Modular design of permanent-magnet generators for wind turbines

Radial-field, multipole, permanent magnet synchronous machines may be used as direct-coupled generators for large grid-connected wind turbines. Power ratings from below 100 kW to more than 1 MW and pole numbers of 100 to 300 may be required. Modular construction reduces the detailed design effort, and the number of drawings and tools needed. Module designs are presented which can be used for a wide range of machine designs. The rotor modules use standard ferrite magnet blocks. The stator modules are simple E cores each carrying a single rectangular coil. The arrangement eases assembly of the magnetised parts and creates a machine with low reactances and high efficiency