基于期望损失指标的电力系统故障筛选和排序

为了避免在故障筛选与排序中只考虑故障的严重程度，提出了一种新的故障筛选和排序的方法。它是以动态安全域的求解为基础，以故障的期望损失作为筛选和排序的指标，同时考虑故障发生时电力系统的经济性与随机性两个方面，更符合实际情况。首先，根据经验故障集，用小范围解析法计算电力系统发生故障时的动态安全域，从而求解发生故障时的改进的概率不安全指标和期望损失，根据故障在故障集中的比例筛选出期望损失比较大的故障线路，将其放入筛选集中。然后，根据误差比例控制曲线，控制计算动态安全域的精度，重新计算筛选集中电力系统发生故障时的动态安全域、期望损失和它们所占的比例，依据此比例进行排序。通过IEEE10机39节点系统算例验证了该方法能够快速、全面、准确地实现故障的筛选与排序。

Contingency screening and ranking based on dynamic security region of the power system

In order to avoid only considering the severity of the fault in the screening and ranking, a new contingency screening and ranking method is proposed. It is based on the calculation of the dynamic security region and expected shortfall is the indicator of contingency screening and ranking. It takes account into the economy and randomness of the power system when fault occurs, so it accords to the actual situation. First, according to experience fault sets, we can calculate dynamic security region of power system by analytic method of small range when the fault occurs, then calculate the improved probabilistic insecurity index and expected shortfall. According to the proportion in the fault sets, we can screen fault line that the expected shortfall is relatively large, then put these fault lines into screening sets. Then, according to the curve that ratio is controlled by error, we can control the accuracy of the calculation of dynamic security region and recalculate dynamic security region of power system, expected shortfall and the proportion when the fault occurs. We can have fault ranking according to the proportion. Case studies on New England 10-machine 39-bus system show that the proposed method can realize the contingency screening and ranking quickly, fully and accurately.