电气介数及其在电力系统关键线路识别中的应用

Electric Betweenness and Its Application in Vulnerable Line Identification in Power System

提出线路的电气介数并将其用于电力系统关键线路识别。该方法基于电路方程,克服了加权介数模型假设母线间潮流只沿最短路径流动的不足,能有效反映各"发电–负荷"节点对对线路的真实利用情况,其物理背景更符合电力系统特点且可考虑不同发电容量及负荷水平的影响。同时提出系统最大传输能力指标,其变化量同已有指标相结合能更全面地反映系统的故障程度。对IEEE-39系统和西北网的计算表明,高电气介数线路往往属于电网的长程连接,具有关键性地位,且电力系统在针对这些线路的攻击下更为脆弱。对蓄意攻击下系统连锁故障过程的追踪也显示最大传输能力指标的必要性,证明该模型比已有模型更为合理有效。

Electric betweenness and its application in vulnerable line identification in the power system is presented. Compared with weighted betweenness models in which power flow is supposed to be transferred only along the shortest path, the presented model can effectively reflect actual utilization of each line by each ＂plant-load＂ pair with a more comprehensible physical background, in which generation capability and load level in different nodes are also considered. An index of maximal transition capability is also introduced, and it can represent system failures in an all-round way, combined with the existing index of connective loss. Numeric examples of the IEEE-39 and China Northwest system show lines with higher electric betweenness usually belong to long-distance connectings or vulnerable lines system is more vulnerable to of the system, while the power attacks aiming at these lines. Detailed analysis of cascading failures in the IEEE-39 system under prepense attacks also proves the index of maximal transition capability is necessary, and the proposed model is more reasonable and valid than the existing models.