A Novel Model Predictive Current Control for Fault Tolerant Permanent Magnet Vernier Rim-Driven Motor Based on Improved Sector Selection

Abstract

Fault tolerant permanent magnet vernier rim-driven motor (FTPMV-RDM) have a broad application prospect in ship electric propulsion systems due to its high torque density and strong fault-tolerant capability. In order to solve the problem of large number of alternating voltage vectors and complicated calculation process, in the paper, a novel model predictive current control algorithm based on improved sector selection (ISS-MPCC) for FTPMV-RDM is proposed to suppress torque ripple and reduce current harmonic content. Firstly, a set of fundamental voltage vectors is used for initial screening. Then, a secondary screening is performed using a value function to determine the pre-selected voltage vector, thus reducing the number of voltage vector enumerations in the system and effectively suppressing the generation of harmonic currents. Finally, optimization is carried out within this sector to obtain an optimal combination of switching states for one control cycle. To obtain good performance under single-phase open-circuit fault condition, a fault-tolerant control strategy based on the healthy decoupling transformation matrix is proposed. This strategy simplifies the fault-tolerant control by only requiring changes in the reference currents in the harmonic subspace. Hardware experimental results have validated the effectiveness of the proposed control strategy in this paper.