Improved Sliding Mode Speed Control of Permanent Magnet Synchronous Motor Considering Demagnetization Fault
In order to solve the problem of demagnetization of the control system due to amplitude loss of perma-nent magnet synchronous motor(PMSM),an improved sliding mode speed control method combined with online ob-servation of magnetic fluxes is designed.Firstly,a mathematical model of PMSM considering the magnitude loss and flux rate of change is established.Secondly,a velocity outer ring sliding mode controller based on the constant velocity approximation law is designed.At the same time,in order to improve the immunity of the sliding mode speed control-ler to magnetic loss fault,the sliding mode observer is used to observe the flux change in real-time,and the parame-ters in the controller are updated synchronously.Finally,by comparing with PI control and sliding mode speed control,it is verified that the designed method can not only track the change of magnetic linkage in real-time,but also effectively improve the dynamic and static performance of the control system under magnetic loss fault.