Reactive power management and control of distant large-scale grid-connected offshore wind power farms

Reactive power management and control of distant large-scale offshore wind power farms connected to the grid through high-voltage alternating current (HVAC) transmission cable are presented in this paper. The choice of the transmission option is based on the capacity of the considered wind farm (WF) and the distance to the onshore grid connection point. The WF is made up of identical doubly-fed induction generators (DFIGs). Modelling and improved analysis of the effective reactive power capability of DFIGs as affected by various operational constraints are provided. In addition, modelling and analysis of the reactive power demands, balance, and control are presented. The minimum capacity and reactive power settings for reactive power compensation required for the system are determined. Possibility of unity power factor operation suggested by the German electricity association (VDEW) is investigated. A summary of the main outcomes of the work presented in this paper is provided in the conclusions section.