Control Method and Device for Active Short-Circuit Drive of Electric Vehicle

Abstract

A control method for active short-circuit driving of an electric vehicle, comprising: a step in which a PDU controller synchronously outputs an active short-circuit safety state enable signal and an off signal of a PDU relay; a step in which the motor control system is logged out from the boost charging mode by the off signal of the PDU relay; and a step in which, after the motor control system is logged out from the boost charging mode, the motor control system is caused to enter the active short-circuit safety state by the active short-circuit safety state enable signal. Further, it relates to a control device for active short-circuit driving of an electric vehicle. In actual application, it solves the risk that the motor controller accidentally enters the active short-circuit safety state due to a failure in the boost charging mode and damages the drive module.

Description

Technical Field

[0001] This application claims the priority of a Chinese patent application with an application number of 202210648061.3, filed on June 8, 2022.

[0002] This application belongs to the field of electric vehicles, and particularly relates to a control method and device for active short-circuit driving of electric vehicles.

Background Art

[0003] With the rapid development of modern electric vehicle technology, 800V pure electric vehicles are a new trend in the current electric vehicle market. Conventional electric vehicles in the market are often 400V, and the charging piles, which are auxiliary facilities, are generally of 400V specifications. To promote the market application of the 800V platform, the 800V drive platform is equipped with many Boost (step-up) charging functions to solve the battery charging problem. At the same time, to save costs, the drive mode and the Boost charging mode share the controller and the power module, and the motor coil is used as the charging inductance in the Boost charging mode. Under such a premise, the vehicle affects the control policy of the controller in three operating situations, namely the drive mode, the step-up charging mode, and the traction mode. This poses a new challenge to how the controller can achieve safe and reliable control in the three modes, especially when the controller cannot distinguish whether it is currently in the drive, step-up, or traction mode in case of a failure, and still take effective countermeasures. Also, to solve the charging problem, it is necessary to arrange a normal power distribution unit (PDU). Since this unit is a high-voltage unit, a PDU management module is required to ensure the reliability and safety of the PDU. Usually, the controller manages several solenoid valves and monitors the voltage for each node of the high-voltage path.

[0004] The 800V platform still belongs to new technologies in the market. The active short-circuit control solution in the 400V platform cannot currently be compatible with the boost charging mode. The fault operation situation cannot solve the problem that the system enters the active short-circuit state, i.e., ASC, in the boost charging mode, which brings a risk of failure to the high-voltage drive module, and there is no clear solution in the current market.

Summary of the Invention

Problems to be Solved by the Invention

[0005] This application provides a control method and device for active short-circuit drive for electric vehicles, aiming to solve the problem that the motor controller accidentally enters the active short-circuit safety state due to a fault in the boost charging mode, risking damage to the drive module.

Means for Solving the Problems

[0006] Regarding the above problems, the technical solutions adopted in this application are as follows. The control method for active short-circuit drive for electric vehicles includes the step that the PDU controller synchronously outputs an active short-circuit safety state enable signal and an off signal of the PDU relay, when the vehicle fails in the boost charging mode, the step of logging out the motor control system from the boost charging mode by the off signal of the PDU relay, after the motor control system logs out from the boost charging mode, the step of enabling the motor control system to enter the active short-circuit safety state by the active short-circuit safety state enable signal.

[0007] In one embodiment, the active short-circuit safety state enable signal is transmitted with a delay via a delay circuit after the off signal of the PDU relay.

[0008] In one embodiment, when the vehicle is in a normal operating condition in the boost charging mode, the control method further includes a step in which the PDU controller outputs a PDU relay activation signal and synchronously outputs it to the motor controller, and locks the output of the active short - circuit safety state.

[0009] In one embodiment, when the vehicle fails in the driving mode, the control method includes a step of triggering the motor control system based on the functional safety management signal to enter the active short - circuit safety state.

[0010] In one embodiment, when the vehicle is in the driving mode under normal operating conditions, the control method includes the step of synchronously outputting the off signal of the PDU relay output from the PDU controller to the motor controller, and the step of determining whether the motor control system needs to enter the active short - circuit safety state based on the bus voltage of the motor controller, and if so, the step of the motor control system entering the active short - circuit safety state based on the active short - circuit safety state enable signal.

[0011] In one embodiment, when the connector connection between the motor controller and the PDU controller is uncertain, the control method includes the step of determining whether the motor control system needs to enter the active short - circuit safety state based on the bus voltage of the motor controller and the current vehicle mode, and if so, the step of the motor control system entering the active short - circuit safety state based on the active short - circuit safety state enable signal.

[0012] In one embodiment, when the vehicle is in the traction mode, the control method includes the step of synchronously outputting the off signal of the PDU relay output from the PDU controller to the motor controller, and the step of determining whether the motor control system needs to enter the active short - circuit safety state based on the bus voltage of the motor controller. If so, the motor control system further includes the step of entering the active short - circuit safety state based on the active short - circuit safety state enable signal.

[0013] And, the control device for active short - circuit drive of an electric vehicle is a PDU management unit for synchronously outputting an active short - circuit safety state enable signal and an off signal of the PDU relay, where the off signal of the PDU relay is a PDU management unit that synchronously outputs to the motor controller, a motor control unit for logging out the motor control system from the boost charging mode based on the off signal of the PDU relay, an active short - circuit safety state trigger unit for causing the motor control system to enter the active short - circuit safety state based on the active short - circuit safety state enable signal after the motor control system logs out from the boost charging mode.

[0014] In one embodiment, the control device further includes a signal delay unit for causing the motor control system to enter the active short - circuit safety state based on the active short - circuit safety state enable signal after the motor control system logs out from the boost charging mode by transmitting the active short - circuit safety state enable signal later than the off signal of the PDU relay.

[0015] In one embodiment, the control device further includes an active short - circuit safety state lock unit for locking the output of the active short - circuit safety state when the PDU management unit outputs a PDU relay activation signal.

[0016] In one embodiment, the control device further includes a functional safety management unit for transmitting a functional safety management signal when the vehicle fails in the driving mode, The active short - circuit safety state trigger unit is further used to trigger the motor control system based on the functional safety management signal to enter the active short - circuit safety state.

[0017] In one embodiment, the control device further includes a determination unit for determining whether the motor control system needs to enter the active short - circuit safety state based on the bus voltage of the motor controller when the vehicle is in the driving mode or traction mode under normal operating conditions.

[0018] In one embodiment, when the connector connection between the motor controller and the PDU controller is uncertain, the determination unit is further used to determine whether the motor control system needs to enter the active short - circuit safety state based on the bus voltage of the motor controller and the current vehicle mode.

[0019] The electric vehicle includes the above - mentioned control device for active short - circuit driving.

Advantages of the Invention

[0020] By adopting the above - mentioned technical solution, the present application endows it with the following functions. When the motor controller fails and wrongly enters the active short - circuit safety state (ASC) in the boost charging mode, the risk of damaging the drive module is solved. The over - voltage in the traction mode and the over - voltage in the boost charging mode are distinguished, so that the hardware enters the corresponding accurate protection mode. The implementation method is simple, avoiding the logical risk caused by complex circuit design, and the cost is relatively low.

[0021] Other features and advantages of the present application are described in the following specification, and are partially clear from the specification, or can be understood by implementing the present application. The objectives and other advantages of the present application can be realized and obtained by the structures pointed out in the specification, claims and drawings.

Brief Description of the Drawings

[0022] To more clearly explain the technical solutions in the embodiments of this application or the prior art, the following briefly introduces the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of this application. For those skilled in the art, based on these drawings, other drawings can be obtained without creative efforts.

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following refers to the drawings in the embodiments of this application and clearly and completely describes the technical solutions in the embodiments of this application. Obviously, the described embodiments are some embodiments of this application, not all embodiments.

[0024] Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of this application.

[0025] The control method for active short-circuit drive of an electric vehicle in the embodiment of this application is that the PDU controller synchronously outputs an active short-circuit safety state enable signal and an off signal of the PDU relay, where the off signal of the PDU relay output from the PDU controller synchronously outputs to the motor controller.

[0026] The control methods for different operating conditions are as follows.

[0027] 1. When the vehicle fails in the boost charging mode (when in an overvoltage state), The off signal of the PDU relay logs out the motor control system from the boost charging mode, After the motor control system logs out from the boost charging mode, the active short - circuit safety state enable signal is used to make the motor control system enter the active short - circuit safety state.

[0028] Second, when the vehicle is in the normal operating condition of the boost charging mode, The PDU controller outputs a PDU relay activation signal and synchronously outputs it to the motor controller to lock the output of the active short - circuit safety state.

[0029] Third, when the vehicle fails in the driving mode and an over - voltage state occurs, The motor control system is triggered based on the functional safety management signal to enter the active short - circuit safety state.

[0030] Fourth, when the vehicle is in the driving mode under normal operating conditions, The motor control system determines whether it is necessary to enter the active short - circuit safety state based on the bus voltage of the motor controller, If so, the motor control system enters the active short - circuit safety state based on the active short - circuit safety state enable signal.

[0031] Fifth, when the connector connection between the motor controller and the PDU controller is uncertain, The motor control system determines whether it is necessary to enter the active short - circuit safety state based on the bus voltage of the motor controller and the current vehicle mode, If so, the motor control system enters the active short - circuit safety state based on the active short - circuit safety state enable signal.

[0032] Sixth, when the vehicle is in the traction mode, The motor control system determines whether it is necessary to enter the active short - circuit safety state based on the bus voltage of the motor controller, If so, the motor control system enters the active short - circuit safety state based on the active short - circuit safety state enable signal.

[0033] As shown in the schematic diagram of the logic circuit in FIG. 1, it includes two circuits for executing the attachment state of the active short circuit. In the first circuit, when transmitting a fault signal, that is, a function fault signal, after passing through the insulation separation units S1 and S2, it directly triggers the active short circuit safety state execution signal, that is, the ASC_LS_EM signal. In the second circuit, it is selected to trigger the ASC_LS_EM signal by the logic tri-state strobe gate IC1. Since the output results of the above two circuits are consistent, the first logic OR gate is adopted to reduce the circuit complexity.

[0034] As shown in the schematic diagram of the signal output circuit in FIG. 2, the PDU management MCU (PDU management chip) of the PDU controller outputs the active short circuit safety state enable signal, that is, the PDU_ASC_EN signal, by the ASC enable signal control circuit. At the same time, the PDU charging control relay interface circuit outputs the off signal of the PDU relay of the charging control relay CB1, thereby realizing the synchronous output of the PDU_ASC_EN and the off signal of the PDU relay.

[0035] Referring to the schematic diagram of the logic circuit shown in FIG. 1, the specific logic of the above multiple operating conditions is as follows.

[0036] In the above operating condition 3, when a fault occurs in the drive mode and an overvoltage state occurs, the motor control system is triggered by the functional safety management signal to enter the active short circuit safety state. The functional safety management signal is that is, the SAFE STATE signal. Since the logic of the PDU_ASC_EN signal and the SAFE STATE signal is consistent, the second logic OR gate is adopted to reduce the circuit complexity.

[0037] In the above operating condition 2, the PDU controller outputs a PDU relay start signal. Here, the PDU relay start signal is a logic high level, and the logic high level is synchronously output to the motor controller. The motor controller operates normally. At this time, the PDU_ASC_EN signal and the SAFE STATE signal are not output. The logic tri-state strobe gate IC1 is in the off state, thereby locking the output in the active short-circuit safe state. In the above operating condition 1, when the vehicle fails in the boost charging mode, the PDU controller synchronously outputs the PDU_ASC_EN signal and the off signal of the PDU relay. The off signal of the PDU relay is at a logic low level and is synchronously output to the motor controller to log out the motor control system from the boost charging mode. The PDU_ASC_EN signal is transmitted later than the off signal of the PDU relay through a delay circuit. After passing through the insulation isolation unit S1, the logic tri-state strobe gate turns on, thereby triggering the ASC strobe by overvoltage in the boost charging mode, that is, triggering the ASC_LS_EM signal. Thereby ensuring that the motor control system does not enter the ASC state in the boost charging mode.

[0038] Among them, as shown in FIG. 1, the delay circuit is an RC circuit, which filters and provides a delay to the signal at the same time. The RC circuit includes a resistor R1, a resistor R2, and a capacitor C1. Here, both ends of R1 are connected between the PDU_ASC_EN signal and the second logic OR gate. The first end of R2 is connected between R1 and the PDU_ASC_EN signal, the second end of R2 is grounded, the first end of C1 is connected between R1 and the second logic OR gate, and the second end of C1 is connected to the second end of R2.

[0039] In the above operating conditions 4 and 6, when the vehicle is in the driving mode or the traction mode in the normal operating condition, the PDU controller outputs the off signal of the PDU relay, that is, a logic low level, and synchronously outputs it to the motor controller to determine whether the motor control system needs to enter the active short-circuit safe state based on the bus voltage of the motor controller.

[0040] In the above operation status 5, when the connector connection between the motor controller and the PDU controller is uncertain, at this time, the control port is arranged at a low level. When the vehicle is in a different mode, since the voltage threshold for entering the active short-circuit safety state is different, whether the motor control system needs to enter the active short-circuit safety state is controlled by the bus voltage of the motor controller and the current vehicle mode.

[0041] In the above operation status 4, 5, and 6, it is determined whether the motor control system needs to enter the active short-circuit safety state based on the bus voltage of the motor controller. Specifically, it is as follows. When the bus voltage of the motor controller exceeds the first threshold voltage in the driving mode, the motor control system is triggered to enter the active short-circuit safety state. When the bus voltage of the motor controller is higher than the set second threshold voltage in the traction mode, the motor control system is triggered to enter the active short-circuit safety state.

[0042] As shown in FIG. 1, VDC_S is the bus voltage of the motor controller. In a normal operation status, the logic tri-state strobe gate is off, and VDC_S cannot affect the ASC logic. After powering down on the low-voltage side in the traction operation status, the power supply is connected to the high-voltage side (in the control system of the in-vehicle drive motor, low voltage refers to an electronic unit or circuit powered by the vehicle's 12V or 24V battery, and high voltage is the power battery, which is usually an electronic module and unit powered by 380V - 800V. Since the two power supply systems cannot have a physical passage, the insulation separation units S1 and S2 realize the high-low voltage connection by means of magnetic coupling), when VDC_S is higher than the threshold, ASC can be triggered, that is, high-speed traction can trigger ASC, and the failure of the power module in the traction mode is avoided.

[0043] The embodiment of the present application further provides a control device for active short-circuit drive for an electric vehicle, and the control device includes a PDU management unit for synchronously outputting an active short-circuit safety state enable signal and an off signal of the PDU relay, A motor control unit for logging out a motor control system from a boost charging mode based on an off signal of a PDU relay, an active short - circuit safety state trigger unit for causing the motor control system to enter an active short - circuit safety state based on an active short - circuit safety state enable signal after the motor control system logs out from the boost charging mode, a signal delay unit for causing the motor control system to enter an active short - circuit safety state based on an active short - circuit safety state enable signal after the motor control system logs out from the boost charging mode by transmitting the active short - circuit safety state enable signal later than the off signal of the PDU relay, an active short - circuit safety state lock unit for locking the output of the active short - circuit safety state when the PDU management unit outputs a PDU relay activation signal, a functional safety management unit for transmitting a functional safety management signal when the vehicle fails in a driving mode, wherein the active short - circuit safety state trigger unit is further used to trigger the motor control system to enter an active short - circuit safety state based on the functional safety management signal output from the functional safety management unit, a determination unit for determining whether the motor control system needs to enter an active short - circuit safety state based on the bus voltage of the motor controller when the vehicle is in a driving mode or a traction mode in a normal operating situation, and the determination unit is further used to determine whether the motor control system needs to enter an active short - circuit safety state based on the bus voltage of the motor controller and the current vehicle mode when the connector connection between the motor controller and the PDU controller is uncertain, and includes:

[0044] The realization process of the functions and actions of the above - mentioned module units refers to the realization process of the corresponding steps in the control method for active short - circuit driving of an electric vehicle in the embodiment of the present application, and the description is omitted here.

[0045] The embodiment of the present application further provides an electric vehicle, which includes the control device for active short-circuit driving of the above embodiment.

[0046] What is described above is only a selectable embodiment of the present application, and does not impose any formal restrictions on the present application. Although the present application is disclosed as above in selectable embodiments, it is not limited thereto. Those skilled in the art, without departing from the technical solution of the present application, can make some changes or modifications using the technical content disclosed above to obtain equivalent embodiments of equivalent changes. However, as long as it does not depart from the content of the technical solution of the present application, any simple corrections, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application all belong to the scope of the technical solution of the present application.

Claims

1. The PDU controller outputs an active short - circuit safety state enable signal and an off signal of the PDU relay synchronously, When the vehicle fails in the boost charging mode, the off signal of the PDU relay is used to log out the motor control system from the boost charging mode, After the motor control system logs out from the boost charging mode, the active short - circuit safety state enable signal is used to put the motor control system into the active short - circuit safety state, including: A control method for active short - circuit drive of an electric vehicle.

2. The active short - circuit safety state enable signal is transmitted with a delay via a delay circuit after the off signal of the PDU relay, The control method for active short - circuit drive of an electric vehicle according to Claim 1.

3. When the vehicle is in a normal operating condition in the boost charging mode, the PDU controller outputs a PDU relay activation signal and synchronously outputs it to the motor controller, and locks the output of the active short - circuit safety state, When the vehicle fails in the drive mode, the motor control system is triggered based on the functional safety management signal to enter the active short - circuit safety state, The control method for active short - circuit drive of an electric vehicle according to Claim 1.

4. When the vehicle is in the drive mode in a normal operating condition, the control method includes: Synchronously outputting the off signal of the PDU relay output from the PDU controller to the motor controller, Judging whether it is necessary to put the motor control system into the active short - circuit safety state based on the bus voltage of the motor controller, If it is judged to be necessary, the motor control system further includes the step of entering the active short - circuit safety state based on the active short - circuit safety state enable signal. The control method for active short - circuit drive of an electric vehicle according to Claim 1.

5. When the connector connection between the motor controller and the PDU controller is uncertain, the control method includes: determining whether it is necessary to put the motor control system into an active short-circuit safety state based on the bus voltage of the motor controller and the current vehicle mode; if it is determined that it is necessary, the motor control system further includes a step of entering the active short-circuit safety state based on the active short-circuit safety state enable signal. The control method for active short-circuit driving of an electric vehicle according to claim 1.

6. When the vehicle is in the traction mode, the control method includes: synchronously outputting the off signal of the PDU relay output from the PDU controller to the motor controller; determining whether it is necessary to put the motor control system into an active short-circuit safety state based on the bus voltage of the motor controller; if it is determined that it is necessary, the motor control system further includes a step of entering the active short-circuit safety state based on the active short-circuit safety state enable signal. The control method for active short-circuit driving of an electric vehicle according to claim 1.

7. A PDU management unit for synchronously outputting an active short-circuit safety state enable signal and an off signal of the PDU relay, where the PDU management unit synchronously outputs the off signal of the PDU relay to the motor controller; a motor control unit for logging out the motor control system from the boost charging mode based on the off signal of the PDU relay; an active short-circuit safety state trigger unit for putting the motor control system into an active short-circuit safety state based on the active short-circuit safety state enable signal after the motor control system logs out from the boost charging mode. The control device for active short-circuit driving of an electric vehicle.

8. By transmitting the active short - circuit safety state enable signal after the off signal of the PDU relay, a signal delay unit is further included for putting the motor control system into the active short - circuit safety state based on the active short - circuit safety state enable signal after the motor control system logs out from the boost charging mode. The control device for active short - circuit drive of an electric vehicle according to claim 7.

9. When the PDU management unit outputs a PDU relay activation signal, it further includes an active short - circuit safety state lock unit for locking the output of the active short - circuit safety state. The control device for active short - circuit drive of an electric vehicle according to claim 7.

10. When the vehicle fails in the driving mode, it further includes a functional safety management unit for transmitting a functional safety management signal. The active short - circuit safety state trigger unit is further used to trigger the motor control system to enter the active short - circuit safety state based on the functional safety management signal. The control device for active short - circuit drive of an electric vehicle according to claim 7.

11. When the vehicle is in the driving mode or the traction mode under normal operating conditions, it further includes a judgment unit for judging whether it is necessary to put the motor control system into the active short - circuit safety state based on the bus voltage of the motor controller. The control device for active short - circuit drive of an electric vehicle according to claim 7.

12. When the connection between the motor controller and the PDU controller is uncertain, the judgment unit is further used to judge whether it is necessary to put the motor control system into the active short - circuit safety state based on the bus voltage of the motor controller and the current vehicle mode. The control device for active short - circuit drive of an electric vehicle according to claim 11.

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