A direct drive permanent magnet generator design for a tidal current turbine(SeaGen)

In this study, the feasibility of a direct-drive permanent magnet generator for a tidal turbine power take-off system, namely MCT´s SeaGen - the world´s first full scale commercial tidal turbine- has been investigated. The investigated PM generator topology is called C-GEN which is an air-cored axial-flux generator developed in the University of Edinburgh. The C-GEN is prior to conventional PM generators by absence of magnetic attraction forces between rotor and stator, absence of cogging torque, ease of manufacturing, modularity and high fault-toleration. Firstly, the integrated analytical design tool that couples electromagnetic, structural and thermal aspects of the generator has been introduced. Then, an optimization tool based on genetic algorithm has been used to maximize the annual electricity generation and to minimize the initial cost of the generator. The optimized generator is validated using FEA tools and the specifications of the generator has been presented.