Research On Sensorless Control Of Permanent Magnet Synchronous Motor Based On IST-SMO

The research content of this article is sensorless control technology of permanent magnet synchronous motor which has been widely used in industrial production and household appliances in recent years.The problem of estimation error and poor anti-disturbance capability in sensorless control is studied.According to the principle of super-twisting algorithm and disturbance observer,a sensorless control method is proposed to resist load disturbance,which is designed based on the improved super-twisting sliding mode observer.Firstly,the mathematical models of permanent magnet synchronous motor in distinct coordinate systems are established.The vector method of _di(28)0 is selected as the basic strategy of sensorless control.After analyzing the basic principles of sliding mode variable structure control and second-order sliding mode control,the super-twisting sliding mode observer is constructed by using the super-twisting sliding mode algorithm and the current equation inα-βcoordinate system.On the basis of the observer,an improved super-twisting sliding mode observer is designed to diminish chattering,in which the gain varies with the estimated speed and the sigmoid function is used as the sliding mode switching function.The proposed observer is simulated and analyzed in simulink to verify its ability to improve the estimation accuracy.Secondly,for the problem of poor anti-jamming performance in the sensorless control method of velocity loop using PI controller,according to the basic principle of disturbance observer,an improved load disturbance observer is proposed after considering estimation error in the estimated speed.The observed disturbance value is feedforward compensated to the velocity loop controller to improve the disturbance rejection and dynamic response of the sensorless control system.The simulation results show that the proposed sensorless control method based on two improved observers is correct and feasible.Finally,the TMS320F28335 of TI is selected as the principal controller to devise the hardware circuit of speed control board for permanent magnet synchronous motor.According to the improved super-twisting sliding mode observer and improved load disturbance observer,the relevant software program is written,and the experimental platform is constructed to confirm the correctness of the suggested control approach.The experimental outcomes additionally prove that the designed sensorless control method based on improved super-twisting sliding mode observer which can resist load disturbance can not only increase estimation precision of rotate speed and rotor position,but also enhance the immunity of the control system.