Adaptive Fuzzy Sliding Mode Control Of Permanent Magnet Synchronous Motor

With increasing attention of energy conservation and environmental protection,permanent magnet synchronous motors(PMSM)are widely used with high efficiency and small size.With the improvement of the servo system’s requirements for control accuracy and anti-interference ability,the control algorithm for the nonlinear characteristics of the motor drive system has become the focus of research.In order to improve the overall performance of the motor drive system,researchers at home and abroad have proposed adaptive control,intelligent algorithm control,PID control,sliding mode control and other algorithms.Among them,sliding mode control is not susceptible to external disturbances due to its robustness.And the advantages of time-varying influence of internal parameters have become one of the most important algorithms for controlling PMSM systems.However,the performance of the system will be affected by the inherent chattering phenomenon of sliding mode control.Scholars try to reduce the chattering by redefining the sliding mode,constructing a state observer,and adjusting the sliding mode parameters.Aiming at the problem of poor control effect and increased chattering caused by the traditional exponential approaching law due to the fixed approaching parameters,this paper redesigned the exponential approaching law and combined it with the fuzzy algorithm to realize the automatic approaching parameters.Adaptation.Aiming at the problem of many rules in fuzzy algorithm and inaccurate manual selection,the improved differential evolution algorithm is used to optimize fuzzy rules,and the precise design of fuzzy rules is realized.In the specific research,the system performance is taken as the fitness function,and the fuzzy rules applicable to the current control system are obtained through the differential evolution optimization algorithm.Then,the optimized fuzzy rules are applied to the new fuzzy sliding mode controller,and compared with the two traditional controllers.The results show that the new controller is effective.The chattering and anti-jamming capabilities have been improved.The problem that the traditional observer will indirectly transmit sliding mode chattering,resulting in larger estimation errors is focused.Based on the idea of quasi-sliding mode,this paper designs a new observer to reduce the chattering phenomenon of the system.The thickness of the boundary layer can be adjusted adaptively after the improved sliding mode observer enters the sliding mode.Finally,it is compared with two traditional sliding mode observers.The simulation results show that the sliding mode observer designed based on the new fuzzy hyperbolic tangent function can effectively reduce noise and improve observation accuracy.