Direct torque control of permanent magnet synchronous motor based on second order sliding mode

Direct torque control system of permanent magnet synchronous motor based on second order sliding mode speed controller is introduced to solve the problem that flux linkage and rectangular pulse are both too big in the direct torque control of permanent magnet synchronous motor, it is difficult to control at low speed. This method not only makes the state of system converge in limited time, decreases the torque at a low speed and lessens the flux linkage ripples, but also has strong robust to system parameters and external interference. Besides, the vibration in sliding mode control is eliminated effectively. The simulation results show the efficiency of the control stratagem proposed in the paper.