Design of 10 MW low inductance PM generator for direct drive offshore wind turbine

Direct drive permanent magnet synchronous generators (PMSG) in wind turbine applications are becoming increasingly popular due to their reliability compared to medium speed generators with a gearbox. A proposed generator-drive scheme with reduced active switching provides a way to reduce the power electronics cost significantly. This requires the per unit reactance (Xpu) of the generator to be low compared to conventional generators. Three PMSG topologies were designed, optimized and analyzed for their performance for this 10 MW direct drive generator-drive system. Optimization of these generator topologies for their efficiency and weight was performed. Comparisons between them for the efficiency, weight, Xpu, and cost are presented. Once the design is selected, integration of generator-drive system, challenges and results are also discussed and presented