Disturbance Compensation-Based Model Predictive Flux Control of SPMSM With Optimal Duty Cycle

Abstract

Finite control set model predictive torque control (FCS-MPTC) is receiving more attention for electric drives, due to its intuitive idea, flexibility to incorporate constrains, and fast torque dynamic response. However, traditional FCS-MPTC requires heavy computation effort and has high torque ripple at steady state. The weighting factors of the cost function are hard to optimize to obtain desired performances. Moreover, torque tracking error exists because FCS-MPTC belongs to the open-loop control strategy. This paper proposes disturbance compensation-based model predictive flux control (DCB-MPFC) with optimal duty cycle (ODC) of surface permanent magnet synchronous motor (SPMSM). This paper first proves the uniformity of MPTC, MPFC, and model predictive voltage control (MPVC). The cost function based on the stator flux linkage vector can be converted to the equivalent cost function based on voltage vector. The role of the equivalent cost function is to compare the deadbeat vector with three pairs of vectors, which can reduce computation effort and torque ripple. In addition, the disturbance compensation strategy is proposed to eliminate torque tracking error. The proposed DCB-MPFC is verified effectively by experiments that are compared with traditional algorithm, proportional-integral speed loop-based mode predictive torque control (PI-MPTC).