Research On Improved Sliding Mode Active Disturbance Rejection Control Of Permanent Magnet Synchronous Motor

Permanent magnetic synchrotron motor（PMSM）has been widely used in servo control fields such as aerospace,orbital traffic and intelligent robots due to its simple structure,high power density,small size and low moment of inertia.However,the PMSM is susceptible to external load perturbations,parameters variation,and other uncertainties during real operation.Therefore,PMSM is a nonlinear,strongly coupled time-varying system.In order to weaken the adverse effects of uncertainties and improve the robustness of the system,an improved sliding mode active disturbance rejection control method based on variable gain extended state observer（VGESO）and sliding mode control（SMC）based on improved reaching law was proposed.Firstly,the basic structure and working principle of PMSM were described,the PMSM vector control system was established based on the vector control theory,the influence of different uncertain factors on the system performance was analyzed,and the PMSM motion equation with uncertain factors was established.Secondly,aiming at the problem that PMSM’s system performance deteriorates when it is affected by external disturbances,parameter changes and other uncertain factors,an improved active disturbance rejection control method based on VGESO was proposed.The traditional active disturbance rejection control was to use the observer to observe and compensate the uncertain factors of the system,and then adjust the system performance through the nonlinear state error feedback loop,which has strong robustness to the uncertain factors.However,due to the problem of initial peak value,the traditional extended state observer will reduce the observation accuracy.Therefore,the variable gain coefficient was introduced into the gain term of the observer to form VGESO,which can reduced the initial peak value easily appearing in the traditional extended state observer.The simulation results show that the improved active disturbance rejection control method improved the observation accuracy of the observer and the speed tracking accuracy of the system.Finally,in order to further improve the robustness of the system,SMC based on improved reaching law was adopted to replace the nonlinear state error feedback loop in improved active disturbance rejection control.At the same time,because there are more parameters to be regulated,the improved gray wolf optimization algorithm（IGWO）was adopted to adjust the control parameters and fully play the performance of the controller.The simulation results showed that compared with the improved active disturbance rejection control based on VGESO,the improved sliding mode active disturbance rejection control method further enhances the robustness of the system.