FEM analysis upon significance of different permanent magnet types used in a five-phase PM generator for gearless small-scale wind

The gearless PM generator system has high potential for the wind turbines because of its robustness, increased energy yield and reliability compared to electrically excited ones. The main disadvantage of PM synchronous generators is the high cost of PMs and the demagnetization risk at high temperature. In this paper is presented a comparative analysis in terms of permanent magnet type chosen for the construction of a five-phase synchronous generator without gearbox, intended to be used on a small scale. The comparison is made taking into discussion both economical and electromagnetic criteria for three types of permanent magnets: ferrite and two rare-earth permanent magnets - SmCo and NdFeB. The analysis is performed using Flux 2D simulation software package, which is based on finite element method, FEM.