基于模糊层次分析法的电能质量综合评估与灵敏度分析

Power quality comprehensive evaluation and sensitivity analysis based on fuzzy analytical hierarchy process

电能质量是电力系统运行质量的重要组成部分。在现有的电能质量综合评估方法中,通常根据专家的知识和经验来确定指标权重,而专家的有些经验更适合用模糊方法来描述。在此背景下,采用模糊层次分析法(FAHP)对电能质量进行综合评估。首先,根据国家电能质量标准及相关规定构建了电能质量评价指标体系。之后,构造了基于三角模糊数的互补判断矩阵,并通过计算三角模糊数期望值的方法得到指标权重,然后用层次分析法对取自不同电能质量监测点的监测样本进行综合评估和排序。在此基础上,提出了基于FAHP的灵敏度分析方法,用于分析指标权重和指标值的变化对电能质量综合评估结果的影响,得到了导致不同电能质量监测样本排序发生变化时对应的所有指标值及指标权重的临界值,可用以引导供电公司和用户采取合理的供用电决策。最后,以一个10 kV配电系统为例对所提出的方法做了说明。

Power quality represents an important component of power system operating performance. In the existing methods for power quality evaluation, the weights for various evaluation indices are usually specified by domain experts, while the knowledge and experience of experts are better described by fuzzy sets. Given this background, the welt-es- tablished fuzzy analytical hierarchy process （FAHP） is applied to evaluate power quality in specified monitoring buses, and a complementary judgment matrix based on triangular fuzzy numbers emp]oyed. Then, the expected values of trian-gular fuzzy numbers are employed to define the weights of indexes. A sensitivity analysis method is next presented to examine the impacts of the values and weights of indices on the comprehensive evaluation results. And the sensitivity intervals which may lead to the change of the sorting results of power quality evaluation are obtained and can help both power supply companies and customers to respectively make reasonable decisions on supplying and consuming electrici-ty. Finally, a distribution system with a 10 kV voltage level is served for demonstrating the developed method.