Voltage Control Strategy of Offshore Wind Farms Under HVAC Integration Mode

Nowadays offshore wind power is developing rapidly. However, the large charging power of AC submarine cable (SC) can cause many problems, such as over-voltage and over-current along the SC, and over-voltage on the high-voltage side of offshore booster platform, which cannot be effectively controlled only by unilateral control of the onshore power grid through the point of common connection (PCC). Therefore, in this paper, a voltage control strategy for offshore wind farms is put forward, which considers the voltage characteristics along the SC. Firstly, the typical structure of the offshore wind farm AC transmission system is analyzed, and a simulation model of the system is built in PSCAD/EMTDC. Then, with the traditional unilateral control strategy, the reactive characteristics along the SC of different lengths are studied and the demand of voltage control is obtained. On this basis, a voltage control strategy of offshore wind farms is proposed. Finally, the feasibility of the strategy is verified through simulation analysis.