Self-checking method and device for active short-circuit protection circuit of motor control system

Abstract

The present invention discloses a self-checking method and a device for the active short-circuit protection circuit of a motor control system. The self-checking method for the active short-circuit protection circuit comprises the steps of controlling a multi-phase bridge type circuit, wherein an upper half-bridge corresponding to a first-phase winding and a lower half-bridge corresponding to a second-phase winding are switched on, while all other phase windings are not switched on; sampling the current of each phase winding multiple times, and conducting the split-phase accumulation; if the current cumulative sum of the above two correspondingly switched-on phase windings meets an approximation condition and the current cumulative sum of all the other phase windings is approximately zero, conducting the next detection until all upper and lower half-bridges of the multi-phase bridge type circuit are already detected once; if the current cumulative sum of the above two correspondingly switched-on phase windings meets the approximation condition, passing the self-checking of the active short-circuit protection circuit. Based on the method and the device, circuit faults can be actively precluded. Therefore, the IGBT burnout condition of the motor and the controller of a finished automobile due to circuit faults can be prevented. Meanwhile, no external circuit is added, so that the cost is saved. The power-on time of the finished automobile is saved.

Description

technical field [0001] The invention relates to the field of electric vehicles, in particular to a self-inspection method and device for an active short-circuit protection circuit of a motor control system. Background technique [0002] During the driving process of electric vehicles, in order to avoid the sudden failure of the whole vehicle and make the whole vehicle go into safety mode, the motor control system in the power of the whole vehicle needs to carry out active short-circuit self-checking measures. The control method uses three-phase AC to control the motor to run stably under the torque loop and speed loop. The active short-circuit self-test process of the motor means that the three-phase upper bridge power switching device in the three-phase six-bridge circuit is turned off, and the three-phase lower bridge power switching device is turned off. Conduction, so that the three-phase windings inside the motor are short-circuited together, the drive motor is locked t...

AI Technical Summary

Problems solved by technology

[0004] The external hardware circuit can quickly enter the active short circuit, but there is no power-on self-check whether the active short circuit is normal, so even with this external auxiliary active short circuit hardware, the motor will still work after a strong power is applied, which may cause the motor to burn out or the IGBT Burning and other phenomena, resulting in vehicle safety problems

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