Improved Duty Cycle Model Predictive Current Closed-Loop Control With Composite Sliding-Mode Disturbance Observer for IPMSM

Aiming at the problems of current fluctuation and dependence of control performance on model parameters accuracy in finite control set model predictive current control (FCS-MPCC) of interior permanent magnet synchronous motor (IPMSM) drive systems, an improved duty cycle model predictive current closed-loop control (IDC-MPCC) strategy with composite sliding-mode disturbance observer (CSMDO) is proposed. To begin with, different single-phase voltage vectors are selected to synthesize the reference voltage vector, and the zero vector is split equally for redistribution. The control performance of the system for the transient state is improved without traversing multiple sectors for optimization. In addition, to improve the performance of IPMSM with mismatched parameters, the CSMDO is designed. The variable gain term approach law is improved, and the chatter of the observer is eliminated. The exponential approximation term is improved through the addition of the power term, and the speed of convergence for the system state is increased. Furthermore, the control delays induced by computation and sampling are compensated by the discrete-time-based closed-loop feedback of the CSMDO. The dependence of control performance on the exact model parameters is reduced, and robustness is further enhanced. Finally, the correctness and effectiveness of the proposed strategies are proved by the experimental results.