Modular, permanent-magnet wind-turbine generators

Multipole, permanent-magnet, synchronous machines have been proposed as direct-coupled generators for large grid-connected wind turbines. A manufacturer would need to prepare a wide range of detailed designs and stock a large quantity of parts and materials to cover the range of likely sizes and ratings needed. Modular construction greatly reduces this overhead and brings additional benefits through ease of assembly and repair. The paper illustrates how such a machine can be integrated into a variable-speed system. A modular rotor design using buried ferrite magnets with split pole pieces is described. The magnets can be built up economically from standard 150×100×25 mm blocks. A modular stator core and stator winding are described along with a modular supporting structure and it is shown that this construction leads naturally to a modular approach to the first stage of power conversion for a variable-speed system. The derivation of machine parameters and supporting laboratory studies are reported