Current Optimization for a Multi-Phase Machine under an Open Circuit Phase Fault Condition

In this paper, a practical method based on a symmetrical component transformation is proposed to analyze and optimize the current for a multi-phase machine under open-circuit phase conditions. Two kinds of current optimization are considered: stator copper loss minimization and inverter peak current minimization. Application of the method is described for a five-phase machine. The fault conditions investigated are single, double, and triple open-circuit phase faults. Optimized solutions for four-, six-, and seven-phase machines, with one open-circuit phase, are also presented.