Sliding Mode Control Based on Six-Phase PMSM Speed Control System

Due to the consideration of the atmospheric pollution, electric vehicles (EV) have become more and more popular. The permanent magnet synchronous motors (PMSM) have been widely used in EV because of its high efficiency, high torque density and ability of fault-tolerant operation. In this paper, firstly, a six-phase PMSM mathematical model was built using space vector decoupling theory. Based on this, the vector control is used to design the double closed-loop current and rotate speed control system. The precision of the model has been verified with MATLAB own three-phase PMSM model by current and torque curve. In order to realizing the good performance of torque and rotate speed tracking, traditional PI controller cannot eliminate static error and meet the high frequency requirements in EV system. A variable-structure sliding mode control (SMC) is designed for six-phase PMSM speed control system to solve the uncertainty problem in high degree coupling environment. By simulation research, the results demonstrate that slide model control has the advantage of rapid response, no overshoot and stability compared with PI controller.