A Robust Predictive Current Control Method For PMSM Drive Based On Incremental Model

Predictive current control is one of the hot research spots in recent years,especially the predictive current control with PWM modulation(PPC).PPC is a model based strategy,and its performance largely depends on the accuracy of model,particularly the rotor’s flux linkage and stator inductance.If inductance in PPC mismatches with the real value,current oscillation,even current-loop instability will occur.While the mismatch of flux linkage between PPC and real value will lead to current static error and diminish the load-carrying ability.Therefore,the first priority is to improve the robustness against flux linkage and inductance mismatch while maintain the advantage of predictive controller.The robust predictive current controller is generally too complex,requiring many observers.Besides,the tuning process is difficult when implementing such strategies into different platforms due to the variation of motor parameters.This paper proposes a flux immunity robust predictive current controller called R-PPC.Firstly,incremental model is derived based on voltage equation,and it is used to design R-PPC controller.The selection of weighting matrix and current references is analyzed.In addition,the stability and static error analysis are also conducted to verify the effectiveness of proposed R-PPC method.Secondly,extended state observer(ESO)is introduced to improve the inductance robustness.Based on the model with inductance error,continuous and discrete ESOs are designed.The stability of ESO is analyzed and the selection criterion of observer gains is presented.Simulation results prove that ESO can accurately estimate voltage error caused by inductance mismatch.The inductance robustness of R-PPC can be enhanced by compensating the voltage error.Next,to further improve current performance,this paper adopts an adaptive dead time compensation method.Simulation and experimental results show that such compensation method can achieve desired performance when implemented in R-PPC.The harmonic distortions are greatly diminished.Finally,PPC and R-PPC are compared by simulations and experiments.The results reflect that R-PPC can operate without flux linkage while have good inductance robustness.The results also highlight the superiority of R-PPC over PPC.Besides,the effectiveness of R-PPC is also verified on GSK platform.