基于可拓云理论的电能质量综合评估模型

针对电能质量综合评估中存在不确定性因素的特点,全面考虑电能质量分类等级边界信息的随机性和模糊性,利用云模型的不确定推理特性和可拓学中的物元理论兼具定性、定量分析的优点,提出了基于可拓云理论的电能质量综合评估数学模型。集成层次分析法、熵权法和均方差法确定电能质量各项指标的综合权重值。建立电能质量综合评估标准云物元模型,计算待评物元与标准云物元模型之间的云关联度,引入信息熵理论确定电能质量等级。在此基础上定义了可信度因子,使得所提出的方法在给出电能质量综合评估结果的同时能够提供评估结果的可信度信息。实际算例分析验证了所提出方法的优越性和有效性。

A Synthetic Power Quality Evaluation Model Based on Extension Cloud Theory

Given that some uncertain factors exist in the synthetic evaluation of power quality,a synthetic power quality evaluation mathematical model is proposed based on extension cloud theory.The randomness and fuzziness of the boundary information for power quality classification levels are considered,taking advantage of the uncertain reasoning characteristic of the cloud model and the qualitative and quantitative analysis for the matter element theory.The combination weight of indicator in power quality comprehensive evaluation is determined by integrated analytic hierarchy process method,entropy method and the mean square difference method.A standard cloud matter element model is established for power quality synthetic evaluation.The cloud association degree is calculated between the matter element and standard cloud matter element model.The power quality level is determined according to the information entropy theory.On this basis,the credibility factor is defined,the model not only gives the result of power quality but also provides the credibility information of the comprehensive assessment result.The results of actual numerical example verify the superiority and validity of the new model.