Influence of rotor tooth shape on air-gap magnetic field in Homopolar Inductor Alternator

A simplified 2D computed model is presented in order to investigate the influences of the geometry parameters of rotor tooth on the air-gap magnetic field of Homopolar Inductor Alternator (HIA) by using Finite Element Method (FEM). The results show that the fundamental air-gap flux density depends on the width and height of the rotor tooth. Given that the polar pitch in HIA is 90° mechanical angle, a more sinusoidal field distribution is obtained when the rotor tooth width is equal to 40°angle. And a larger fundamental component of the air-gap flux density is yielded when the rotor tooth height is at least 16 times long than the air-gap radial length.