Current Ripple Suppression for PMSM Predictive Control System Under DC-Link Voltage Fluctuation

In permanent magnet synchronous motor (PMSM) drive systems, DC-link voltage fluctuations can severely affect the steady-state performance of the system. Although traditional model-free predictive current control (MF-PCC) can enhance system robustness and reduce the impact of current harmonics, its current harmonics caused by DC-link voltage fluctuations can not be suppressed effectively. To solve this problem, this paper proposes a current ripple suppression predictive current control strategy based on a dual second-order generalized integrator (DSOGI). This strategy utilizes the DSOGI to extract fluctuation signals from the current signals that have the same frequency as the DC-link voltage fluctuations, achieving dynamic reverse compensation of the current ripple. Additionally, to address the signal delay issue associated with the DSOGI algorithm, the Lagrange interpolation method is employed to predict the signal and, in doing so, the compensation accuracy is improved. The experimental results verify the effectiveness of the proposed method. Compared to traditional methods, the proposed approach effectively reduces current ripple caused by DC-link voltage fluctuations and enhances the control system robustness.