Speed Control Of Pmsm Based On Sine Cosine Chaotic Grasshopper Optimization Algorithm

Permanent magnet synchronous motor(PMSM)is a multivariable,strongly coupled time-varying nonlinear complex system.Traditional PI control has been difficult to meet the high precision requirements for speed control of PMSM servo system.In this paper,the control accuracy of the motor speed is improved by designing the speed loop in the PMSM vector control system.Composite control strategies are often used in the design of servo control systems for PMSM.Firstly,a sine cosine chaotic grasshopper optimization algorithm(SCCGOA)based on the standard grasshopper optimization algorithm(GOA)is proposed in this paper.In each iterative,the optimal solution is first optimized by GOA global search and then updated by chaotic local search where the sine cosine search mechanism is introduced into the carrier map of the chaotic variable.Secondly,in order to ensure that the new algorithm SCCGOA has effect on the speed loop designed by PI controller,optimize the parameters of the classic PID controller as a prerequisite experiment where the second-order systems widely existed in the field of control engineering are selected as the controlled object.The step response of these PID control systems is compared with the optimization results of the original algorithm GOA and sine cosine algorithm(SCA).Thirdly,a self-adaptive PI regulator is designed based on this new algorithm as the speed loop of the PMSM vector control system.The speed response is observed under sudden load change and compared with those optimized by the original algorithm GOA,the classical group optimization algorithm particle swarm optimization(PSO)and another new optimization algorithm,the whale optimization algorithm(WOA).Finally,a fuzzy PI controller is designed based on the traditional PI regulator combined with fuzzy control strategy,then quantization factors,scale factors and membership functions of this fuzzy controller are simultaneously optimized using SCCGOA.The system’s speed response under sudden load change is compared with the result of self-adaptive PI control when the self-adaptive fuzzy PI controller is used as the speed loop in the PMSM servo system.In addition,the different speed tracking effects are compared under these two self-adaptive controllers given different speed signals.When SCCGOA is used to verify its optimization performance for PID parameters,the experimental results show that SCCGOA has faster convergence rate and higher convergence accuracy than the original algorithm GOA and SCA,and its step response shows better comprehensive dynamic performance.The load sudden change experiment on optimizing PI parameters in speed loop using SCCGOA shows that the dynamic performance of the speed response is better than GOA,PSO and WOA.In this experiment,if the fuzzy PI controller replaces the PI controller,the system is more robust.In the speed tracking experiment,the self-adaptive PI controller and fuzzy PI controller based on SCCGOA are used as the speed loop respectively.The speed tracking curve shows that the tracking under self-adaptive fuzzy PI control is more timely,accurate and robust.