Study of direct-drive permanent magnet synchronous generators with solid rotor back-iron and different windings

Direct-drive Permanent Magnet Synchronous Generators (DDPMSG) are gaining increasingly more attention and application for wind power. This paper presents a comparison among the performance of DDPMSG equipped with three commonly used winding types, integer-slot distributed winding (ISDW), fractional-slot concentrated winding (FSCW) and fractional-slot distributed winding (FSDW). Loss distribution, performance under short circuit fault and temperature rise are investigated and compared using finite element analysis (FEA). The conclusion is helpful for machine designers to choose the proper winding type.