Hierarchical control scheme for coordinated reactive power regulation in clustered wind farms

Coordinated reactive power regulation is always a critical issue when it comes to a system with a high penetration level of wind energy. This study provides a distributed control scheme for wind farm reactive power regulation, aiming to coordinate the reactive power reference among wind farm clusters. Within the limited communication among neighbouring clusters, fair reactive power generation sharing is achieved. Moreover, the reactive power capability of the wind turbine (WT) is utilised to cooperate with reactive power compensation devices. The characteristics of the collector system are analysed to improve the voltage profile. Instead of averagely assigning the generation order to each WT, the reference is assigned based on voltage sensitivity. Case studies are carried out to validate the performance of the proposed control scheme.