Observer-based sensorless control of permanent magnet synchronous motor for electrical vehicle

In order to further improve the performance of sliding mode variable structure control for sensorless control of permanent magnet synchronous motor (PMSM). Analyze the problems of singularity, chattering, and slow convergence of the terminal sliding mode control. A new reaching law based on the nonsingular terminal sliding mode control is proposed, the advantages of the reaching law and nonsingular terminal sliding mode was combined. It not only can solve the problem of the singularity of the terminal sliding mode, but also improve the reaching performance when system state is far away from sliding mode surface. The novel method can shorten the convergence time, and weaken the system chattering. Simulation results show that the design method can effectively improve the dynamic performance and robustness of the system.