基于潮流介数的电力系统关键线路辨识

Identification of Critical Line in Power Systems Based on Flow Betweenness

提出线路潮流介数并将其应用于电力系统关键线路的辨识。该方法基于系统当前运行方式和潮流分布,克服了以往(加权)介数指标假设节点间功率按最短路径传输和忽略线路潮流具有方向性的弊端,能有效反映和量化线路在发电机到负荷功率传输中发挥的作用,同时考虑了发电机和负荷间最大可用传输功率对线路关键性的影响,其物理背景更加符合电力系统实际。同时,在反映关键线路故障对电力系统状态造成影响方面,提出采用层次分析法分析关键线路故障对系统线路过负荷、节点电压越限和暂态稳定性等方面造成的综合影响,验证利用潮流介数指标辨识出关键线路的相对重要程度。CEPRI 36节点数据和甘肃电网实际运行数据的仿真结果表明,所提关键线路辨识方法能够更好地反映线路在整个电网中的重要程度,验证了潮流介数在电力系统关键线路识别中的正确性和有效性。

Power flow betweenness and its application in vulnerable line identification in the power system are presented. Compared with （weighted） betweenness models in which power flow is supposed to be not directional and transferred only through the shortest path, the presented model bases on current operating mode and flow distribution, can effectively reflect and quantify actual effect of each line by ＂plant-load＂ pair with a more comprehensible physical background, in which maximum available transmit power between generator and load is also considered. Meanwhile, to reflect the impact of the critical line fault on the power system, analytic hierarchy process （AHP） is presented to evaluate transmission line over-load, voltage-limit, and transient stability level comprehensively. The Evaluation results are more objective and close to power system characteristics. Numeric examples of the CEPRI36 and Gansu power system show critical line identification method proposed in this paper can better reflect the degree of importance of the line in the entire power grid, and the correctness and effectiveness are verified.