (S12: NO, S13). The abnormal mode is as described above.

  While the power is being transmitted, the processor 47 keeps the load switch 42 open, and the measured values of the current sensors 14 and 21 and the voltage sensors 13 and 19 (current IL, current IM, voltage VL, voltage VH). Based on the above, it is periodically checked whether an abnormality has occurred in the high voltage system of the power converter 10. The routine is the process from step S15 to S21.

  The processor 47 confirms whether or not the measured value of the current sensor 14 (current IL flowing through the reactor 15) is within the normal range (S15). The normal range is, for example, a range of −0.5 to 0.5 [A]. If the current IL is out of the normal range, the processor 47 proceeds to transistor drive circuit check processing (S16). FIG. 5 shows a flowchart of the transistor drive circuit check process. In the transistor drive circuit check process, the processor 47 first closes the load switch 42 (S31). When the load switch 42 is closed, electric power is supplied from the auxiliary battery 95 to the third power supply circuit 51, and electric power (third voltage VCC3) for the transistor drive circuit 50 is generated. The power of the third voltage VCC3 is supplied to the transistor drive IC 52, and the transistor drive IC 52 starts self-diagnosis. When the transistor drive IC 52 detects an abnormality, the transistor drive IC 52 switches the fail terminal 52b at the LOW level to HIGH. The processor 47 monitors the fail signal (the voltage level of the fail terminal 52b) via the photocoupler 46b. When the fail signal is HIGH (that is, when the output is not normal), the processor 47 shifts to an abnormal mode (S33). (S32: NO, S33). If the fail signal is a normal output (S32: YES), it is estimated that the current IL is outside the normal range in step S15 is caused by noise or the like. In that case, the processor 47 notifies the host HV controller 4 of a signal notifying that the power converter 10 is operating normally (S34). Then, the processor 47 opens the load switch 42 to stop the transistor drive circuit 50 (S35), and proceeds to step S17.

  In step S17, the processor 47 checks whether or not the measured value (current IM) of the current sensor 21 provided on the AC output line of the inverter 20 is in the normal range. When the current IM is outside the normal range, a transistor drive circuit check process is executed (S17: NO, S18). The transistor drive circuit check process is as described with reference to FIG. If the current IM is in the normal range, or if no abnormality is detected in the transistor drive circuit check process (S18), the processor 47 next measures the measured values (voltage VL, voltage VH) of the voltage sensors 13, 19. Is used to check whether the difference is within a predetermined normal range (S19). The normal range here is set in the range of −5.0 to 5.0 [V], for example. When the difference between the voltage VL and the voltage VH is out of the normal range, the process proceeds to the transistor drive circuit check process (S19: NO, S20) as in the case of steps S15 and S17. When the difference between the voltage VL and the voltage VH is within a predetermined normal range (S19: YES), or when no abnormality is detected in the transistor drive circuit check process (S20), the process of the processor 47 proceeds to step S21. Move. The processor 47 repeats the above-described processing of steps S15 to S19, that is, the check processing based on the measurement values of various sensors until power transmission is completed (S21: NO, S15).

  When the processor 47 receives a signal indicating the end of power transmission from the host HV controller 4, the determination in step S21 is YES, and the process proceeds to step S41 (FIG. 6). When the HV controller 4 receives a signal indicating that the plug is not inserted from both the first socket 6a and the second socket 6b, the HV controller 4 transmits a signal indicating that the power transmission is completed to the motor. It transmits to the controller 30 (processor 47).

  When the power transmission is completed, the processor 47 finally closes the load switch 42 again (S41 in FIG. 6), activates the transistor drive circuit 50, and checks the fail signal from the transistor drive IC 52 (S42). If the fail signal is not normal output, the process proceeds to the abnormal mode in step S43. If the fail signal is a normal output, a relay off permission signal for permitting the system main relay 3 to be opened is sent to the HV controller 4 in step S45 (S44). The HV controller 4 that has received the relay off permission signal opens the system main relay 3 and opens the first system sub-relay 5a and the second system sub-relay 5b (S45). Finally, the HV controller 4 opens the ignition relay 96 (S46). The power supply to the auxiliary machine group including the motor controller 30 of the power converter 10 is stopped, and the main switch (not shown) of the vehicle returns to the off state.

  In FIG. 6, the process for opening the load switch 42 corresponding to the process for closing the load switch 42 in step S41 is not clearly shown. However, when the ignition relay 96 is opened in step S46, the power supply to the motor controller 30 is stopped. Therefore, the power supply to the transistor drive circuit 50 is stopped without opening the load switch 42.

  As described above, the processor 47 (motor controller 30) and the HV controller 4 operate the load switch 42 while the system main relay 3 is closed and power is transmitted between the high-voltage battery 2 and a device outside the vehicle. Based on the measured values of the sensors (current sensors 14, 21 and voltage sensors 13, 19) in the open state, it is checked whether or not an abnormality has occurred in the power converter 10. The load switch 42 is a switch for switching between connection and disconnection between the auxiliary battery 95 and the third power supply circuit 51 (power supply circuit for operating the transistor drive circuit 50). When the measured value of the sensor is out of the normal range, the load switch 42 is closed, the transistor drive circuit 50 is started, the diagnosis result (fail signal) of the self-diagnosis function of the transistor drive IC 52 is confirmed, and the transistor drive circuit 50 Recheck whether an abnormality has occurred.

  The hybrid vehicle 100 is excellent in safety measures for the motor 91 when power transmission is performed with an external device. The safety measure here is a mechanism that makes it difficult for a current to flow through the motor 91 even when an abnormality occurs in the power converter 10 connected between the high-voltage battery 2 and the motor 91. One of the mechanisms is that the LOW level of the gate drive signal is predetermined with respect to the ground potential between the signal line (gate drive signal line 59) connected to the gate of the power transistor and the ground (independent ground Gh). A pull-down resistor 55d for holding at a potential of. Another mechanism for safety measures is to provide a pull-down resistor 44e between the body ground Gb and the gate signal output terminal 47a of the processor 47 that outputs a TTL level gate drive signal. As a software safety measure, the HV controller 4 and the motor controller 30 (processor 47) may use the measured values of the various sensors of the power converter 10 while the load switch 42 is open during power transmission. The abnormality check of the power converter 10 is performed based on the above.

  Points to be noted regarding the technology described in the embodiments will be described. 3 to 6 are processes when a plug is inserted into the first socket 6a or the second socket 6b in a state where the main switch of the vehicle is off. When the main switch is in the ON state, the processing in steps S2 to S6 and the processing in which step S45 is omitted in the flowcharts of FIGS.

  In addition to the first power supply circuit 41a and the second power supply circuit 41b, the ECU circuit 40 of the motor controller 30 is provided with another power supply circuit that generates an intermediate voltage and a power supply circuit for operating a sensor such as a resolver. It may be. These power supply circuits may be connected between the auxiliary battery 95 and the load switch 42.

  The load switch 42 according to the embodiment corresponds to an example of a “power supply circuit switch” in the claims. The power supply circuit switch is not limited to the configuration of the load switch 42 of the embodiment as long as it is a device that can switch connection and disconnection between the auxiliary battery 95 and the third power supply circuit.

  The motor controller 30 and the HV controller 4 when executing the processes of FIGS. 3 to 6 correspond to an example of “controller” in the claims. As in the embodiment, the “controller” in the claims is not limited to one processor, and the function of the “controller” may be realized by cooperation of several processors.

  The third power supply circuit 51 of the embodiment corresponds to an example of a “power supply circuit” in the claims. The pull-down resistor 55d in the embodiment corresponds to an example of a “pull-down resistor” in the claims.

  The technology of the embodiment may be applied to a hybrid vehicle including both a motor and an engine for traveling, and an automobile including a traveling motor but not including an engine.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2: High voltage battery 3: System main relay 4: HV controller 5a: First system sub relay 5b: Second system sub relay 6a: First socket 6b: Second socket 7: AC charger 10: Power converter 11: Voltage converter 12: Filter capacitor 13, 19: Voltage sensor 14, 21: Current sensor 15: Reactor 16a, 16b: Power transistor 17a, 17b: Diode 20: Inverter 30: Motor controller 40: ECU circuit 41a: First power supply circuit 41b : Second power supply circuit 42: load switches 43a, 43b: transistors 44a-44e: resistor 45: NOT circuit 46a, 46b: photocoupler 47: processor 47a: gate signal output terminal 50: transistor drive circuit 51: third power supply circuit 52 : Transistor drive I
53a, 53b: Transistor 54: Logic circuits 55a-55d: Resistor 59: Gate drive signal line 91: Motor 92: Engine 95: Auxiliary battery 96: Ignition relay 100: Hybrid vehicle

Claims (1)

A high voltage battery for storing electric power for driving a motor for traveling;
An auxiliary battery that supplies power to a group of devices that operate at a voltage lower than the output voltage of the high-voltage battery;
A power converter connected between the high-voltage battery and the motor, and converting power of the high-voltage battery into driving power of the motor;
A system main relay connected between the high voltage battery and the power converter;
A socket for connecting a power cable connected to the power converter side of the system main relay and transmitting power between the high voltage battery and a device outside the vehicle;
A controller, and
The power converter is
A power transistor that converts electric power of the high-voltage battery into driving power of a motor for traveling;
A transistor drive circuit for generating a drive signal to be supplied to the gate of the power transistor;
A power supply circuit that receives power supply from the auxiliary battery and generates power for the transistor drive circuit;
A power supply circuit switch for switching connection and disconnection between the auxiliary battery and the power supply circuit;
A sensor for measuring a current or voltage of a power line through which the power of the high-voltage battery flows;
With
The transistor drive circuit includes a pull-down resistor connected between a signal line connected to the gate and the ground,
While the system main relay is closed and power is transmitted between the high-voltage battery and a device outside the vehicle, the controller opens the power circuit switch based on the measured value of the sensor. An electric vehicle for checking whether or not an abnormality has occurred in the power converter.

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