Abstract: Aiming at current sensor fault affecting the normal operation of the electric drive system, a new fault detection and fault-tolerant control method of multi-current sensor was proposed. Firstly, based on the vector control principle of induction motor, the judgment functions Z_i and P_i were introduced and hysteresis comparator was set up. A fault detection method for single and multiple current sensors was designed based on the output results of the comparator. Then, according to the space vector pulse width modulation(SVPWM)principle and the relationship between DC bus voltage and sector voltage, the fault tolerant control of the fault phase current sensor was carried out. Finally, the method were verified and comparative analysis by MATLAB software was performed. The results show that the proposed method is feasible for the multi-sensor fault-tolerant control of asynchronous motor. It has strong localization ability and high accuracy for fault phases, and it is superior to the traditional sliding mode observer scheme and the ideal motor model with extended Kalman filter scheme in terms of three-phase current reconstruction. The fault tolerant reduction rate after reconstruction reaches 95.4% of the normal working condition, and it has better control effect.

Key words: asynchronous motor, current sensor fault, fault-tolerant control, fault factors, hysteresis comparator