基于潮流相关性网络的电网脆弱线路识别

Identification of Vulnerable Lines in Power Grid Based on Power Flow Correlation Network

国内外大停电事故表明,电力系统中的脆弱线路会带来极大的运行风险,直接导致系统安全性下降.鉴于此,本文根据二级连锁故障发生时有功潮流的转移特征进行电力系统脆弱线路识别.首先,从系统运行角度,以电力系统发生二级连锁故障时有功潮流的转移量为系统线路间关系进行赋权,并构建双向加权潮流相关性网络;随后,为量化线路在连锁故障中的脆弱性,提出一种基于改进E指数的脆弱线路识别方法.研究表明:针对IEEE-39节点系统,依据本文方法识别结果中前8条脆弱线路的平均风险价值指数和平均条件风险价值指数分别为3 453.73 MW与187.82 MW,远高于其他方法所得结果;静态蓄意攻击后所得的系统剩余负荷率仅为43.4%,系统子电气岛数量快速增长.

Global blackouts have indicated that vulnerable lines in the power system would bring great operation risk and threaten system security.In view of this,the identification of vulnerable lines in the power system was carried out according to the transfer characteristics of the active power flows in the case of a two-stage cascading failure.First,from the perspective of system operation,the relationship between the lines was weighted in terms of the transferred active power flows when the power system had a two-stage cascading failure,and a bidirectional weighted power flow correlation network was constructed.Then,an improved E-index-based identification method for vulnerable lines was proposed to quantify line vulnerability in cascading failures.The results show that the average value at risk and the average conditional value at risk of the top eight vulnerable lines in the identified results are 3 453.73 MW and 187.82 MW respectively for the IEEE-39 bus system,which are much higher than those obtained from other methods.Meanwhile,the residual load rate of the system is only43.4% after the static intentional attack,and the number of power islands in the system increases rapidly.