Conceptual design of different winding types for a 20MW wind turbine generator

In this paper, two 20MW wind turbine permanent-magnet generators are separately designed with concentrated windings and distributed windings, based on the same slot fill ratio, magnetic loading and rotor structure to illustrate the overall performance. The generator efficiency and the mass of the two different winding types are then compared for the same temperature limit. Particular attention is paid to the rotor loss and magnet demagnetisation, due to the space harmonics of flux created by the concentrated windings. Conclusions are drawn that whilst concentrated windings can result in a smaller generator, they require additional measures to reduce magnet losses and may require additional magnet mass.