Optimization and Reduction of DC Winding Induced Voltage in 5Slot/7Pole Five Phase Non-overlapped Stator Wound Field Flux Switching Machine

The five phase non overlapped stator wound field flux switching (WFFS) machine with most simple machine structure i.e. 5-slots and 7-poles is analyzed and optimized in this paper and the design analysis briefly discuss the DC winding induced voltage phenomena. The DC winding induced voltage can produce the current ripple in the DC windings and hence it creates issues to the DC power source and enhances the challenges to machine controllability, mainly for high speed operation. The initial machine optimization is performed to decrease the DC winding induced voltage while the maximum value of the average output torque is maintained and machine size is considered constant. For optimization approach, krigging technique arranged with Latin hyper Cube Sampling (LHS) and genetic algorithm (GA) is implemented because of relevance to non-linear data. The optimized design has achieved the 21.42% reduction in DC winding induced voltage at no load condition and 27.65% reduction under on load condition. Furthermore, two reduction methods i.e. chamfering and optimization of the rotor pole arc, are analyzed to reduce the DC induced voltage and 33.50% and 42.45% reduction as compare to initial design is achieved for chamfering at no load and on load conditions respectively while 36.06% and 49.20% reduction for rotor pole optimization is achieved at both operating conditions, respectively.