主动解列控制中电网弱连接的一种在线识别方法

An On-line Weak-connection Identification Method for Controlled Islanding of Power System

电网中的弱连接是由电网的拓扑结构和实时运行状态决定的。系统发生机群失稳时,其失步断面将主要分布在这些弱连接线路上。主动解列控制需要在线识别系统的弱连接,并在弱连接上搜索解列断面。从电力系统慢同调理论出发,分析慢模式特征值对线路参数的灵敏度的特征,在此基础上提出一种实用的电力系统弱连接识别方法。推导特征值对于线路参数灵敏度的解析表达式,并基于此设计弱连接识别方法的详细步骤。4机11节点测试系统和华东电网上的仿真实验验证了该方法的有效性。同时,对所提方法在实际工程中的应用模式进行讨论。

The weakly-connected ties in a power system are determined by the system＇s topology and real-time operating state. When cluster instability occurs, the interface among the out-of-step generator groups will mainly distribute among these weakly-connected ties. In islanding control, it is imperative to identify the weakly-connected ties in the system and search for the splitting cut-sets among these weakly- connected ties. Based on the slow coherency theory, this paper analyzed the sensitivity of slow mode eigenvalues to line parameters and proposed a novel method for the identification of weakly-connected ties. The analytical expression of the sensitivity of eigenvalues on line parameters was derived and the detailed steps of weakly-connected ties identification were designed. The effectiveness of this method was demonstrated through case studies on a test system and the East-China grid. Finally, the paper also discussed how to apply the method in practical engineering.