The impact of the third order current harmonic cannot be ignored in a five-phase permanent magnet synchronous motor (PMSM), on the contrary of the three-phase PMSM. So, to realize the speed sensorless control for PMSM, a Sliding Mode Observer (SMO) is suggested with consideration the impact of third order harmonic. At the outset, a Sliding Mode Control (SMC) with injection of the third order current harmonic is designed for speed sensorless control of PMSM model for Electric Vehicle (EV). Then, Sliding Mode Observer is built to estimate the motor speed, torque and current in (d,q) frame, in order to improve the performance of sensorless control strategy. Besides, the stability of the SMC and SMO are studied using Lyapunov stability criteria. The feasibility of this technique will be evaluated using MATLAB/Simulink platform.

The present paper deals with an active fault-tolerant speed tracking of a five-phase permanent magnet synchronous motor with currents and speed sensor failures. The active fault tolerant control scheme, integrating a sliding mode observer and backstepping controllers, is proposed to provide a continuous drive operation of the five-phase permanent magnet synchronous motor, even during more than one sensor fault occurrence. The sliding mode observer is designed to generate the residual signal necessary for the detection stage, whereas speed and current backstepping controllers handle the operation of the five-phase permanent magnet synchronous motor thanks to their ability to consider the nonlinearities of the system model in generating a control law that is robust enough in healthy and faulty cases. Furthermore, the FTC strategy uses the information received from the fault-tolerant switching block in terms of the measured and the observed currents and speed signals. To gain the maximum benefit of the sliding mode observer’s robustness to random noises and its ease of implementation, the observed currents and speed of the five-phase permanent magnet synchronous motor have been estimated. The simulation results are conducted to show the effectiveness of the proposed FTC control scheme and to prove its high performance in fault detection and tolerant control for the five-phase permanent magnet synchronous motor, since it significantly outperforms the performance provided by traditional methods.