Active fault-tolerant control of induction motor drives in EV and HEV against sensor failures using a fuzzy decision system

This paper describes an active fault-tolerant control system for a high performance induction motor drive that propels an electrical vehicle (EV) or a hybrid one (HEV). The proposed system adaptively reorganizes itself in the event of sensor loss or sensor recovery to sustain the best control performance given the complement of remaining sensors. Moreover, the developed system takes into account the controller transition smoothness in terms of speed and torque transients. For automotive application purposes two control techniques are chosen to illustrate the consistency of the proposed approach: sliding mode for encoder-based control and fuzzy logics for sensorless control. The system control reorganization is managed by a fuzzy decision system. Simulations tests, in term of speed and torque responses, have been carried out on a 4 kW induction motor drive to evaluate the consistency and the performance of the proposed fault-tolerant control approach.