Performance improvement in mini-type brushless DC motors with fractional-slot concentrated windings

This paper presents the numerical analysis and performance optimization of mini-type fractional-slot concentrated windings (FSCW) brushless DC Motors by using voltage source field-circuit coupled finite element method. Several slot/pole combinations, different stator/rotor structures were discussed here. The goal of the research was to improve the performance of this kind of mini-type BLDC motors which were using under limited volume and other special requirements. By choice of slot/pole combinations and sinusoidal rotor field treatment, the prototypes met the technical requirements.