Fault Control Strategy for Torque Ripple Reduction in Single-Phase Open Fault of OW-PMSM Fed by a Dual Inverter with a Common DC Bus

Detecting and fault-tolerant control (FTC) strategy is very important to improve the reliability of the drive system. Various control strategies for zero-sequence current (ZSC) reduction have been studied for open-winding permanent magnet synchronous motor (OW-PMSM) fed by a dual inverter with a common DC bus system. However, during single-phase open faults, the use of conventional control methods for OW-PMSM results in significant torque ripple due to degradation in ZSC suppression performance. Therefore, this article proposes a method to reduce torque ripple through a novel $q$-axis compensation method. The proposed method can be implemented with a relatively simple modulation method during fault modes. A resonant controller is introduced to reduce second and fourth order harmonic currents. Additionally, the paper presents a fault detection method through ZSC estimation. The effectiveness of the proposed method is verified through simulation and experimental results.