Universal Fault-tolerant SVPWM Strategy with Simplified Fault Diagnosis for Five-phase PMSM under Arbitrary Phase Single Open-Switch fault

The standard inverter topology of five-phase permanent magnet synchronous motor (PMSM) has weaker fault-tolerant capability than other complex drives. Additionally, traditional open-switch fault-tolerant strategies demand precise diagnosis methods involving numerous states of different phases and reconfiguration according to fault phase change. To enhance fault-tolerant algorithm applicability, a universal fault-tolerant space vector pulse width modulation (SVPWM) strategy without extra hardware is proposed to handle single open-switch fault for five-phase PMSM. The most significant innovation is to achieving fault-tolerant operation for arbitrary phase open-switch fault without requiring adjustments based on fault phase location. Owing to this, corresponding diagnosis process can be simplified. In diagnosis process, the positive and negative relationship of the third harmonic currents within faulty half cycle is adopted to obtain the overall diagnosis result without requiring precise identification. In fault-tolerant algorithm, post-fault basic voltage vectors are firstly reconstructed based on switching state analysis. Then, to minimize the influence of harmonic subspace and improve SVPWM control precision, virtual voltage vectors are synthesized based on geometric meaning of basic voltage vectors. Further, through establishing vector sets involving five phases and summarizing their intersection regions, universal virtual voltage vectors are determined. Finally, the effectiveness of proposed method is verified by experiments.