电力系统脆弱支路及临界割集的辨识

为了克服人为选定割集以及没有考虑故障后系统轨迹的缺点，提出了一种基于支路势能的电力系统暂态稳定最脆弱支路及临界割集的候选集辨识方法，并结合改进的综合指标来辨识临界割集．该方法把故障后电力系统在势能最大值处的拥有最大支路势能的支路作为最脆弱线路，以此线路作为基本线路形成候选集，再根据改进的综合指标来确定临界割集．该方法无需等时域仿真结表后就能确定最脆弱线路及临界割集．仿真研究表明，这种方法N部分计及了故障后系统的轨迹而提高了辨识准确度，辨识速度也由原来的5S缩短为现在的0．35S．

Identification of Weak Line and Critical-Cutset of Power System

In order to overcome the defect produced by manually preparing the candidate critical-cutsets and neglecting the influence of the post-fault trajectory, a method was presented. The strategy of the method is to identify the weak line and form the candidate critical-cutsets for the transient stability of power system first, and then combine with synthesizing index method to identify the critical-cutset. The line whose potential energy is the largest at the peak point of the system potential energy after the fault clearing is considered to be the weakest line, on the basis of which, the candidate critical-cutsets are formed. Finally the critical-cutset is identified by the improved synthesizing index method from the candidate critical-cutsets. The method can determine the weakest line and the critical-cutset at the time when the system potential energy arrives at the first peak point instead of at the end of system simulation. The simulation result of the samples demonstrate that the identification precision was satisfactory, and the simulation time was shortened （ from 5 s to 0.35 s ） .