Research On Direct Torque Control Strategy Of Permanent Magnet Synchronous Motor Based On Sliding Mode Control

Our country adheres to the sustainable development strategy and promotes green and low-carbon development.Therefore,the development of new energy vehicles has been vigorously promoted.Compared with other motors,the permanent magnet synchronous motor has better running performance,lower cost,small size,light weight and light weight,and is used as the main drive motor of electric vehicles.Compared with other control strategies,direct torque control technology can better meet the needs of speed control of permanent magnet synchronous motors in new energy vehicles because of its excellent characteristics.However,there are obvious defects in the control process,so in order to improve its control performance,it needs to be improved.This is conducive to the long-term development of the electric vehicle industry and further promotes green travel.In this paper,the direct torque control strategy of surface-mounted permanent magnet synchronous motor is studied,and the modeling and simulation are carried out in MATLAB/simulink.The simulation results show that there is a large amount of speed overshoot and torque ripple;and when disturbance occurs,the stability is restored.long-term problems.In order to solve the existing problems,consider introducing the sliding mode variable structure control theory,aiming at the chattering phenomenon existing in the sliding mode control itself.The switching function in the sliding mode control law is studied and analyzed,and a new switching function F(s)is proposed.Through comparison and verification,the results show that the proposed switching function F(s)can effectively weaken the chattering phenomenon of sliding mode control.The torque and flux linkage sliding mode controller is designed based on the switching function F(s);and the global fast terminal sliding mode surface is used in the speed loop,and a sliding mode control law combining equivalent control and switching robust control is designed to replace the PI controller,forming a new and improved system.The simulation results show that the improved system effectively solves the above problems and improves the control performance of the system.