Optimized Field-Weakening Operation of PMSM Modulated Model Predictive Control Using Predictive Current Error Margin
Qinghua Dong, Bo Wang, Liqun Xia, Yong Yu, Minghe Tian, Dianguo Xu
Abstract
Considering the intrinsic defects of finite control set MPC (FCS-MPC), e.g., torque ripple and various harmonic frequencies, the modulated model predictive control (M2PC) has been regarded as a promising approach to achieve high performance of permanent magnet synchronous motor (PMSM) drives. However, the M2PC still faces non-minimum tracking error and unreasonable trajectory settings when rated-speed operation extends to the field-weakening (FW) region since the intervention of multiple constraints of voltage and current has to be taken into account. To address this problem, an M2PC-based scheme is proposed to realize the field-weakening operation with minimum tracking error and reasonable trajectory setting. Specifically, the equal proportion algorithm is replaced by an algebraical way for minimum tracking error in the over-modulation region; the predictive current error margin is used to preset the current trajectory in FW operation. Besides, the pre-triggering method is applied to reduce the control delay and eliminate the cumulative error, which improves the tolerance of parameter perturbation. Comparison results conducted on a Zynq7020-based PMSM setup validate the superiority of the proposed method regarding the capability of high-speed operation and high-dynamic performance.