Comparison of outer rotor permanent magnet and magnet-less generators for direct-drive wind turbine applications

Interest in using magnet-less switched reluctance generators for wind turbines applications continues to gain popularity. Mainly due to unstable price of the magnet raw material that is one of the main challenges for engineers to forecast the final cost of the wind turbine. This paper presents design of a direct drive switched reluctance generator (DDSRG) for wind turbine applications using Finite-Element Analysis (FEA) tools. The performance, weight, and cost of the proposed DDSRG is compared to a direct-drive permanent magnet generator (DDPMG). The FEA results demonstrate that for the same dimensions, the final cost of the proposed DDSRG is lower when compared to the conventional DDPMG for wind turbine applications. The main drawback of the DDSRG is that it has lower output power than DDPMG for the same dimensions. Also a DDSRG for the same output power as DDPMG has been designed in this paper.