Development of Fractional Slot Axial Flux Permanent Magnet Synchronous Generator with Low Cogging Torque and Reduced Voltage Regulation

분수슬롯을 가지는 축방향 자속형 영구자석 동기전동기의 코깅토크 및 전압리플 저감에 관한 연구

This paper investigated application of fractional-slot concentrated-winding axial flux permanent magnet machines for wind turbines. Design criteria of cogging torque and voltage regulation was firstly proposed for this kind of application. Fractional winding has small cogging torque which is highlight for wind turbines, but slot leakage inductance would increase voltage regulation, which is an important performance index of generators. By varying slot opening, cogging torque and slot leakage inductance could be adjusted. In this paper, cogging torque and inductances were calculated by both analytical and finite element methods. Voltage regulation was studied by two-axis model under unity-power-factor load and verified by transient finite element analysis.