Self-healing method for electric vehicle drive motor overcurrent fault

Abstract

The invention provides a self-healing method for the over-current fault of a drive motor of an electric vehicle. The method comprises the steps that the three-phase currents of a drive motor are collected to be compared with a set current protection value; if the three-phase currents are less than the current protection value, a vehicle runs normally and if the current of any phase is greater than the current protection value, the number of times N of collection and a current pre-warning value are set; when the currents of any phase collected for consecutive N times are all greater than the current pre-warning value, it is judged that the drive motor has the over-current fault and a controller gives a fault marking location and a drive motor control system stops working; otherwise, the vehicle runs normally and the three-phase current collection periods are repeated; when the rotating speed of the drive motor is not greater than the allowable self-recovery rotating speed of the drive motor system and the prescribed moment and rotating speed instructions are zero, the controller removes the fault marking location and responds to a vehicle control instruction normally, and the drive motor control system returns to work. The method enables a drive motor of a vehicle to be capable of recovering from the over-current fault by itself and run continuously, prevents power loss of the vehicle and thus guarantees the running safety of the vehicle.

Description

technical field [0001] The invention relates to a self-healing method for an overcurrent fault of a drive motor of an electric vehicle. Background technique [0002] During the driving process of the electric vehicle, the output current of the motor system changes according to the change of the driving conditions of the whole vehicle. When the driver steps on the accelerator to accelerate or start on a slope, especially when the vehicle is fully loaded or overloaded, the drive motor needs to output a large torque. At this time, the motor system will generate a large three-phase current, which is likely to exceed the controller's capacity. current protection value, so as to report an overcurrent fault and cause the vehicle to lose power and stop. In the process of the vehicle going uphill or driving at high speed, once this fault occurs, there will be a great safety hazard. In addition, the cause of the overcurrent fault of the drive motor is not only stepping on the accele...

AI Technical Summary

Problems solved by technology

When the driver steps on the accelerator to accelerate or start on a hill, especially when the vehicle is fully loaded or overloaded, the drive motor needs to output a large torque. At this time, the motor system will generate a large three-phase current, which may exceed the controller's limit. Current protection value, thus reporting an overcurrent fault and causing the vehicle to lose power and stop

In the process of the vehicle going uphill or at high speed, once this fault occurs, there will be a great potential safety hazard

In addition, the cause of the overcurrent fault of the driving motor is not only when the accelerator is stepped on when the vehicle is running uphill, fully loaded, or overloaded. When the vehicle operating environment deteriorates and the controller hardware is subjected to electromagnetic interference, a false current signal may also appear. Overshoot , leading to misjudgment of overcurrent fault

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