Improved predictive current control for permanent magnet linear synchronous motor
Aiming at the problem that predictive current control(PCC)of permanent magnet linear syn-chronous motor(PMLSM)is susceptible to parameter change,delay and load disturbance,an improved PCC based on second-order super twisting sliding mode observer(STSMO)was proposed.Firstly,a dy-namic mathematical model of PMLSM with uncertainty was established.Then,in order to compensate for the influence of parameter change and delay,STSMO was used to estimate the current in the next cycle and the disturbance voltage caused by parameter changes.The estimated value was used to calculate the reference voltage in the next cycle to improve the current tracking accuracy,the stability of the observer was proved by Lyapunov function.At the same time,the adaptive sliding mode controller(ASMC)based on the improved exponential reaching law was used to track the speed.By adding the state variables and sliding mode surface to the exponential reaching law,the current chattering is not only weakened,but al-so the robustness of the system is further improved.The results of hardware in the loop simulation experi-ment show that,compared with traditional PCC,the proposed method can effectively suppress the influ-ence of uncertainty on the system,and make the system have better tracking performance and robustness.
permanent magnet linear synchronous motorpredictive current controlsuper-twisting sliding mode observeradaptive sliding mode controlrobustness