Derivation of unaligned permeance model of the SRM air-gap between stator and rotor teeth using simplified 3-D AFP method

This paper discusses the derivation of the total unaligned permeance model of the air-gap between the stator and rotor teeth of a single tooth per pole 6/4 configuration switched reluctance motor (SRM) using simplified 3-D assumed flux path (AFP) method. All the effective mutual and leakage flux in the air-gap region in the X-Y-Z planes are all being considered in the permeance calculation. The flux linkage path patterns are based from those derived by the finite element (FE) simulation. This allows a simple, fast and accurate estimation of the flux linkage to be achieved for used in the development of the motor magnetisation characteristics data. The results obtained using the developed permeance model are compared with those derived by other known methods. From the comparison, it is observed that the developed model is capable of producing reliable and accurate output results without having to use any correction factor.