基于综合重要度的电网关键线路辨识方法

Method Based on Comprehensive Importance for Critical Line Identification in A Power Grid

更加精准快速识别出电网关键线路,对提高电网运行的稳定程度以及预防电网连锁故障具有重要意义。文章首先基于复杂网络理论提出改进潮流介数指标,从结构角度判别系统受到功率扰动后线路的脆弱程度;然后基于熵理论,提出计及线路负载率的加权潮流转移熵指标,克服原有指标中只考虑转移潮流分布均匀性的不足;最后建立包括以上2种指标的综合重要度评估指标,更加全面地衡量线路在电力系统中的重要程度。通过对IEEE 39节点系统进行仿真,得出了不同攻击方式下系统的改进网络传输效率变化曲线图,证明了综合重要度指标的有效性,对预防电力系统连锁故障具有重要意义。

More accurate and rapid identification of the key lines of power grid is of great significance to improve the stability of the power grid operation and prevent cascading failure of power grid. Firstly,on the basis of the complex network theory,the improved flow betweenness index is proposed to judge the vulnerability of the branch from the structural point of view after the power disturbance. Then,on the basis of the entropy theory,the weighted flow transfer entropy index considering the load rate of the branch is proposed,which overcomes the shortcomings of the original indicator only considering the uniformity of the transfer flow distribution. Finally,the comprehensive importance assessment index including above two indicators is established to more comprehensively measure the importance of the branch in the power system. Through the simulation,the improved network transmission efficiency curve of the system under different attack modes is obtained. The effectiveness of the method is proved by the simulation of IEEE 39-node system,which is of great significance to prevent the cascading failure of power system.