Speed And Position Control Of Surface Permanent Magnet Synchronous Motor Based On Sliding Mode Wariable Structure Methods

Surface permanent magnet synchronous motor can be regarded as a special case of salient pole permanent magnet synchronous motor.The torque of this kind of motor is only linearly related to q-axis current,but independent of d-axis current.Its control model is simple and has been widely used in robot,aerospace,precision CNC machine tools and servo systems.Surface permanent magnet synchronous motor is a complex object with multi input,strong coupling,nonlinear and variable parameters.The conventional control is easy to be affected by external interference and internal parameter changes,and its robustness is not strong enough to meet the requirements of high performance.Sliding mode variable structure control(SMVSC)is widely used in speed control of surface permanent magnet synchronous motor(SPMSM)because of its low requirement for system mathematical model accuracy,insensitive to system parameter perturbation and external disturbance,and simple controller design.In this paper,the control system of surface permanent magnet synchronous motor is studied based on sliding mode variable structure method.The main research contents are as follows:(1)The sliding mode control method of surface permanent magnet synchronous motor(SPMSM)and the significance of its control system are described in order to support the related research work of this project.(2)The basic idea and development status of sliding mode variable structure control are summarized,and the design method of sliding mode variable structure control used in this paper is introduced in depth.(3)Aiming at the influence of time-varying parameters,external load disturbance and severe chattering of traditional first-order sliding mode system on system performance of surface permanent magnet synchronous motor speed control system,integral sliding mode variable structure control and fuzzy control algorithm are applied to the system.In order to solve the windup phenomenon caused by integral link and current limiting link in the model controller,anti saturation is added to the controller And link can effectively weaken chattering and eliminate windup phenomenon,and improve the dynamic stability of the system.(4)In order to improve the performance of surface permanent magnet synchronous motor position tracking control system,especially when the system has parameter perturbation or load disturbance,it is difficult to achieve high performance position tracking control by conventional control At the same time,better tracking response performance of the system is obtained.(5)In the control system under complex environment,the external disturbance and system parameter perturbation are the factors that can not be ignored to improve the accuracy of motor control system.To solve this problem,a composite control strategy of sliding mode variable structure control combined with sliding mode disturbance observer is proposed.This compound control strategy can effectively reduce the motor speed and electromagnetic torque ripple caused by internal and external disturbances,and improve the control accuracy of the system.(6)Mechanical sensors not only increase the volume and cost of the motor control system,but also increase the complexity of the system structure,and even seriously affect the reliability and safety of the system.A new type of second-order sliding mode observation is proposed to replace the mechanical sensor to estimate the speed and position of the rotor.The proposed new sliding mode observer can eliminate chattering without low-pass filter and phase lag,so the system is more robust.