Apparatus for vehicle external discharge, and vehicle

Abstract

The present invention belongs to the technical field of electric vehicles and relates to an apparatus for vehicle external discharge, and a vehicle. In the present invention, an inverter module in a motor control unit is reused, and the changeover of the connection between the motor control unit and a discharge interface and the connection between the motor control unit and a driving electric motor is realized by means of a changeover switch unit, wherein the inverter module is connected to the discharge interface in a scenario where a vehicle requires an external discharge condition, and the inverter module is connected to the driving electric motor when the vehicle is in a traveling state. In the present invention, reusing an existing motor control unit of a vehicle to realize vehicle external discharge causes minimal changes to the vehicle itself, and it is not necessary to additionally install a DCAC bidirectional on-board charger, thereby reducing the weight and costs of the vehicle; moreover, the changeover between the connection between the motor control unit and a driving electric motor and the connection between the motor control unit and a discharge interface can be realized, thereby enabling the vehicle to choose between a traveling state and an external discharge state.

Description

Device for discharging a vehicle externally and vehicle Technical Field

[0001] The invention belongs to the technical field of electric vehicles, and in particular relates to a device for discharging electric power from a vehicle and a vehicle. Background Art

[0002] With the development of electric vehicles, they are no longer limited to being just tools for carrying passengers. The market requires electric vehicles to have more additional functions, which has given rise to more concepts, such as vehicle-to-grid (V2G), vehicle-to-vehicle (V2V), vehicle-to-local microgrid (V2H), and vehicle-to-various power loads (V2L). Many national and regional standards have planned vehicle external discharge function standards. These standards will give electric vehicles more value-added services. Therefore, the development of vehicle external discharge function will greatly expand the additional functions of electric vehicles and provide value-added services in various special scenarios, such as natural disasters, road rescue, outdoor camping, etc.

[0003] The current industry standard is to install a DCAC bidirectional onboard charger in the vehicle, as shown in Figure 1. When the vehicle is discharging externally, the power module operates in DC2AC mode, providing both vehicle-to-vehicle AC discharge (V2L) and vehicle-to-vehicle AC charging (V2V). However, installing an additional DCAC bidirectional onboard charger increases vehicle cost and weight.

[0004] Summary of the Invention

[0005] The object of the present invention is to provide a device for discharging a vehicle externally and a vehicle, so as to solve the problem of increased vehicle cost and weight caused by the prior art of achieving external discharge of the vehicle by adding a DCAC bidirectional on-board charger.

[0006] To solve the above technical problems, the present invention provides a vehicle external discharge device, including a battery, an inverter module in a motor controller, a switching switch unit and a discharge interface; the DC end of the inverter module is connected to the battery, the AC end of the inverter module is connected to the first end of the switching switch unit, the second end of the switching switch unit is connected to the discharge interface, and the third end of the switching switch unit is used to connect to the drive motor on the vehicle. The switching switch unit is used to connect the inverter module and the discharge interface when the vehicle meets the external discharge conditions, and is also used to connect the inverter module and the drive motor when the vehicle is in a driving state.

[0007] Furthermore, the switching switch unit includes a motor switch and a discharge interface switch, wherein one end of the motor switch and the discharge interface switch are connected to serve as the first end of the switching switch unit, the other end of the motor switch serves as the third end of the switching switch unit, and the other end of the discharge interface switch serves as the second end of the switching switch unit; and when the inverter module and the discharge interface are connected, the motor switch is disconnected and the discharge interface switch is closed, and the inverter module and the discharge interface are connected; when the discharge interface switch is disconnected and the motor switch is closed, the inverter module and the drive motor are connected.

[0008] Furthermore, the discharge interface is multiplexed with the charging interface on the vehicle.

[0009] Furthermore, it also includes a meter, which is used to change the working state of the switching switch unit through the switch drive controller of the switching switch unit according to the user's mode selection instruction; the mode includes: external discharge mode.

[0010] Furthermore, the external discharge conditions include: detecting that the battery is plugged in, the user selecting the external discharge mode, and the battery meeting the external discharge boundary conditions.

[0011] Furthermore, the external discharge boundary conditions include: detecting the charging gun presence signal; the battery capacity is greater than the capacity setting value; the minimum voltage of the battery's single cell is greater than or equal to the battery voltage setting value; there is no battery fault; and the battery management system continues to receive V2X command messages.

[0012] Furthermore, when the switching unit is in a state of conducting between the inverter module and the discharge interface, if any external discharge boundary condition is not satisfied, the switching unit is caused to disconnect the conduction between the inverter module and the discharge interface.

[0013] In order to solve the above technical problems, the present invention also provides a vehicle, including a device for discharging the vehicle to the outside, the device for discharging the vehicle to the outside includes a battery and a discharge interface, and the device for discharging the vehicle to the outside also includes a switching switch unit and an inverter module in a motor controller; the DC end of the inverter module is connected to the battery, the AC end of the inverter module is connected to the first end of the switching switch unit, the second end of the switching switch unit is connected to the discharge interface, and the third end of the switching switch unit is connected to the drive motor on the vehicle. The switching switch unit is used to enable conduction between the inverter module and the discharge interface when the vehicle meets the external discharge conditions, and is also used to enable conduction between the inverter module and the drive motor when the vehicle is in a driving state.

[0014] Furthermore, the switching switch unit includes a motor switch and a discharge interface switch, wherein one end of the motor switch and the discharge interface switch are connected to serve as the first end of the switching switch unit, the other end of the motor switch serves as the third end of the switching switch unit, and the other end of the discharge interface switch serves as the second end of the switching switch unit; and when the motor switch is disconnected and the discharge interface switch is closed, conduction is maintained between the inverter module and the discharge interface; when the discharge interface switch is disconnected and the motor switch is closed, conduction is maintained between the inverter module and the drive motor.

[0015] Furthermore, the discharge interface and the charging interface on the vehicle are multiplexed.

[0016] The beneficial effects of the above technical solution are as follows: the overall idea of ​​the present invention is to realize external discharge of the vehicle by reusing the inverter module in the motor controller. Specifically, a switching switch unit is provided between the inverter module, the drive motor and the discharge interface. The switching switch unit can put the inverter module and the drive motor in a conductive state when the vehicle is in normal driving state, so that the vehicle can still provide power to the drive motor to enable it to work normally without the need for external charging. The switching switch unit can also put the inverter module and the discharge interface in a conductive state when the vehicle needs to discharge externally, thereby discharging externally through the battery in the vehicle and the inverter module in the motor controller. This external discharge method has little effect on the vehicle itself and does not require an additional DCAC bidirectional on-board charger, reducing the weight and cost of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG1 is a schematic diagram of a common vehicle external discharge solution in the prior art;

[0018] FIG2(a), FIG2(b), and FIG2(c) are schematic diagrams of three different vehicle external discharge embodiments of the vehicle external discharge device of the present invention;

[0019] FIG3 is a schematic diagram of a vehicle external discharge scheme of an embodiment of a vehicle external discharge device of the present invention;

[0020] FIG4 is a flow chart of vehicle external discharge control according to an embodiment of a method for vehicle external discharge of the present invention. DETAILED DESCRIPTION

[0021] The present invention provides a vehicle external discharge device, specifically comprising a battery, an inverter module in a motor controller, a switching unit, and a discharge interface; the DC end of the inverter module is connected to the battery, the AC end is connected to the first end of the switching unit, the second end of the switching unit is connected to the discharge interface, and the third end of the switching unit is used to connect to the drive motor on the vehicle. The switching unit is used to connect the inverter module and the discharge interface when the vehicle meets the external discharge conditions, and is also used to connect the inverter module and the drive motor when the vehicle is in a driving state. The present invention reuses the inverter module in the motor controller, with minimal changes to the vehicle itself. There is no need to add an additional DCAC bidirectional on-board charger, and the discharge function is achieved at a relatively low cost. Compared with the method of adding a DCAC bidirectional on-board charger in the prior art, the weight and cost of the vehicle are reduced. In addition, the present invention also provides a vehicle including the above-mentioned vehicle external discharge device.

[0022] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0023] Example of a device for discharging a vehicle externally:

[0024] The three usage scenarios of vehicle external discharge are shown in Figures 2(a), 2(b) and 2(c). The present invention includes three usage modes of vehicles: vehicle to grid discharge (V2G), vehicle to vehicle discharge (V2V) and vehicle to electrical equipment discharge (V2L).

[0025] The motor controller itself has the AC-DC conversion function, and the motor drive and AC charging (the AC charging is to charge the battery on the vehicle) or AC discharging (the AC discharging is to discharge the battery on the vehicle to the outside) have mutually exclusive logic. For example, external discharge or vehicle charging is not allowed while the vehicle is driving, and the vehicle is not allowed to drive during charging or external discharge. In this way, a switch control box (that is, a switching switch unit) can be added between the drive motor and the electrical controller. When the vehicle is parked, the AC output of the motor controller can be switched to the charging port through the switch control box. In this way, the user can obtain AC power at the charging port to realize the external discharge function.

[0026] At the same time, the vehicle controller VCU (Vehicle Control Unit), motor controller MCU (Motor Control Unit), battery management system BMS (Battery Management System), V2G switch drive controller, and instrumentation need to be coordinated through set logic.

[0027] An AC discharge interface is provided to provide vehicle-to-electrical equipment discharge (V2L) or vehicle-to-vehicle charging (V2V).

[0028] This embodiment provides a device for discharging power from a vehicle to the outside, including a battery, a battery management system (BMS), a motor controller (MCU), a switch control box, a V2G switch control driver, a charge / discharge interface (i.e., the charge / discharge interface in FIG3 ), a vehicle controller (VCU), and an instrument. The motor controller MCU includes an inverter module, the DC end of which is connected to the battery. The motor controller MCU is used to connect to the battery, the switch control box, and the battery management system (BMS). The battery management system (BMS) is connected to a V2G switch control driver installed on the switch control box, and controls the opening and closing of a switch in the switch control box by controlling the V2G switch control driver. The switch control box is connected to a drive motor and a charge / discharge interface, and includes a motor switch and a charge / discharge interface switch. The motor switch Km is connected to the drive motor to control whether the inverter and the drive motor are conductive, and the charge / discharge interface switch K1 is connected to the charge / discharge interface to control whether the inverter and the charge / discharge interface are conductive. When the vehicle is in motion, the corresponding switch control box's logic is to disconnect the charging and discharging interface switch K1 and close the motor switch Km. During external discharge or AC charging, the drive motor is inoperative, preventing the vehicle from driving. The corresponding switch control box's logic is to disconnect the motor switch Km and close the charging and discharging interface switch K1. The charging and discharging interface is a modification of the vehicle's original charging interface (this modification is known in the art), allowing the vehicle's charging interface to also serve as a discharging interface. In other words, the discharging and charging interfaces are integrated into a single interface.

[0029] It should be noted that the "charge-discharge interface" in this embodiment can perform both discharge and charge functions. It serves as a discharge interface when the battery needs to be discharged, and as a charge interface when the vehicle's battery needs to be charged. Accordingly, the inverter in the motor controller no longer merely performs an inversion function but also a rectification function. As can be seen in Figure 3, two parallel branches are provided between the battery and the inverter. The first branch is connected in series with only a switch, while the second branch is connected in series with a switch and a diode for reverse power protection. When the switch on the first branch is closed and the switch on the second branch is open, the battery can be charged. When the switch on the second branch is closed and the switch on the first branch is open, the battery can only be discharged. Of course, the focus of the vehicle discharge device provided in this embodiment is to perform the vehicle discharge function. The discharge interface does not need to be integrated with the vehicle's charging interface. In this case, the vehicle has two independent interfaces: a charging interface and a discharge interface. Accordingly, the "charge-discharge interface switch" connected to the discharge interface is a "discharge interface switch."

[0030] The vehicle control unit (VCU) connects to the instrument cluster, motor controller MCU, and battery management system (BMS). The VCU sets the current operating mode and allows the meter to start and stop these modes. The meter displays discharge modes: V2V, V2G, and V2L. V2G has two submenus: AC220V and AC380V. The meter also displays "Discharge Start" and "Discharge Stop." Furthermore, the meter can set a target SOC value for V2X discharge, automatically stopping the discharge process once it reaches that value. BMS power battery discharge boundary conditions can also be set to protect the battery. This is shown in Figure 3.

[0031] The specific process when the vehicle discharges externally is as follows:

[0032] 1) When the charging / discharging interface is plugged in, the battery management system detects the plug-in and sets mutual exclusion logic, preventing the vehicle from driving. The user selects the external discharge mode through the instrument panel. After receiving the instrument panel information, the vehicle controller issues the vehicle external discharge instruction. If the battery management system determines that the battery does not meet the external discharge boundary conditions, the instrument panel will display that the vehicle is currently not allowed to discharge externally. If the battery management system determines that the battery meets the external discharge boundary conditions, the battery management system sends a command to the switch control driver to disconnect the motor switch Km in the switch control box and close the charging / discharging interface switch K1, thus starting the vehicle external discharge.

[0033] 2) During the battery discharge process, the battery management system continues to determine whether the battery meets the discharge boundary conditions. If the battery does not meet the discharge boundary conditions, the battery management system stops discharging, the charge and discharge interface switch K1 is disconnected, and the meter indicates that the battery is about to over-discharge and discharge has stopped. If the battery meets the discharge boundary conditions, it further determines whether a manual instruction to terminate discharge has been received. If no manual instruction to terminate discharge has been received, the process returns to step 2) and the vehicle continues to discharge. If a manual instruction to terminate discharge has been received, the battery management system sends a message to stop discharging, the charge and discharge interface switch K1 is disconnected, and the meter indicates that discharge has stopped. The specific process is shown in Figure 4.

[0034] Among them, the external discharge boundary conditions include:

[0035] ①The battery management system detects the charging gun in place signal (PP signal);

[0036] ②Battery capacity ≥ 30%;

[0037] ③The minimum voltage of a single cell is ≥3.2V;

[0038] ④No battery failure;

[0039] ⑤The battery management system BMS continues to receive V2X command messages;

[0040] If any of the above conditions are not met, the discharge state cannot be entered or the current discharge state cannot be stopped.

[0041] Vehicle Example:

[0042] A vehicle embodiment of the present invention includes a device for discharging the vehicle's power to the outside. This device is consistent with the device for discharging the vehicle's power to the outside described in the embodiment of the device for discharging the vehicle's power to the outside, and similarly achieves discharging the vehicle's power to the outside by reusing the inverter in the motor controller. The structure, operating principle, and corresponding effects of the device for discharging the vehicle's power to the outside have been described in detail in the embodiment of the device for discharging the vehicle's power to the outside, and will not be repeated in this embodiment.

[0043] While specific embodiments have been described above, the present invention is not limited to the described embodiments. The fundamental concept of the present invention lies in the aforementioned basic scheme. Based on the teachings of the present invention, those skilled in the art can devise various variations of models, formulas, and parameters without inventive effort. Changes, modifications, substitutions, and variations to the embodiments without departing from the principles and spirit of the present invention remain within the scope of protection of the present invention.

Claims

1. A device for discharging power from a vehicle, comprising a battery and a discharge interface, characterized in that: It also includes a switching switch unit and an inverter module in a motor controller; the DC end of the inverter module is connected to the battery, the AC end of the inverter module is connected to the first end of the switching switch unit, the second end of the switching switch unit is connected to the discharge interface, and the third end of the switching switch unit is used to connect the drive motor on the vehicle. The switching switch unit is used to make the inverter module and the discharge interface conductive when the vehicle meets the external discharge conditions, and is also used to make the inverter module and the drive motor conductive when the vehicle is in a driving state.

2. The vehicle discharge device according to claim 1, characterized in that: The switching switch unit includes a motor switch and a discharge interface switch, wherein one end of the motor switch and the discharge interface switch are connected to serve as the first end of the switching switch unit, the other end of the motor switch serves as the third end of the switching switch unit, and the other end of the discharge interface switch serves as the second end of the switching switch unit; and when the motor switch is disconnected and the discharge interface switch is closed, the inverter module and the discharge interface are connected; when the discharge interface switch is disconnected and the motor switch is closed, the inverter module and the drive motor are connected.

3. The vehicle discharge device according to claim 1, characterized in that: The discharge interface is multiplexed with the charging interface on the vehicle.

4. The vehicle discharge device according to claim 1 or 2, characterized in that: It also includes a meter, which is used to change the working state of the switching switch unit through the switch drive controller of the switching switch unit according to the user's mode selection instruction; the mode includes: external discharge mode.

5. The vehicle discharge device according to claim 1, characterized in that: The external discharge conditions include: detecting that the battery is plugged in, the user selecting the external discharge mode, and the battery meeting the external discharge boundary conditions.

6. The vehicle discharge device according to claim 5, characterized in that: The boundary conditions for external discharge include: detecting the charging gun in place signal; the battery capacity is greater than the capacity setting value; the lowest voltage of the battery's single cell is greater than or equal to the battery voltage setting value; there is no battery failure; and the battery management system continues to receive V2X command messages.

7. The vehicle discharge device according to claim 5, characterized in that: When the switching unit is in a state of conducting between the inverter module and the discharge interface, if any external discharge boundary condition is not satisfied, the switching unit is made to disconnect the conduction state between the inverter module and the discharge interface.

8. A vehicle, comprising a device for discharging the vehicle externally, the device comprising a battery and a discharge interface, characterized in that: The device for discharging the vehicle to the outside also includes a switching switch unit and an inverter module in a motor controller; the DC end of the inverter module is connected to the battery, the AC end of the inverter module is connected to the first end of the switching switch unit, the second end of the switching switch unit is connected to the discharge interface, and the third end of the switching switch unit is connected to the drive motor on the vehicle. The switching switch unit is used to connect the inverter module and the discharge interface when the vehicle meets the conditions for external discharge, and is also used to connect the inverter module and the drive motor when the vehicle is in a driving state.

9. The vehicle according to claim 8, characterized in that The switching switch unit includes a motor switch and a discharge interface switch, wherein one end of the motor switch and the discharge interface switch are connected to serve as the first end of the switching switch unit, the other end of the motor switch serves as the third end of the switching switch unit, and the other end of the discharge interface switch serves as the second end of the switching switch unit; and when the motor switch is disconnected and the discharge interface switch is closed, the inverter module and the discharge interface are connected; when the discharge interface switch is disconnected and the motor switch is closed, the inverter module and the drive motor are connected.

10. The vehicle according to claim 8, characterized in that The discharge interface is multiplexed with the charging interface on the vehicle.

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