JP2020078187A - vehicle - Google Patents

Abstract

To provide a vehicle which is mounted with a power storage device capable of being charged with power from an external charging device, and which suppresses the welding of a system main relay.SOLUTION: A vehicle 20 includes: a motor 22; a battery 28 connected to the motor via a first power line 26; a first relay 32 provided on the first power line; a connection part 34 which is connected to a side closer to the motor than the first relay via a second power line 38 and can be connected to a charging stand 60; and a second relay 36 provided on the second power line. The vehicle 20 allows an external charging process for charging the battery with power from the charging stand while the connection part is connected to the charging stand, and the first relay and the second relay are both in an ON-state. In the vehicle 20, at the time of finishing the external charging process, when an input current in a power storage device is equal to or greater than a prescribed current after an OFF-command to the second relay is output, the motor is controlled so that the input current becomes less than the prescribed current, and an OFF-command is output to the first relay while the input current is less than the prescribed current.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle.

  Conventionally, as a vehicle of this type, a motor that outputs motive power for traveling, a power storage device that supplies power to the motor, a system main relay provided between the motor and the power storage device, and a power supply connector of an external charging device There is proposed a power receiving connector that can be coupled with a power receiving connector, a charging relay that is connected to the power receiving connector and that is connected to a power storage device via a system main relay, and a charging ECU (for example, see Patent Document 1). .. In this vehicle, whether the charging ECU is supplied with power from the external charging device to the power receiving connector when charging the power storage device with the power from the external charging device in a state where the system main relay and the charging relay are closed. It is determined whether or not, and when the power from the external charging device is not supplied to the power receiving connector, the system main relay is opened.

JP, 2018-42370, A

  In the vehicle described above, even if the control device outputs an off command to the charging relay to end external charging, current may continue to flow from the external charging device to the power storage device due to welding of the charging relay. If an OFF command is output to the system main relay in this state, the system main relay may also be welded.

  Therefore, an object of the present disclosure is to suppress welding of a system main relay in a vehicle equipped with a power storage device that can be charged using electric power from an external charging device.

  The vehicle of the present invention adopts the following means in order to achieve the above-mentioned main object.

The vehicle of the present invention is
A motor,
A power storage device connected to the motor via a first power line;
A first relay provided in the first power line;
A connection part that is connected to the motor side of the first power line rather than the first relay via a second power line and is connectable to an external power supply device;
A second relay provided on the second power line;
A control device for controlling the motor, the first relay, and the second relay;
Equipped with
A vehicle in which the connection unit is connected to the external power supply device and in which the first relay and the second relay are both turned on, the power storage device is charged using electric power from the external power supply device, which is capable of external charging processing. And
When the input current of the power storage device is equal to or more than a predetermined current after outputting the OFF command of the second relay when ending the external charging process, the control device sets the input current to be less than the predetermined current. Controlling the motor and outputting an OFF command to the first relay in a state where the input current is less than the predetermined current,
Is the gist.

  In the vehicle of the present invention, when the external charging process is terminated, the motor is controlled so that the input current becomes less than the predetermined current when the input current of the power storage device is equal to or more than the predetermined current after the second relay OFF command is output. Then, the OFF command is output to the first relay when the input current is less than the predetermined current. As a result, welding of the first relay can be suppressed.

  In the vehicle of the present invention, when controlling the motor, the control device may control the motor such that electric power is consumed by the motor without outputting torque from the motor. As a result, torque is not output from the motor, motor power is consumed, and the input current of the power storage device can be reduced.

It is a block diagram which shows the outline of a structure of the electric vehicle 20 as one Example of this invention. 6 is a flowchart showing an example of a processing routine executed by vehicle ECU 40. It is explanatory drawing which shows an example of a mode at the time of ending an external charging process.

  Next, modes for carrying out the present invention will be described using examples.

FIG. 1 is a configuration diagram showing an outline of the configuration of an electric vehicle 20 equipped with a power supply device as an embodiment of the present invention. As illustrated, the electric vehicle 20 of the embodiment includes a motor 22, an inverter 24, a battery 28 as a power storage device, a system main relay 32, a vehicle-side connecting portion 34, a charging relay 36, and a vehicle electronic device. A control unit (hereinafter referred to as “vehicle ECU”) 40.

  The motor 22 is configured as, for example, a synchronous generator motor, and is connected to a drive shaft that is connected to drive wheels via a differential gear. The inverter 24 is used to drive the motor 22 and is connected to the battery 28 via the power line 26. The motor 22 is rotationally driven by the vehicle ECU 40 performing switching control of a plurality of switching elements (not shown) of the inverter 24.

  The battery 28 is configured as, for example, a lithium ion secondary battery or a nickel hydrogen secondary battery, and is connected to the inverter 24 via the power line 26 as described above. The system main relay 32 is provided in the electric power line 26, is on / off controlled by the vehicle ECU 40, and connects and disconnects the battery 28 side and the inverter 24 side.

  The vehicle-side connecting portion 34 is connected to the inverter 24 side of the power line 26 rather than the system main relay 32 via the power line 38. The vehicle-side connecting portion 34 is configured to be connectable to the charging-side connecting portion 64 of the charging stand 60 capable of supplying a direct current to the electric vehicle 20 at a charging point such as a home or a charging station.

  Here, the description of the electric vehicle 20 will be temporarily interrupted, and the charging station 60 will be described. The charging stand 60 includes a charging device 62, a charging side connection portion 64, and a charging electronic control unit (hereinafter, referred to as “charging ECU”) 68.

  The charging device 62 converts AC power from an AC power supply such as a household power supply or an industrial power supply into DC power and supplies the DC power to the charging side connection unit 64 (electric vehicle 20) via the power line 63. The charging-side connecting portion 64 is configured to be connectable to the vehicle-side connecting portion 34 of the electric vehicle 20.

  Although not shown, the charging ECU 68 is configured as a microprocessor centered on a CPU, and in addition to the CPU, includes a ROM that stores a processing program, a RAM that temporarily stores data, an input / output port, and a communication port. Prepare Signals from various sensors and the like are input to the charging ECU 68 via an input port. For example, a connection detection signal from a connection detection sensor that is attached to the charging ECU 68 and that detects the connection between the charging-side connecting portion 64 and the vehicle-side connecting portion 34 can be cited. From the charging ECU 68, a control signal or the like to the charging device 62 is output via the output port. The charging ECU 68 can communicate with the vehicle ECU 40 of the electric vehicle 20.

  Returning to the description of the electric vehicle 20. The charging relay 36 is provided on the power line 38, and is on / off controlled by the vehicle ECU 40 to connect and disconnect the power line 26 side and the vehicle side connecting portion 34 side.

  Although not shown, the vehicle ECU 40 is configured as a microprocessor including a CPU, and in addition to the CPU, includes a ROM that stores a processing program, a RAM that temporarily stores data, an input / output port, and a communication port. Prepare A signal from the current sensor 30 or the like is input to the vehicle ECU 40 via the input port. Control signals to the inverter 24, the system main relay 32, and the charging relay 36 are output from the vehicle ECU 40 via the output port. The vehicle ECU 40 calculates the storage ratio SOC of the battery 28 based on the integrated value of the current IB of the battery 28 from the current sensor 30. Further, the vehicle ECU 40 can communicate with the charging ECU 68 of the charging stand 60.

  In the electric vehicle 20 of the embodiment configured in this manner, the vehicle-side connecting portion 34 and the charging-side connecting portion 64 are connected by an operator (for example, a driver) at a charging point such as a home or a charging station in a system-off state, When the operation unit of the charging stand 60 is operated and an external charging process for charging the battery 28 using the electric power from the charging stand 60 is instructed, the charging ECU 68 outputs a signal indicating that the execution of the external charging process is instructed. Is transmitted to the vehicle ECU 40. Upon receiving this signal, vehicle ECU 40 turns on system main relay 32 and charging relay 36, and transmits a charging start request to charging ECU 68. When receiving the charging start request, charging ECU 68 starts execution of charging control for controlling charging device 62 so that electric vehicle 20 is supplied with electric power. As a result, the battery 28 is supplied to the battery 28 via the power lines 38 and 26 from the charging device 62, and the battery 28 is charged. Then, when the state of charge SOC of the battery 28 reaches or exceeds the threshold value Sref (for example, about 85% to 95%), the charging end request is transmitted to the charging ECU 68. When receiving the charging end request, charging ECU 68 ends the execution of charging control. This completes the charging of the battery 28. Then, vehicle ECU 40 turns off charging relay 36 and system main relay 32. In this way, the external charging process ends.

  Next, the operation of the electric vehicle 20 of the embodiment configured in this way, particularly the operation when the external charging process is finished (specifically, when the charging relay 36 and the system main relay 32 are turned off) will be described. .. FIG. 2 is a flowchart showing an example of a processing routine executed by the vehicle ECU 40 at this time.

  When the processing routine of FIG. 2 is executed, vehicle ECU 40 outputs an off command to charging relay 36 (step S100). When an off command is output from the vehicle ECU 40, the charging relay 36 is turned off when it is normal (not welded), and is kept on when it is welded. At this time, if communication abnormality between the vehicle ECU 40 and the charging ECU 68 occurs, the power supply from the charging device 62 is continued, current continues to flow in the power lines 38 and 26, and the battery 28 is continuously charged. Sometimes.

  Subsequently, the current IB flowing from the current sensor 30 to the battery 28 is input (step S110), and the absolute value of the input current IB is compared with the threshold value Iref (step S120). Here, the threshold value Iref is a threshold value used to determine whether or not the system main relay 32 can be normally turned off (without welding), and for example, 4A, 5A, 6A or the like is used. When the absolute value of the current IB is less than the threshold value Iref, a system main relay cutoff command is output (step S140), and this routine ends. The system main relay 32 is turned off when an off command is output from the vehicle ECU 40.

  When the absolute value of the current IB is greater than or equal to the threshold value Iref in step S120, the motor 22 is controlled so that the current IB flowing through the battery 28 becomes 0 (step S130), and the process returns to step S110. Here, in the process of step S130, the inverter 24 is controlled so that only the d-axis current flows through the motor 22. As a result, electric power is consumed by the motor 22 without outputting torque from the motor 22, and the current IB flowing through the battery 28 can be reduced.

  Then, after that, when the absolute value of the current IB becomes less than the threshold value Iref in step S120, a cutoff command is output to the system main relay 32 (step S140), and this routine is ended.

  FIG. 3 is an explanatory diagram showing an example of a state at the time of ending the external charging process (specifically, when turning off the charging relay 36 and the system main relay 32). As shown in the figure, the vehicle ECU 40 outputs an off command to the charging relay 36 at time t2 after transmitting the charging end request to the charging ECU 68 at time t1. However, when the charging relay 36 is welded, the charging relay 36 is held on. Then, at time t3, when the absolute value of the current IB (charging current) flowing in the battery 28 is equal to or greater than the threshold value Iref, the inverter 24 is controlled so that torque is not output from the motor 22 and power is consumed by the motor 22. As a result, the absolute value of the current IB flowing through the battery 28 decreases, and when the absolute value of the current IB becomes less than the threshold value Iref at time t4, an off command is output to the system main relay 32. By turning off the system main relay 32 in this manner, welding of the system main relay 32 can be suppressed. The driving of the motor 22 is preferably stopped after the system main relay 32 is turned off and when the power supply from the charging device 62 is stopped.

  In the electric vehicle 20 of the embodiment described above, when the external charging process is terminated, after the OFF command of the charging relay 36 is output, if the absolute value of the current IB flowing in the battery 28 is equal to or greater than the threshold value Iref, The motor 22 is controlled so that the absolute value of IB becomes less than the threshold value Iref, and an off command is output to the system main relay 32 in a state where the absolute value of the current IB is less than the threshold value Iref. Thereby, welding of the system main relay 32 can be suppressed.

  In the embodiment, the electric vehicle 20 is provided with the motor 22 and the battery 28. However, the electric vehicle 20 may be provided with the motor and the battery, and the hybrid vehicle may be provided with an engine in addition to the motor. In the electric vehicle 20 of the embodiment, the battery 28 is used as the power storage device, but a capacitor may be used.

  In the embodiment, the motor 22 corresponds to a “motor”, the battery 28 corresponds to a “power storage device”, the system main relay 32 corresponds to a “first relay”, and the vehicle-side connecting portion 34 corresponds to a “connecting portion”. The charging relay 36 corresponds to the “second relay”, and the vehicle ECU 40 corresponds to the “control device”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the section of means for solving the problem. This is an example for specifically explaining the mode for carrying out the invention, and does not limit the elements of the invention described in the column of means for solving the problem. That is, the interpretation of the invention described in the column of means for solving the problem should be made based on the description in that column, and the embodiment is the invention of the invention described in the column of means for solving the problem. This is just a specific example.

  Although the embodiments for carrying out the present invention have been described above with reference to the embodiments, the present invention is not limited to these embodiments, and various embodiments are possible within the scope not departing from the gist of the present invention. Of course, it can be implemented.

  INDUSTRIAL APPLICABILITY The present invention can be used in the vehicle manufacturing industry and the like.

  20 electric vehicle, 22 motor, 24 inverter, 26, 38, 63 power line, 28 battery, 30 current sensor, 32 system main relay, 34 vehicle side connection part, 36 charging relay, 40 vehicle electronic control unit (vehicle ECU) , 60 charging stand, 62 charging device, 64 charging side connection part, 68 electronic control unit for charging (charging ECU).

Claims (1)

A motor,
A power storage device connected to the motor via a first power line;
A first relay provided in the first power line;
A connection part that is connected to the motor side of the first power line rather than the first relay via a second power line and is connectable to an external power supply device;
A second relay provided on the second power line;
A control device for controlling the motor, the first relay, and the second relay;
Equipped with
A vehicle in which the connection unit is connected to the external power supply device and in which the first relay and the second relay are both turned on, the power storage device is charged using electric power from the external power supply device, which is capable of external charging processing. And
When the input current of the power storage device is equal to or more than a predetermined current after outputting the OFF command of the second relay when ending the external charging process, the control device sets the input current to be less than the predetermined current. Controlling the motor and outputting an OFF command to the first relay in a state where the input current is less than the predetermined current,
vehicle.

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