Fault tolerant control of multiphase multilevel motor drives - technical review

The multiphase multilevel motor drives are a promising solution for some high-power and high-reliability applications, since they have multiple power conversion routes, a large amount of redundant voltage vectors, higher equivalent switching frequencies and superior harmonic performance. It has great significance to exploit their remedial control strategies in depth to fully utilize their high fault tolerant capabilities. This paper will present an updated technical review of fault tolerant control schemes for multiphase multilevel motor drives. Based on exemplification of the diode neutral-pointclamping three-level (DNPC-3L) inverters and T-type NPC three-level (TNPC-3L) inverters fed asymmetric six-phase PMSM drives, the study is taken for both phase-leg faults and switch faults. Furthermore, the discussion on multiple-switch faults, short-circuit switch faults and switch and leg hybrid faulty conditions are discussed in this paper.