基于加权秩和比法的电能质量综合评估

Comprehensive power quality evaluation based on weighted rank sum ration method

针对现有电能质量综合评估方法受人为因素影响较大和评估模型较为复杂的问题,提出了基于加权秩和比的电能质量综合评估方法。采用熵值法计算各评估指标的权重。当各评估指标的权重相同时,计算各评估对象的秩和比;当评估指标的权重不同时,计算各评估对象的加权秩和比。利用秩和比或加权秩和比计算各评估对象的概率单位,将概率单位作为自变量代入线性回归方程进行计算,根据计算结果对评估对象进行电能质量的优劣排序和分档。分别采用所提方法、理想解法和基于突变决策理论的方法对某风电场的母线进行电能质量评估并将评估结果进行对比,对比结果表明,所提方法可对各母线的电能质量优劣进行正确的排序和分档。

In order to avoid the complex models and human factors,a method based on weighted RSR（ Rank Sum Ration） is proposed for the comprehensive power quality evaluation. The entropy method is applied to calculate the weight of each evaluation index. For each object to be evaluated,the weighted RSR is calculated when the weights are different,otherwise the RSR is calculated. The probit of each object is calculated with the weighted RSR or RSR,which,as an independent variable,is substitute in the linear regression equation. The objects are sorted and graded according to the calculated results of the equation for power quality evaluation. The power quality of a wind farm is evaluated for its buses by the propose method,the TOPSIS（Technique for Order Preference by Similarity to an Ideal Solution） and the catastrophe decision theory respectively. The comparison of results among three methods shows that,the proposed method sorts and grades the buses properly according to the power quality.