Grid-Friendly Connecting of Constant-Speed Wind Turbines Using External Resistors

In this paper an alternative method of connecting fixed-speed wind turbines with active pitch mechanisms or variable-slip generators is proposed and evaluated. Instead of using the conventional soft starter, external resistors are used. The method was evaluated via laboratory tests on a 15 kW machine, as well as theoretically on a 1 MW wind turbine. The proposed method causes smaller grid power quality impact, especially on inductive grids, compared with soft starters. This means that it will be possible to install constant-speed wind turbines to weaker grids utilizing this method.