Power electronics converters for wind turbine systems

The steady growth of installed wind power which reached 200 GW capacity in 2010, together with the up-scaling of the single wind turbine power capability - 7 MW´s has been announced by manufacturers - has pushed the research and development of power converters towards full scale power conversion, lowered cost pr kW, and increased power density and the need for higher reliability. Substantial efforts are made to comply with the more stringent grid codes, especially grid faults ride-through and reactive power injection, which challenges power converter topologies, because the need for crowbar protection and/or power converter over-rating has been seen in the case of a doubly-fed induction generator. In this paper, power converter technologies are reviewed with focus on single/multi-cell power converter topologies. Further, case studies on the Low Voltage Ride Through demand to power converter technology are presented including a discussion on reliability. It is concluded that as the power level increases in wind turbines, medium voltage power converters will be a dominant power converter configuration.