Research On Control Strategy Of Permanent Magnet Synchronous Motor Based On Double Closed Loop Improvemen

With its small size,high power density and high power factor,the permanent magnet synchronous motor has gained wide attention and application in many fields such as railway traction,aerospace,aviation,machine tools and military.However,with the development of science and technology and social progress,the traditional control method gradually becomes difficult to achieve high precision control requirements,so an efficient control method is needed.The thesis takes the permanent magnet synchronous motor as the research object,and makes improvements to the speed and current loops in the double closed-loop control system of the permanent magnet synchronous motor through modern control theory algorithms.The main research work is as follows:Firstly,in the double closed-loop control system of a permanent magnet synchronous motor,the speed loop adopts a sliding-mode variable structure control method.A new convergence law is developed for the jitter problem,which improves on the exponential convergence law by designing the convergence speed according to different convergence states and influencing the convergence time by adjusting the speed,so as to effectively suppress the jitter of the state variables.The convergence law is theoretically proven,a simulation model is built and the results are compared and analysed with the exponential convergence law in MATLAB/simulink.Secondly,a compensated differential-free predictive control method is adopted for the current controller in the double closed-loop control system.The problem of current static difference due to parameter sensitivity of the differential-free predictive control algorithm is first analysed,and an observer based on internal mode control is designed for this phenomenon,in which the observed disturbance caused by the mismatch of model parameters is introduced into the voltage equation of the motor as compensation,and the stability of the observer is analysed by The stability of this observer is analysed theoretically and its simulation is verified on MATLAB/simulink.It is proved through simulation experiments that the introduction of the observer can improve the problem of more sensitive parameters and also optimise the anti-load disturbance capability of the system,verifying the correctness and effectiveness of the control algorithm proposed in this chapter.Finally,the improved dual closed-loop control strategy for permanent magnet synchronous motors studied in this paper is verified experimentally,using the TMS320F28335 as the core motor control experimental platform for verification,and the improved dual closed-loop control algorithm is compiled and debugged on the CCS software platform to verify the feasibility and superiority of the proposed method.