Magnetic Loading of Fractional-Slot Three-Phase PM Motors With Nonoverlapped Coils

This paper deals with the magnetic analysis and design of fractional-slot permanent-magnet (PM) motors with nonoverlapped coils. The main focus is on the computation of the stator current reaction and of the self and mutual inductances. The goal of this paper is to give an analytical prediction of these quantities. Simple but effective rules are found for a rapid choice of the geometry of fractional-slot PM machines. Finite-element simulations and experimental results confirm the analytical predictions. This paper also aims at suggesting general considerations for the appropriate choice of the combinations of number of poles and slots and the winding type.