Experimental assessments of a triple redundant 9-phase fault tolerant PMA SynRM drive

Fault tolerant machine drives are key enabling technologies in safety critical applications. The machine drives are expected to exhibit high performance in healthy conditions and accommodate as many faults as possible, namely open circuit or short circuit in the machine and inverter or even an inter-turn short circuit. This paper aims to assess a triple redundant 9-phase (3x3-phase) permanent magnet assisted synchronous reluctance machine (PMA SynRM) drive by comprehensive experimental tests under both healthy and fault conditions on a 35kW machine drive prototype. The healthy performance, fault behavior, fault detection and fault mitigation strategy are presented and assessed by extensive tests which demonstrate that the machine drive exhibits high performance and excellent fault tolerance with simple and cost-effective implementation. Therefore, the proposed machine drive has proven to be a practical candidate for safety critical applications.