Improved direct torque control of permanent magnet synchronous motor

Traditional direct torque control causes torque ripple naturally because of its basic Bang-bang control principle. The sliding mode variable structure control with fuzzy logic is presented in the paper. Mathematics model of permanent magnet synchronous motor in primary frame had been described. Sliding mode variable structure is used to design a reasonable sliding surface for minimum control errors. And fuzzy logic is applied to solve sliding mode wobbling problem. The method of fuzzy sliding mode variable structure control can reduce torque ripple greatly. Analysis results have been curved, which shown the control system still remains fast response and control robustness. The system control performances with the method have been improved obviously.