考虑风光出力不确定性的电–气互联系统脆弱线路辨识

在电力系统和天然气系统紧密耦合的背景下，任意子系统中任意脆弱线路的扰动或故障都可能会传播到另一个子系统，进而引起整个电–气互联系统的故障。为此，提出一种电–气互联系统脆弱线路辨识方法。首先，提出考虑风光出力不确定性的电–气互联系统协调调度随机优化模型，求解得到电–气互联系统故障前后的运行状态；而后，基于局部集中度和潮流变化熵分别从拓扑结构脆弱性和运行特性脆弱性两方面分析电–气互联系统中线路的脆弱性，构建综合考虑线路拓扑结构脆弱性和运行特性脆弱性的电–气互联系统线路脆弱度指标，对互联系统的脆弱线路进行辨识。通过计算脆弱线路断开后互联系统的测地线脆弱度(geodesic vulnerability)及供需不平衡量，对所辨识的脆弱线路进行评估。6节点电网–7节点气网和24节点电网–20节点气网2个电–气互联系统的算例分析结果验证了所提脆弱线路辨识方法的有效性。

Vulnerable Lines Identification of Integrated Electricity and Natural Gas Systems Considering Wind and Photovoltaic Generation Uncertainties

With the intensified integration of electricity and natural gas system,any disturbance or failure of the vulnerable line in one subsystem may propagate to another system,consequently resulting in a failure of the whole integrated system.To this end,a novel method to identify vulnerable lines of integrated electricity and natural gas system was proposed.Firstly,a stochastic co-optimization model of integrated electricity and natural gas systems considering wind and photovoltaic generation uncertainties was constructed to access the normal and contingency operation conditions of the integrated system.Specially,vulnerability of lines in the integrated electricity and natural gas system was discussed from the point of topological vulnerabilities and functional vulnerabilities via local centrality and power flow changing entropy,respectively.The line vulnerability index,considering both topological and functional vulnerabilities,was constructed to identify vulnerable lines for the integrated electricity and natural gas system.Finally,the geodesic vulnerability and generation/load imbalances were used to quantify influences when the vulnerable lines are out of service.Numerical results of a 6-bus electricity/7-node gas system and a 24-bus electricity/20-node gas system illustrate the effectiveness of the proposed method.