多直流馈入电网动态无功补偿选点实用方法

A Practical Site Selection Method for Dynamic Reactive Power Compensation in Multi-Infeed DC Power Grid

为合理选择动态无功补偿装置的安装点以提高多直流馈入电网的电压稳定性,根据多直流馈入电网存在电压凹陷区的特征以及主导节点的机理,提出基于电压灵敏度的无功补偿安装效果评估指标及其计算方法,并确定了指标中直流权重的定义及其计算方法。建立了基于时域仿真计算,对动态无功补偿安装区内站点进行无功投入效果指标循环排序,确定安装点的流程。将所提方法应用于远景江苏规划电网,计算得到动态无功补偿选点方案,通过与其它方案的安全稳定计算结果比对,结果表明,在同等容量的动态无功补偿配置下,推荐方案可以更好地提高系统电压稳定性,证明了该方法的正确性和实用性。

To reasonably select the sites to install dynamic reactive power compensators to improve the voltage stability of multi-infeed DC power grid, in accordance with the feature that there exists voltage sag area in multi-infeed DC power grid and the mechanism of dominant nodes, the voltage sensitivity based indices and corresponding computational method are proposed to assess compensation effect of the installed reactive power compensators, and the definition of DC weight in the indices and its computing method are also determined. A time-domain simulation and computation based flow chart to determine the sites to install reactive power compensators, which cyclically orders the indices of compensation effects of compensators located at the substations within the region to install dynamic reactive power compensators, is decided. The proposed method is applied to perspective long-term plan of Jiangsu power grid and a dynamic reactive power compensation scheme is attained. Comparing the security and stability calculated by the attained scheme with those computed by other schemes, the comparison results show that under the configuration of dynamic reactive compensators with the same capacity, a better system voltage stability can be achieved by the scheme obtained by the proposed method, thus, both correctness and practicality of the proposed method are proved.