The voltage issue for a power system with large-scale wind power integration should be solved from the regional grid perspective by creating a comprehensive control mode of coordinating centralized compensation in some pilot nodes and decentralized compensation in wind farms.So the pilot node selection is becoming the key problem.Based on the electrical relationship between sources and flows of power grids，an approach to pilot node identification is proposed by considering the relevancy among wind farms.This method comprehensively considers the impact of both the relatively static grid structure and dynamic operation state.The main electrical characteristic parameters are obtained by adopting the bidirectional electrical dissection method for use in calculating the index of electrical correlation among wind farms and that of pilot node evaluation. Thus voltage control partitions and pilot nodes are identified.Analysis results from a modified IEEE 39-bus system show that the approach can be used to make rational selection of pilot nodes.