Study On The Anti-load Disturbance Control Of Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor(PMSM)is widely used in high-performance servo drive system owning to its superior performance.At present,vector control due to structural and simple principle,high control accuracy,speed range,etc.is become mainstream control scheme of PMSM.However,for PMSM is a non-linear,multivariable system with strong coupling,it is difficult to establish a precise mathematical model of PMSM.In addition,there are many uncertainties such as complex operating conditions,parameter time-varying(for example inertia)and load disturbance.The traditional vector control system generally controlled with PI regulator is sensitive to variable parameters and load change,so it is hard to meet the requirements of high performance servo system which have strong robustness for load disturbances and parameter variations.The main works in this paper aimming at solving this problem are as follows.Firstly,the mathematical model of the PMSM was detailed introduced.Then,current main algorithm of load disturbance and inertia identification were analynized.Secondly,in order to improve the robustness of PMSM based on PI regulator for load disturbances and parameter variations,some methods are proposed:For load disturbance,an extended Kalman filter is adopted to estimate the speed,position and torque load of PMSM on-line.Then a variable feed-forward gain compensation control strategy has been proposed to suppress impact of load disturbance on operating performance of PMSM.For time-variable inertia,model reference adaptive algorithm is proposed to identify inertia on-line.And the parameters of extended Kalman filter are on-line real-time updated according to the estimated inertia,which guarantees accuracy of the observed value of extended Kalman filter.Simulation results show that proposed method is reasonable and effective.Finally,a large quantity of experiments has been done on the variable load and variable inertia experimental platforms.Experimental results demonstrate that:(1)proposed variable feed-forward gain compensation control strategy based on extended Kalman filter can effectively suppress the impact from load disturbance on operating performance of PMSM;(2)the inertia of PMSM can be preferably identified by model reference adaptive algorithm.