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

With the progress of permanent magnet material manufacturing process,the cost of permanent magnet synchronous motor(PMSM)is getting lower and lower,which has great application prospect in the direction of power drive.The PMSM speed control system with direct torque control(DTC)strategy has the advantage of fast dynamic response,but there are problems such as torque chattering and long time to restore steady state at low speed.Taking the SPMSM as an example,this paper deduces the mathematical models under different coordinate systems,builds the space vector pulse width modulation system,and establishes the speed control system model on the simulation platform.Aiming at the problem of torque chattering,sliding mode variable structure and fuzzy control are added to shorten the response time and weaken the torque chattering,and improve the robustness of the system.Firstly,the torque controller and flux linkage controller are designed by using the secondorder super-helical sliding mode algorithm,and the stability proof and quantitative analysis of the controller are carried out.Through the analysis of the experimental simulation data,it is proved that the new reaching law can effectively weaken the torque chattering and shorten the response time of the system.Secondly,in order to solve the problem of large speed overshoot of the control system,a fuzzy PID controller is built by using fuzzy control,and an adaptive algorithm with fewer iterations is designed to optimize the controller,and a fuzzy variable parameter adaptive PID controller with fast optimization characteristics is built.The experimental simulation shows that the improved DTC system can improve the speed overshoot,and the fuzzy adaptive PID controller can quickly feedback the change of error into the closed-loop system,which improves the control performance of the DTC system.Finally,the simulation parameters are adjusted several times in the discrete simulation environment,and the simulation experimental data are compared to verify that the improved DTC system has small dynamic and static errors and strong stability.