互联电网动态稳定安控策略优化方法

Optimization method of security control strategy for dynamic stability in interconnected power grid

电网输送断面部分线路断开后,可能引发互联电网的低频振荡问题。紧急降低送端发电机组出力是抑制振荡的有效措施,不同机组控制的效果存在一定差异。发电机的控制系统阻尼及其接入点与受端网络之间的电气距离是影响切机效果的两个重要因素,分别用阻尼贡献和节点电压的相角差对其进行量化,加权后进行切机优先度排序。其中,阻尼贡献指标将电磁力矩中的同步力矩和阻尼力矩解耦,对阻尼力矩的作用进行了分段累加。利用华北电网实际系统进行仿真验证,将所提方法的计算结果与现有安控策略进行对比,证明了所提方法能够优化控制效果,减少控制代价,有一定的实用价值。

It may lead to low frequency oscillation in interconnected power grid if part of the lines of power transmission section is disconnected. Reducing the output of generators in sending end urgently is an effective measurement to restrain oscillation, and different control strategies may lead to different effect. The damping of generators＇ control system and the electrical distance from generator＇s access point to receiving end are the two important factors which impact the effect of cutting machine. The above factors are quantified respectively by damping contribution and phase difference of nodes＇ voltage in this paper, and they are weighted to priority order of cutting machine. The damping contribution accumulates the effect of damping torque segmentally by decoupling the electromagnetic torque to synchronous torque and damping torque. The actual power system of North China is used to verify the correctness of the method. By comparing the existing security control strategy with the calculation result of this proposed method, it shows that the method in this paper can optimize control performance and reduce control cost. Therefore, this method has some practical value.