Remedial Strategies of T-NPC Three-Level Asymmetric Six-Phase PMSM Drives Based on SVM-DTC

• Published in: IEEE transactions on industrial electronics (1982) Vol. 64; no. 9; pp. 6841 - 6853
• Main Authors: Wang, Xueqing, Wang, Zheng, Cheng, Ming, Hu, Yihua
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.09.2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Asymmetric six-phase permanent-magnet synchronous motor (PMSM) drives; Asymmetry; Coils (windings); Dynamic response; Fault tolerance; Fault tolerant control; Fault tolerant systems; Faults; Fluxes; Harmonic analysis; Inverters; Permanent magnets; Perturbation; Space vector modulation; space vector modulation direct torque control (SVM-DTC); Stators; Support vector machines; Switches; Synchronous motors; T-type neutral-point-clamping (T-NPC) inverter; Voltage control
• ISSN: 0278-0046; 1557-9948
• DOI: 10.1109/TIE.2017.2682796

In this paper, novel remedial direct torque control (DTC) schemes are proposed for open-circuit faults in T-type neutral-point-clamping (T-NPC) three-level asymmetric six-phase permanent-magnet synchronous motor (PMSM) drives. First, a simplified space vector modulation (SVM) is designed and applied for DTC-controlled asymmetric six-phase drive, in such a way that both good current harmonic performance and fast dynamic response are available. Based on the SVM-DTC scheme, a remedial strategy is proposed for the open-circuit faults in phase windings. The key is to derive the relationship between the stator fluxes and the stator voltages of all phases under faulty condition. Then, a derived perturbation term is compensated for normal voltage references, and the fault-tolerant scheme is, thus, implemented without changing control structure of normal condition. The remedial DTC schemes are also studied and proposed for open-switch faults in T-NPC six-phase drives. The modulation methods are redesigned for the faults in half-bridge switches and NPC switches. The experiments are carried out on a laboratory prototype to verify the validity and performance of the proposed fault-tolerant control schemes.