Research On Speed Loop Control Strategy Of Permanent Magnet Synchronous Motor

Because of its advantages of small size,high efficiency,light weight and low noise,permanent magnet synchronous motor(PMSM)has been widely used various fields,and people’s control demand for PMSM is also higher and higher.As an important part of motor motion control,the speed loop needs good dynamic response,wide range of speed regulation and strong anti-disturbance ability to satisfy the demand of high performance ac servo system.Therefore,research on speed loop control strategy of PMSM has great study value.Based on the design of speed loop controller in vector control system,this paper presents a single parameter adjustment method for the difficult parameter tuning problem of PI controller.,which is proposed according to the design idea of internal model control(IMC),and the control performance is improved by parameter identification and load torque compensation.At the same time,aiming at the windup phenomenon of speed control based on Uncertainty and Disturbance Estimator(UDE),the piecewise tracking back calculation and integral state prediction anti-windup algorithm are introduced,and the stability is proved.The research contents of this paper are as follows:Firstly,the physical structure of PMSM and its mathematical models in different coordinate systems are introduced,as well as the basic principle and system components of vector control.Secondly,in order to solve the complex problem of parameter tuning of traditional PI control,the internal mode controller is applied to the speed loop of PMSM,and the equivalent PI controller with only one parameter to set is derived,giving full play to the good external interference rejection ability of the internal mode controller.At the same time,the control performance obtained at this time is affected by the accuracy of model parameters and load torque,which is the compensation for the controller.Therefore,the least square method and model reference adaptive control(MRAC)are adopted to identify the motor’s moment of inertia,so as to obtain a relatively accurate reference model for IMC.The direct calculation method of pseudo-differential structure and Luenberger observer are used separately to estimate the load torque,which can be used as the compensation of the controller.both of the two algorithmscan make the load torque convergent rapidly to the real value,which improves the dynamic performance of the designed internal mode controller.Then,considering the influence of parameter changes on the system,UDE is applied to the speed control system of PMSM to obtain the two-parameterized speed loop controller,and the corresponding parameter setting idea is analyzed.Considering the windup phenomenon in the practical application,the piecewise tracking back calculation method and integral state prediction method are introduced,which can effectively improve the dynamic performance of the controller.Their control effect is analyzed theoretically and both of them are proved to be stable.Finally,in order to verify the correctness of the proposed single-parameterized and double-parameterized speed loop controllers,Matlab/Simulink is used for simulation and analysis of the above control system,and the speed closed-loop experiment is implemented on the experimental platform based on TMS320F28335 to verify the effectiveness.