电力系统灾难性事故的统一不确定性评估方法

为准确刻画电力系统灾难性事故的潜在风险,从灾难性事故的固有物理属性出发,基于不确定性理论提出了电力系统灾难性事故的统一不确定性评估新方法。将灾难性事故看作不确定事件,分别用可信性测度和全局模糊安全指标描述事故发生的可能性和严重性。以N-1事故作为初始事故,通过对每层N-k事故风险指标排序,识别出系统中最可能发生的灾难性事故序列。对WSCC 9节点系统和某地区实际系统进行仿真分析,与传统方法进行了比较,结果证明本文方法更符合系统实际运行情况,具有准确、有效的特点。

United Uncertainty Assessment Method of Power System Catastrophic Accidents

Risk index is a comprehensive measure of possibility and severity of an uncertain failure, which are generally described by component long-term failure probability and severity indices respectively. In practice, due to the time-varying characteristic of component failure probability and the interval feature of its capability to withstand disturbances, several deficiencies indeed exist with the help of a traditional risk approach. Proceeding from the inherent properties of catastrophic failures in a power system, a new method to assess catastrophic failures on the basis of united uncertainty was proposed in this paper. In this method, the notions of credibility measure and global fuzzy security index were developed by taking the united uncertainty of cascading failures into account. The N-k contingency identification was regarded as the calibration standard and the ultimate collapse sequences were obtained through the risk ranking of all contingencies in each simulation layer. As a case study, the WSCC 9-bus system and IEEE 24-bus reliability test system were simulated. Compared with the traditional methods the results have shown that the proposed method is more accordant to actual power system operating states and it is with better accuracy and validity.