Influence of Rotor Overhang Variation on Generating Performance of Axial Flux Permanent Magnet Machine Based on 3-D Analytical Method

This paper presents an analytical method based on transfer relations for an axial flux permanent magnet machine. The method takes the overhang length into account. Although considering the overhang structure is a very attractive way to increase the output power of the machine, optimization of its length has a heavy analytical burden when only the 3-D finite element method is employed for characterization of the electromagnetic field. Therefore, we derive accurate analytical solutions to dramatically reduce the time needed for analysis, and we present an experimental verification using a fabricated sample.