Open-Phase Natural Fault-Tolerant Scheme Based on Deadbeat Predictive Current Control for Symmetrical Six-Phase Vernier PM Motor

Abstract

Multiphase vernier permanent magnet motor (VPMM) has attracted more and more attention due to high torque density and fault-tolerant capability. However, the traditional natural fault-tolerant control based on field-oriented control (NFTC-FOC) uses PI controller as the current controller, which has complex parameter tuning and needs to improve the dynamic performance. The purpose of this paper is to propose a natural fault-tolerant control based on deadbeat predictive current control (NFTC-DPCC), the key of which is to replace traditional PI controller with deadbeat predictive current control, thus avoiding parameter tuning and improving dynamic performance. Similarly, the proposed NFTC-DPCC can automatically switch to fault-tolerant control by judging the reference voltage threshold in the x-y subspace without fault diagnosis. More importantly, the proposed NFTC-DPCC is always effective regardless of neutral point isolation or interconnection without reconfiguring the controller. By experimental comparison with NFTC-FOC for a symmetrical six-phase VPMM with neutral point isolation or interconnection, it is verified that the proposed NFTC-DPCC can achieve natural fault-tolerant control in multiple scenarios with improved dynamic performance.