Assessment of the suitability of ferrite magnet excited synchronous generators for offshore wind turbines

In recent years the use of permanent magnets (PM) for wind turbine generators has increased significantly. The large price fluctuations encourage us to look at alternative PM materials. The main purpose of this paper is to assess the suitability or otherwise of a ferrite magnet excited synchronous generators for offshore wind turbines. Here, a generator design (for a 6 MW offshore turbine) using ferrite magnets is presented and compared with a generator using NdFeB magnets, in terms of capital costs, efficiency, and cost of energy. In order to do this a ferrite magnet generator is designed and compared to a design of a generator of the same rating that uses surface mounted NdFeB magnets.