A method for avoiding motor shaking caused by active power-off during driving of an electric vehicle

Abstract

This invention discloses a method to avoid motor vibration caused by actively shutting down an electric vehicle during driving, comprising: S1: The vehicle control unit (VCU) collects the status of the high-voltage relay, motor operating mode information, and the current operation information of the vehicle; S2: When the vehicle is in motion, the power-down button is pressed; S3: The high voltage is not shut down, the high-voltage relay remains closed, and the motor output torque is removed; S4: When the motor speed drops to 0 rpm and stabilizes, the high-voltage relay is disconnected, and the high voltage is shut down; S5: After the vehicle comes to a complete stop and the high-voltage relay is disconnected, even if the motor enters a three-phase short circuit state, it will not cause vehicle vibration. This invention, by pressing the power-down button, keeps the high voltage of the vehicle closed, the motor output torque is removed, and the high-voltage relay is disconnected only after the vehicle speed drops to 0 rpm and stabilizes. Even if the motor enters a three-phase short circuit state, it will not cause vehicle vibration, fundamentally solving the problem of motor vibration caused by actively shutting down the vehicle during driving.

Description

Technical Field

[0001] This invention belongs to the field of pure electric vehicle technology, and specifically relates to a method for avoiding motor vibration when actively de-energized during electric vehicle operation. Background Technology

[0002] Currently, new energy sources mainly include pure electric, hybrid, and plug-in hybrid electric vehicles.

[0003] In new energy pure electric vehicles, the sole power source is the drive motor. During operation, there is a certain probability of system failure, requiring the driver to immediately disconnect the power and pull the vehicle over to the side of the road. Currently, the standard solutions for system failures in all pure electric vehicles on the market include... Figure 1 As shown, the driver needs to press the power button to turn off the high voltage of the vehicle. When the vehicle suddenly loses power, the motor will enter the insulation detection state on the AC side. At this time, the motor enters a three-phase short circuit state, and the generated short circuit current will do work, causing the vehicle to shake, which brings a bad driving experience to the driver. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a method to avoid motor vibration caused by actively shutting down the electric vehicle during driving. By modifying the vehicle control strategy, the high-voltage shutdown process during driving is changed as follows: after pressing the power-down button, the vehicle does not shut down the high voltage; the high-voltage relay remains closed, and the motor output torque is removed. The high-voltage relay is then disconnected once the vehicle speed drops to 0 rpm and stabilizes. At this point, the vehicle has come to a complete stop, and even if the motor enters a three-phase short circuit state, it will not cause vehicle vibration. Through this modification, since high voltage is not applied during driving, the motor does not enter a three-phase short circuit state, preventing severe vehicle vibration. This fundamentally solves the problem of motor vibration caused by actively shutting down the electric vehicle during driving. Furthermore, by removing the motor output torque, it achieves the same performance effect as before the modification and avoids other malfunctions caused by the motor continuing to output torque during a fault.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A method is provided to avoid motor vibration during active power-off of an electric vehicle, the method comprising the following steps:

[0007] S1: The vehicle control unit (VCU) collects information on the status of high-voltage relays, motor operating mode, and the current operation information of the vehicle.

[0008] S2: The vehicle controller (VCU) determines the current vehicle status based on the collected high-voltage relay status and motor operating mode information. When the vehicle is in motion, press the power-off button.

[0009] S3: The vehicle controller VCU determines whether the vehicle is currently under high voltage based on the status of the high voltage relay. If the high voltage relay is in the closed state and the vehicle is not under high voltage, the high voltage relay remains in the closed state, and the motor output torque is removed.

[0010] S4: The vehicle controller (VCU) collects the real-time speed of the motor. When the real-time speed of the motor drops to 0pkh and stabilizes, the high-voltage relay is disconnected, and the high voltage of the vehicle is reduced.

[0011] S5: After the vehicle comes to a complete stop and the high-voltage relay is disconnected, the vehicle will not vibrate even if the motor enters a three-phase short circuit state.

[0012] To solve its technical problem, the present invention further adopts the following technical solution:

[0013] Furthermore, in step S1, when the vehicle controller (VCU) detects that the high-voltage relay is in the high-voltage state or the motor is in the output torque state, then step S2 is entered; otherwise, if the vehicle is not in the process of driving, step S1 is executed repeatedly.

[0014] Furthermore, in step S2, when the vehicle controller VCU determines that the vehicle is in driving mode based on the high voltage status of the high voltage relay or the output torque status of the motor, the process proceeds to step S3 when the power-off button is pressed.

[0015] Furthermore, in steps S3 and S4, the vehicle controller VCU collects information on the status of the high-voltage relay and the operating mode of the motor through the CAN communication bus, and the vehicle controller VCU collects the current operating information of the vehicle through the hard-wired I / O port.

[0016] Furthermore, the actuation information includes gear position signal, brake pedal signal, motor speed signal, and accelerator pedal opening signal.

[0017] Furthermore, in step S4, the vehicle control unit (VCU) acquires the vehicle stability control signal until it obtains the vehicle stability signal. After the vehicle comes to a complete stop, the VCU sends a high-voltage command to the high-voltage relay, and the high-voltage relay performs the high-voltage action.

[0018] Furthermore, if the high-voltage relay is in the open state, it indicates that the vehicle is not under high voltage, and the process ends directly; if the motor operating mode information shows that the motor is not driven, it indicates that the motor is in a non-driven state, and the process ends directly.

[0019] Furthermore, the method for avoiding motor vibration during electric vehicle operation is applicable to at least one of pure electric vehicles, hybrid electric vehicles, and plug-in hybrid electric vehicles.

[0020] The beneficial effects of this invention are:

[0021] The method of this invention consists of five steps: First, the vehicle control unit (VCU) collects the status of the high-voltage relay, the motor operating mode information, and the current operation information of the vehicle; Second, the VCU determines the current vehicle status based on the collected high-voltage relay status and motor operating mode information. When the vehicle is in motion, the power-off button is pressed; Third, the VCU determines whether the vehicle is currently under high voltage based on the high-voltage relay status. If the high-voltage relay is closed, the vehicle does not de-energize; if the high-voltage relay remains closed, the motor output torque is removed; Fourth, the VCU collects the real-time motor speed. When the real-time motor speed drops to 0 rpm and stabilizes, the high-voltage relay is disconnected, and the vehicle de-energizes; Fifth, the vehicle comes to a complete stop, and the high-voltage relay is disconnected. After the device is installed, even if the motor enters a three-phase short circuit state, it will not cause vehicle vibration. By modifying the vehicle control strategy, the high-voltage process during driving is changed to: after pressing the power-down button, the vehicle does not lower the high voltage, the high-voltage relay remains closed, the motor output torque is removed, and the high-voltage relay is disconnected after the vehicle speed drops to 0pkh and stabilizes. At this time, the vehicle has stopped, and even if the motor enters a three-phase short circuit state, it will not cause vehicle vibration. Through the above modification, since the high voltage is not lowered during driving, the motor does not fall into a three-phase short circuit state, and the problem of severe vehicle vibration will not occur. This fundamentally solves the problem of motor vibration when actively powered down during electric vehicle driving. At the same time, by removing the motor output torque, it has the same performance effect as before the modification, and will not cause other fault problems due to the motor continuing to output torque during a fault.

[0022] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0023] Figure 1 This is a conventional solution for pure electric vehicles experiencing system failures during operation, as described in this invention.

[0024] Figure 2 This is a flowchart illustrating a method for avoiding motor vibration during active power-off operation of an electric vehicle, as described in this invention. Detailed Implementation

[0025] The following specific embodiments illustrate the detailed implementation of the present invention. Those skilled in the art can easily understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented in other different ways, that is, different modifications and changes can be made without departing from the scope disclosed in the present invention.

[0026] Example:

[0027] This embodiment provides a method to avoid motor vibration during active power-off operation of an electric vehicle, such as... Figure 2 As shown, it includes the following steps:

[0028] The first step is for the vehicle control unit (VCU) to collect information on the status of the high-voltage relays, the motor operating mode, and the current operating information of the vehicle.

[0029] The second step is for the vehicle controller (VCU) to determine the current vehicle status based on the collected high-voltage relay status and motor operating mode information. When the vehicle is in motion, the power-off button is pressed.

[0030] Third, the vehicle controller (VCU) determines whether the vehicle is currently under high voltage based on the status of the high voltage relay. If the high voltage relay is closed and the vehicle is not under high voltage, the high voltage relay remains closed, and the motor output torque is removed.

[0031] The fourth step involves the vehicle controller (VCU) collecting the real-time speed of the motor. Once the real-time speed of the motor drops to 0 rpm and stabilizes, the high-voltage relay is disconnected, and the high voltage of the entire vehicle is reduced.

[0032] Fifth, after the vehicle comes to a complete stop and the high-voltage relay is disconnected, even if the motor enters a three-phase short circuit state, it will not cause the vehicle to shake.

[0033] In this embodiment, further speaking, in step S1, when the vehicle controller (VCU) detects that the high-voltage relay is in a high-voltage state or the motor is in an output torque state, then step S2 is entered; otherwise, if the vehicle is not in the process of driving, step S1 is executed repeatedly.

[0034] In this embodiment, further speaking, in step S2, when the vehicle controller VCU determines that the vehicle is in driving state based on the high voltage status of the high voltage relay or the output torque status of the motor, and when the power-off button is pressed, the process proceeds to step S3.

[0035] In this embodiment, further, in steps S3 and S4, the vehicle controller VCU collects the status of the high-voltage relay and the motor operating mode information through the CAN communication bus, and the vehicle controller VCU collects the current operating information of the vehicle through the hard-wired I / O port.

[0036] In the above embodiments, the actuation information further includes gear position signal, brake pedal signal, motor speed signal, and accelerator pedal opening signal.

[0037] In this embodiment, further speaking, in step S4, the vehicle control unit (VCU) acquires the vehicle stability control signal until the vehicle stability signal is obtained. After the vehicle comes to a complete stop, the VCU sends a high-voltage command to the high-voltage relay, and the high-voltage relay performs the high-voltage action.

[0038] In the above embodiments, further speaking, if the high-voltage relay is in the open state, it means that the vehicle is not connected to high voltage, and the process ends directly; if the motor working mode information shows that the motor is not driven, it means that the motor is in a non-driven state, and the process ends directly.

[0039] In this embodiment, the method for avoiding motor vibration during electric vehicle operation is applied to at least one of pure electric vehicles, hybrid electric vehicles, and plug-in hybrid electric vehicles.

[0040] The working process and working principle of this invention are as follows:

[0041] First, while the vehicle is in motion, press the power-off button. Specifically, while the vehicle is in motion, the vehicle controller (VCU) collects the status of the high-voltage relay, the motor operating mode information, and the current operating information of the vehicle. The VCU determines the current vehicle status based on the collected high-voltage relay status and motor operating mode information. When the vehicle is in motion, press the power-off button.

[0042] Then, if the vehicle is not under high voltage, the high voltage relay remains closed, and the motor output torque is removed. Specifically, the vehicle controller (VCU) determines whether the vehicle is under high voltage based on the state of the high voltage relay. If the high voltage relay is closed, and the vehicle is not under high voltage, the high voltage relay remains closed, and the motor output torque is removed.

[0043] Next, the high-voltage relay is disconnected once the vehicle speed drops to 0 pkh and stabilizes. Specifically, the vehicle controller (VCU) collects the real-time motor speed, and once the real-time motor speed drops to 0 pkh and stabilizes, the high-voltage relay is disconnected, and the high voltage of the entire vehicle is reduced.

[0044] Finally, since the vehicle has come to a complete stop at this point, even if the motor enters a three-phase short circuit state, it will not cause the vehicle to vibrate; specifically, after the vehicle has come to a complete stop and the high-voltage relay has been disconnected, even if the motor enters a three-phase short circuit state, it will not cause the vehicle to vibrate.

[0045] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure made using the content of the present invention specification and drawings, or directly or indirectly applied to other related technical fields, is similarly included within the patent protection scope of the present invention.

Claims

1. A method for avoiding motor vibration during active power-off operation of an electric vehicle, characterized in that: The method for avoiding motor vibration during active power-off operation of an electric vehicle includes the following steps: S1: The vehicle control unit (VCU) collects information on the status of high-voltage relays, motor operating mode, and the current operation information of the vehicle. S2: The vehicle controller (VCU) determines the current vehicle status based on the collected high-voltage relay status and motor operating mode information. When the vehicle is in motion, press the power-off button. S3: The vehicle controller VCU determines whether the vehicle is currently under high voltage based on the status of the high voltage relay. If the high voltage relay is in the closed state and the vehicle is not under high voltage, the high voltage relay remains in the closed state, and the motor output torque is removed. S4: The vehicle controller VCU collects the real-time speed of the motor. When the real-time speed of the motor drops to 0pkh and stabilizes, the high-voltage relay is disconnected, and the high voltage of the whole vehicle is reduced. S5: After the vehicle comes to a complete stop and the high-voltage relay is disconnected, the vehicle will not vibrate even if the motor enters a three-phase short circuit state. In step S1, when the vehicle controller (VCU) detects that the high-voltage relay is in the high-voltage state or the motor is in the output torque state, then proceed to step S2; otherwise, if the vehicle is not in the process of driving, step S1 is executed repeatedly. In step S2, when the vehicle controller VCU determines that the vehicle is in driving mode based on the high voltage status of the high voltage relay or the output torque status of the motor, and when the power-off button is pressed, the process proceeds to step S3. In steps S3 and S4, the vehicle controller VCU collects high-voltage relay status and motor operating mode information through the CAN communication bus, and the vehicle controller VCU collects the current operation information of the vehicle through hard-wired I / O ports. The actuation information includes gear position signal, brake pedal signal, motor speed signal, and accelerator pedal opening signal; In step S4, the vehicle control unit (VCU) acquires the vehicle stability control signal until it obtains the vehicle stability signal. After the vehicle comes to a complete stop, the VCU sends a high-voltage reduction command to the high-voltage relay, and the high-voltage relay performs the high-voltage reduction action. If the high-voltage relay is in the open state, it means that the vehicle is not connected to high voltage, and the process ends directly. If the motor operating mode information shows that the motor is not driven, it means that the motor is in a non-driven state, and the process will end directly.

2. The method for avoiding motor vibration during active power-off operation of an electric vehicle according to claim 1, characterized in that: The method for avoiding motor vibration during electric vehicle operation is applicable to at least one of pure electric vehicles, hybrid electric vehicles, and plug-in hybrid electric vehicles.

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