线路故障引起电压凹陷的频次最大熵评估

实际电力系统中，线路故障点受诸多因素影响，具有随机不确定性。针对其随机规律难以直接计算的问题，提出利用最大熵原理评估线路故障引起的电压凹陷频次新方法。该方法综合考虑不同线路故障类型，首先利用解析式法确定线路故障区间，然后直接以故障区间样本数据的统计矩作约束条件，通过最大化熵，提取线路故障点的客观概率分布，并结合线路故障率评估得到母线电压凹陷的频次。文中阐述新方法的应用背景及实现原理，并对IEEE-30节点标准测试系统进行仿真分析，与传统故障点法比较，新方法不受舍入误差影响，仿真结果证明该方法的准确性、适应性及推广性。

Voltage Sag Occurrence Frequency Assessment Caused by Line Faults Using the Maximum Entropy Method

In power system, fault location that influences voltage sags is randomly distributed determined by many factors. Due to the problems of being difficult to calculate its occurrence pattern, a new stochastic method based on maximum entropy principle to assess the occurrence frequency of voltage sags caused by line faults was proposed in this paper. Considering synthetically different line fault types, based on fault intervals set by analytical approach and sampled data moment of fault intervals, the method was to extract the objective probability distribution of line fault points by maximizing the entropy and the occurrence frequency of voltage sags in the site of bus by combining fault rate. The new method was proposed including its application background and implementation principle and had been applied to the IEEE 30-bus reliability test system with the results characterized by no influence of round-off errors, more accuracy, adaptation and wide application compared with the traditional fault point method.