交流送出海上风电场无功配置方案

Reactive power configuration of offshore wind farm transmission system via AC submarine cable

长距离高电压交流海缆送出的风电场接入系统,巨大的海缆充电功率可能导致海缆沿线电压电流波动较大,造成海缆电压越限和过载。在建立海上风电场等值模型的基础上,依据计算海上风电场送出系统在各种工况下无功需求,确定高压电抗器和SVG补偿容量。然后依据并网点电压波动,以并网点无功交换为零为约束条件,计算高压海缆沿线电流分布。鉴于海缆允许的载流量随海缆的敷设方式和敷设环境条件变化,提出依据高压海缆沿线的电流最佳分布确定高压电抗器容量在海上升压站和岸基集控中心分配的方法。文案法应用于某海上风电场的规划设计中,该风电场现已投入使用,其运行情况良好,实践说明提出的无功配置方法是可行有效的。

When a wind farm is connected to the system with a long-distance high-voltage AC submarine cable,the huge reactive charging power of the submarine cable may cause large voltage and current fluctuations along the submarine cable,and may cause the submarine cable to overload and exceed the voltage limit.On the basis of establishing the equivalent model of the offshore wind farm,the compensation capacity of the high-voltage reactor and SVG is determined according to the calculation of the reactive power demand of the sending system of the offshore wind farm under various working conditions.Then,according to the voltage fluctuation of the grid connection point,and the reactive power exchange of the grid connection point is zero as the constraint condition,the current distribution along the high-voltage submarine cable is calculated.Since the current limit of the submarine cable varies with the laying method and environmental conditions of the submarine cable,the distribution of the high-voltage reactor capacity in the offshore booster station and the onshore centralized control center is determined according to the optimal current distribution along the high-voltage submarine cable.The method is applied to the planning and design of an offshore wind farm.The wind farm has been put into use and its operation is good.The practice shows that the reactive power allocation method proposed is feasible and effective.