Grid Code Reactive Power Capability Requirement Achievement for Offshore Wind Farms

The increasing diffusion of offshore wind farms (OWFs) represents a challenge for high voltage transmission network operation within specific technical requirements posed by grid codes. Among these requirements, compliance with reactive power capabilities at the point of common coupling is needed for supporting voltage profiles. For this purpose, the proposed procedure focuses on evaluating the optimal amount of reactive power compensation needed to cope with transmission system operator (TSO) grid code requirements for connecting an OWF. The optimisation problem aims to minimise reactive power efforts in the presence of a detailed representation of the network modelled through full AC load flow constraints. The proposed procedure is applied to an OWF connected to the Italian transmission grid (400 kV) via a high- voltage AC link. In addition, the link from the landing point is supposed to be an overhead line or underground cable, depending on possible environmental constraints. The results highlight that remarkable inductive reactive compensation is required for both onshore cable laying options to accomplish the TSO capabilities and that wind turbine regulation makes a considerable contribution to reactive power compensation.