计及无功潮流影响的传输介数概念及其电网关键线路辨识研究

在潮流介数的基础上，考虑了线路在传输无功潮流方面的作用，提出线路传输介数并将其用于辨识电网关键线路。由于充足的无功支持是电压稳定性的基础，将无功传输的作用纳入到关键线路辨识方法中后，传输介数能准确地辨识出影响系统电压稳定性的重要线路。关键线路的连续故障会导致有功和无功传输通道的破坏，需要切除部分负荷以维持系统频率和电压稳定，故采用基于最优潮流的失负荷量作为故障线路重要性的评价指标，以验证具有高传输介数的线路在电网运行中承担关键作用。IEEE39和IEEE118节点系统算例表明，传输介数能够辨识出系统中影响节点电压稳定水平的重要线路，其辨识效果优于潮流介数，基于传输介数的电网关键线路辨识方法具有合理性和有效性。

Study of the concept of transmission betweenness considering the effect of reactive power flow and its application in identification of critical lines in power grid

Based on flow betweenness, transmission betweenness puts into consideration the role of a line in transmission of reactive power. Transmission betweenness is proposed and applied into identification of critical lines in power grid. Since abundant reactive power support is the base of voltage stability, transmission betweenness considering the effect of reactive power flow can identify critical lines that are important to voltage stability. Successive faults of critical lines can destroy transmission corridors of active and reactive power flow. On this occasion, some loads have to be cut off to maintain frequency and voltage stability. So, load shedding based on optimal power flow is calculated as the evaluation index to verify that transmission lines with high transmission betweenness are critical indeed in power grid. The results of IEEE 39-bus system and IEEE 118-bus system show that transmission betweenness is superior to flow betweenness in identification of critical lines that influence voltage stability, and the identification method of critical lines in power grid based on transmission betweenness is reasonable and effective. This work is supported by the National Key Research and Development Program of China (No. 2016YFB0900100), and Science Technology Program of State Grid Zhejiang Electric Power Company (No. 5211SX1500R4).