Robust Control Research For Vehicle Permanent Magnet Synchronous Motor Based On Generalized Predictive Control

This paper focuses on vehicle permanent magnet synchronous motor(PMSM).To improve system robustness,a generalized predictive control strategy with the disturbance observer for vehicle PMSM is proposed.The proposed control strategy is verified via simulation research.The main research works can be summarized as follows.(1)The development status of PMSM drive system and robust control technology is introduced.A mathematical model of PMSM considering system disturbance is established,providing the basis for the derivation of the predictive control algorithm.Meanwhile,the principle and realization process of the field-oriented control(FOC)strategy and the stator current control strategy are described.The simulation model of PMSM is established.A simulation analysis was carried out based on the model and the results showed that it is difficult for the proportional-integral(PI)controller to achieve ideal control performance under system disturbance.(2)Concerning the robustness of vehicle PMSM,a generalized predictive current control strategy based on nonlinear disturbance observers(NDO)is proposed.The nonlinear generalized predictive control(NGPC)strategy is introduced.Based on the continuous mathematical model of the PMSM,Taylor series expansion is used to predict the system response over a finite horizon,and the objective function is optimized to design the current controller.To improve the robustness of the control system,a NDO is introduced to estimate the system disturbance and feedforward compensated to the controller.The simulation results verify the proposed control strategy has stronger current control performance than PI controller under system disturbance.(3)Regarding the robust speed control of vehicle PMSM,a NGPC strategy based on the extended state observer(ESO)is proposed.The speed predictive controller is designed based on the NGPC strategy.Concerning the problem of external disturbance affects the PMSM speed control performance,an ESO is designed to estimate and compensate the system disturbance.Simulation results show that the proposed control system has fast speed response and strong anti-disturbance performance.(4)Concerning the robust speed-current control of vehicle PMSM,a NGPC and sliding mode disturbance observer(SMDO)in a cascaded structure is proposed.The robust cascaded predictive controller is designed based on the cascade structure of FOC and NGPC strategy.However,the control strategy has steady-state errors with external disturbance,it cannot deal with the influence of system disturbances.Therefore,a SMDO with a novel reaching law is introduced to estimate the system disturbance and feedforward compensation to the controller.The designed SMDO is reliable and its parameters are easily regulated.Besides,the proposed controller facilitates the handling of system constraints.Simulation results verify the proposed control strategy has good static and dynamic performance and strong robustness.(5)Referring to the problem of complicated cascade control structure and large amount of calculation,a single-loop control strategy based on NGPC is proposed.The single-loop controller based on the NGPC strategy of PMSM is designed.Meanwhile,the current limiting of the single-loop structure is designed based on the deadbeat control principle.Concerning unmatched disturbance,such as PMSM parameters changes and external disturbance,a NGPC strategy based on optimized objective functions and a NGPC strategy based on a SMDO are designed to suppress the influence of system disturbances.The structure of both controllers is simpler and stable.It is easy to implement in engineering.The simulation results show the both controllers can effectively eliminate the influence of system disturbance,and achieve fast dynamic response and strong robustness.With the proposed control strategy,a PMSM system with excellent dynamic performance and strong robustness can be obtained.This paper provides guidance for the design of NGPC robust controller for PMSM,and provides a solution for the robust control of vehicle PMSM.