当前,我国东部部分沿海地区已形成了规模化的新能源发电集群,海上风电场已从长距离放射形接入电网的形式,逐渐发展为登陆后近距离汇聚再接入主网的接线形式。沿用传统单风电场接入系统的无功电压灵敏度方式响应自动电压控制(automatic voltage control, AVC)主站电压指令的运行过程中,易引发局部电网电压异常波动。为此提出了一种风电集群AVC子站无功电压灵敏度协同控制策略。考虑各风电场的交互关系,推导了多种风电集群并网拓扑形式下AVC子站无功电压灵敏度计算方法,并提出了解耦的AVC子站无功电压灵敏度协同控制策略;进一步,具体分析了不同子站无功源出力分配方式下的场内网损。基于MATLAB/MATPOWER平台搭建了三种典型风电集群汇聚模型并对比验证了算法的有效性。算例结果表明,相比传统无功电压灵敏度算法,所提算法能够调节风电集群无功出力以平稳有效应对AVC主站电压指令,在电压偏差指令变化、拓扑结构变化和风电出力水平不同条件下均能够较好地实现各子站并网点电压偏差控制,维持电网电压稳定运行。
英文摘要:
In recent years, more and more East coastal areas in China have formed large-scale renewable power generation clusters, compared with the form of long-distance radial-wiring integration to the power grid, offshore wind farms usually connect with each other near their landing point and then access to the main grid alongside. Applying the traditional single wind farm access system reactive voltage sensitivity way to respond to the automatic voltage control (AVC) main station voltage command regulation is easily triggered by abnormal fluctuations in local grid voltage. This paper proposes a cooperative reactive voltage sensitivity control strategy for clustered wind power AVC substations. Considering the interaction relationship between wind farms, the calculation method of reactive voltage sensitivity of AVC substations is derived, and the decoupled cooperative control strategy of reactive voltage sensitivity of AVC substations is proposed. Furthermore, the power loss under different reactive power output distribution methods is specifically analyzed. Three typical wind power clustering integrated systems are involved and examined to verify the effectiveness of the proposed algorithms based on MATLAB/MATPOWER platform. The example results show that compared with the traditional reactive voltage sensitivity algorithm, the proposed algorithm can regulate reactive power output of clustered wind farms to smoothly and effectively respond to the voltage regulation, and can better realize voltage control of grid-connected points of AVC substations under the conditions of the change of voltage deviation, the change of the topology structure and the different levels of wind power output, so as to maintain stable operation of the power grid voltage.