中文摘要：

快速精准地辨识电网电压薄弱节点并执行相应的控制措施，是预防电力系统电压失稳的一项重要工作。首先，在原有电力系统电压稳定局部指标L指标的基础上，通过对Ⅱ型等值支路模型列写潮流方程，考虑支路潮流方程解存在性的原理推导出静态电压稳定Lq指标和Lp指标。然后分析了Lq指标和Lp指标的不足，通过列写支路电压方程，考虑支路电压方程解存在性原理改造得到改进指标Lpqu。最后，本文分析了2种支路方程下所提指标的优劣，结合了支路潮流方程和支路电压方程，提出一种基于支路方程可行解域的电压稳定Lu.p指标，使其可以快速识别系统中的薄弱支路。以新疆某地区实际电网为例，分析验证了所提指标对电网薄弱点快速识别的精确度和线性程度，对调度人员可以快速准确识别系统中电压薄弱节点具有重要的指导意义。

英文摘要：

It is an important task for the prevention of voltage instability of the power system to identify the weak nodes of grid and take corresponding quick and accurate control measures. First of all, the static volt- age stability Lq and Lp index are deduced on the basis of L index of voltage stability local index of original power system and through writing on the PI equivalent branch power flow equation model and also with consideration of existence principle of branch flow equation. Then, the deficiency of the Lq and Lp index is analyzed. The improvement index Lpqu is obtained through writing branch voltage equation and considering modification of existence principle of branch voltage equation solution. Finally, the advantage and disadvan- tage of the proposed index under two kinds of branch equation are analyzed,the voltage stability Lu.p index based on a kind of branch equation solution is proposed with combination of the branch flow equation and branch voltage equation so to keep them identify the weak branch of the system. In this paper, an actual power network at certain area of Xinjiang is taken as an example to analyze and verify the fast identification accuracy and linearity of the proposed index to the weak point of power network and has a guidance signifi- cance of the dispatching personnel in fast and accurate identifying the weak point of the voltage of the system.