基于电网剖分与不确定性测度的电网灾难性事件评估

Assessment method of catastrophic accident in power system based on electric network dissection and uncertain measure

针对电网灾难性事件同时受网络结构、电气运行状态以及两者耦合引起的复杂不确定性因素影响造成的评估困难,提出一种综合考虑网络拓扑剖分和电气关系剖分的评估方法,通过拓扑结构剖分和电气关系剖分分别刻画灾难性事件发生过程中的系统固有属性和电气量的变化,揭示出灾难性事件过程中系统结构及其运行特性的规律。该方法基于不确定性理论,从元件受扰动后,系统结构状态和运行状态的不确定性出发,利用可信性测度刻画存在的不确定性以及两类不确定因素耦合产生的复杂不确定性,并以电网负荷损失期望为指标评估灾难性事件。仿真结果表明,该方法对风险最高和最低的灾难性故障的评估结果与传统方法高度一致,而对风险最高和最低之间的灾难性故障的评估结果更符合工程实际。

For the difficulties of catastrophic accident assessment caused by complex uncertainties, network topology and electrical operation state as well as their combination, a new method based on the dissections of network topology and electrical relationship is proposed. These two dissections can describe the inherent properties and variation of electrical parameters in the occurrence process of catastrophic accidents respectively, and can also reveal the patterns of network structure and its operation state. Some assessment measures including credibility measure and expected load loss index are introduced to represent the uncertainties of network structure and operation state after the tripping of some components on the basis of the uncertainty theory. The simulation analysis shows that the assessment results about the most and the least serious contingencies of the proposed method quite agree with that of traditional methods, and it is more accordant to actual power grid operation state according to the assessment of contingencies between the most serious one and the least serious one.