Research On The Speed Control Method Of The Permanent Magnet Synchronous Motor Based On Model Design

The PMSM is widely applied to the industries dues to its excellent characteristics,such as,simple structure,small size,high power density,low noise and friendly maintenance.However,the practical permanent magnet synchronous motor(PMSM)system is multi-variable,strongly coupled and non-linear,which is easily affected by unmodeled dynamics,parameter variations and load disturbance.The PI controller is usually applied to the speed regulation of the PMSM,owing to its simplicity and low computational cost.However,the parameters of PI controller can not be adjusted automatically to meet the high-performance control requirements of permanent magnet synchronous motor system,which has poor robustness and poor control effect.When the PMSM is controlled by PI controller,the parameters of PI controller can only be adjusted artificially for many times to reach the optimal value,and there is no automatic regulation mechanism.For this problem,the particle swarm optimization(PSO)is used to optimize PI controller.Each particle's position represents a set of PI controller parameters,an objective function is set.When the particle's position makes the objective function reach the optimal value,the PI controller's parameters are the optimal value,which can adjust the parameters of the PI controller automatically.However,the PSO has been used to control the speed of PMSM only in offline mode.Because of the change of inertia and disturbance in real dynamic system,only a set of parameters of PI controller can't meet the needs of the system.Therefore,the parameters of the controller must be fine-tuned in real time to keep the system in a high precision state at any time.Therefore,a PSO algorithm is proposed to optimize the parameters of PI controller for on-line system in real-time for speed regulation of PMSM.The PSO is used to optimize the proportional gain and integral gain of speed PI controller of variable inertia PMSM drive system in real time.Variable evaporation coefficient is introduced to replace the classical evaporation constant.A simulation model is built on the platform of MATLAB/Simulink.The simulation results verify the good control performance of the proposed algorithm.Then,because of the sliding mode control has simple structure,sensitivity to system parameter changes and has strong robustness,sliding mode control is applied to the speed regulation of permanent magnet synchronous motor,but the conventional sliding mode control(CRL)can't suppress the chattering phenomenon very well,so an enhanced exponential reaching law(EERL)is proposed,which is based on the selection of exponential terms.In this method,the system state(error signal)is related to the gain of the switching function.If the trajectory of the system state variable is far from the sliding surface,the gain of the switching function will increase.On the contrary,if the trajectory of the system state variable approaches the sliding surface,the gain of the switch tends to zero.Therefore,it can adapt to the change of system state and sliding surface.Compared with the CRL,the reaching law can reduce the arrival time and suppress the chattering phenomenon.In order to ensure the system performance while achieve the minimum resource utilization of embedded processors,an event-triggered control strategy is adopted,which makes the system robust and saves energy costs.