考虑开断相对概率与后果的电网脆弱线路辨识

综合线路开断的相对概率和开断后果，考虑网架拓扑结构及实时运行状态、电源及负荷分布以及线路的传输容量等关键电网信息，给出识别电网脆弱线路的新方法.首先，定义单位熵综合负载率来描述电网的脆弱性，以线路开断前后该指标的变化，并用线路两端节点的重要度对其进行修正，以此来衡量线路开断后果.为合理地评估节点重要度，引入广泛用于网页排序的HITS算法，并对算法进行适应性改进.然后，从线路自身故障率和线路运行时受负荷随机波动影响而潮流越限的相对概率两方面评估线路开断相对概率；给出电网脆弱线路识别流程.IEEE 39算例验证了所提方法合理有效.

Identification of vulnerable lines in power grid consideringrelative probability and consequence of line outage

Considering key information of power grid, such as topology, running state, distribution of power source and load, line flow limit, a new method to identify vulnerable transmission lines was proposed based on relative probability and consequence of line outage. Firstly, comprehensive load rate of unit entropy was defined to represent power grid vulnerability. Change of this index after a line outage was modified by node importance, which measured the consequence of line outage. Hypertext-Induced Topic Search (HITS) algorithm, widely used in web page rank, was modified to evaluate the node importance of power grid. Secondly, relative probability of line outage was calculated considering line failure rate and relative probability of line flow off-limit caused by random fluctuation of loads. Lastly, the specific evaluation process for identifying vulnerable transmission lines was given. Case study of IEEE 39 power system validates that the proposed method is reasonable and efficient.