CN-122008900-A - High-voltage monitoring method for driving motor of electric automobile

CN122008900ACN 122008900 ACN122008900 ACN 122008900ACN-122008900-A

Abstract

The invention discloses a high-voltage monitoring method for a driving motor of an electric automobile, which comprises the steps of S1, obtaining a communication state of a motor control system, an operation mode of the motor control system and an operation state of a main contactor, S2, starting periodic staged high-voltage monitoring of the driving motor when the motor control system is in any one state of a high-voltage standby mode, the main contactor is disconnected and communication faults, and starting a readback channel of a GDU (graphic display unit) in stages to read feedback values of 6 driving bridge arms in a set period and judge the on-off states of all driving bridge arms according to the obtained feedback values when the high-voltage monitoring is performed, determining that the high-voltage standby mode is normal when the feedback values of the 6 driving bridge arms are all zero, and sending a request for requesting to enter the high-voltage standby mode to an MCU (micro controller) when the feedback values of the 6 driving bridge arms are not all zero.

Inventors

CAO XU
ZU CONGLIN
GONG WEILUN
ZHANG XIANGKUI
ZHAO QI
ZHOU YAOHONG
MOU CHUAN

Assignees

重庆青山工业有限责任公司

Dates

Publication Date: 20260512
Application Date: 20260325

Claims (5)

1. A high-voltage monitoring method for a driving motor of an electric automobile is characterized by comprising the steps of S1, obtaining a communication state of a motor control system, an operation mode of the motor control system and an operation state of a main contactor, S2, starting periodic staged high-voltage monitoring of the driving motor when the motor control system is in any one state of a high-voltage standby mode, the main contactor is disconnected and communication faults, and starting a readback channel of a GDU in stages to read feedback values of 6 driving bridge arms in a set period during the high-voltage monitoring, judging the switching states of all driving bridge arms according to the obtained feedback values, determining that the high-voltage standby mode is normal when the feedback values of the 6 driving bridge arms are all zero, and sending a request for requesting to enter the high-voltage standby mode to an MCU if the feedback values of the 6 driving bridge arms are not all zero.
2. The method according to claim 1, wherein in S2, when the motor control system is switched from the torque mode to the high-voltage standby mode or from the rotation speed mode to the high-voltage standby mode, the motor control system starts the high-voltage monitoring of the driving motor.
3. The method for monitoring the high voltage of the driving motor of the electric vehicle according to claim 1 or 2, wherein in S2, when the main positive relay or the main negative relay of the high voltage battery pack is turned off, it is determined that the main contactor is turned off.
4. The method for monitoring the high voltage of the driving motor of the electric automobile according to claim 3, wherein in S2, when the communication between the ECU and the can bus is in an off-line state or repaired for more than a certain time after the last off-line state, the corresponding data is not received any more than once, or the message is sent out to end to check the error, and after the number of times of check errors reaches the set number of times, the communication fault diagnosis is sent out.
5. The method for monitoring the high voltage of the driving motor of the electric automobile according to claim 4, wherein a delay period is set before the periodic staged high voltage monitoring of the driving motor is started, and then a readback channel is opened to read the feedback value of the driving bridge arm.

Description

High-voltage monitoring method for driving motor of electric automobile Technical Field The invention relates to the field of new energy automobile electric drive systems, in particular to a high-voltage monitoring method for a driving motor of an electric automobile. Background The driving motor control system is used as a key core component of the new energy automobile and is mainly used for controlling the magnitude and the direction of the output torque of the driving motor. The driving motor system not only determines the dynamic performance parameters of the whole vehicle, but also is closely related to the safe operation of the vehicle. Particularly, in recent years, with the increase of permeability of new energy automobiles and the innovation and application of various new technologies, the new energy automobiles have the development trends of increasing the requirements of wide speed regulation range, high power density, light weight, high efficiency, high safety, low cost and the like of motors, digitizing, integrating, high voltage and the like, and the driving motor control system has the increasingly remarkable safety risks of accidents such as vehicle runaway, personal injury and the like caused by abnormal functions and faults. Therefore, functional safety of the drive motor control system, in particular high voltage monitoring, is particularly important. At present, in order to ensure the safety of a motor control system, insulation resistance signals, connection resistance signals and relays in a control circuit are monitored in real time after the motor control circuit is monitored, so that the health monitoring of a driving motor is realized. However, in practical application, when the driving power device is in a working condition that the driving power device needs to be turned off and the high-voltage output is in a high-voltage standby state, the driving power device needs to be prevented from being in a non-high-voltage standby state in the state, and the high-voltage function is abnormal and fails. Therefore, the state of the driving power device needs to be monitored in real time, and the high-voltage abnormal function is avoided. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to solve the problems that the existing electric automobile lacks a method for monitoring the high voltage of the driving motor in real time and cannot respond and judge the abnormality of the high voltage state quickly, and provides a method for monitoring the high voltage of the driving motor of the electric automobile, which can monitor the high voltage state of the driving motor and avoid the abnormality and the fault of the high voltage function. In order to solve the technical problems, the technical scheme adopted by the invention is as follows: A high-voltage monitoring method for a driving motor of an electric automobile comprises the steps of S1, obtaining a communication state of a motor control system, an operation mode of the motor control system and an operation state of a main contactor, S2, starting periodic staged high-voltage monitoring of the driving motor when the motor control system is in any one of a high-voltage standby mode, the main contactor is disconnected and communication faults, and starting a readback channel of a GDU in stages to read feedback values of 6 driving bridge arms in a set period when the driving motor is monitored at high voltage, judging the switching states of all driving bridge arms according to the obtained feedback values, determining that the high-voltage standby mode is normal when the feedback values of the 6 driving bridge arms are all zero, and sending a request for requesting to enter the high-voltage standby mode to an MCU if the feedback values of the 6 driving bridge arms are not all zero. After the monitoring method is adopted, feedback values of 6 driving bridge arms in a motor control system of the automobile in a communication fault or main contactor disconnection or high-voltage standby mode can be continuously monitored, so that whether the high-voltage standby mode is in a normal state or not is determined, high-voltage abnormal information is sent when the high-voltage standby mode is abnormal, and meanwhile, a request for entering the high-voltage standby mode is sent, so that the situation that the electric automobile is abnormal and faulty in high voltage when the automobile is in the high-voltage standby mode is effectively avoided, and the high-voltage standby state is continuously monitored. Before high-voltage monitoring, the high-voltage monitoring condition is judged, so that the safety of high-voltage monitoring can be ensured. Further, in S2, when the motor control system is switched from the torque mode to the high-voltage standby mode or from the rotation speed mode to the high-voltage standby mode, the motor control system starts high-voltage monitoring of the driving motor. Before hi