基于云理论的高压绝缘子污秽状态风险评估

Risk assessment of high voltage insulator contamination condition by cloud theory

针对绝缘子污秽状态模糊综合评判中只考虑评价指标的模糊性而忽略了评价指标的随机性的特点,提出了基于云理论的绝缘子污秽状态综合评判模型。利用反映绝缘子状态的放电脉冲数、运行年限、气象条件、环境湿度、温度等五个特征参量构建评判指标体系。通过期望值、熵、超熵组成云隶属度函数反映绝缘子污秽状态综合评判等级界限值的模糊性和随机性,实现分级区间软化。利用聚类层次分析法确定主观权重,综合考虑各评判指标的均衡性,对主观权重进行修正得到变权。运用云理论的计算方法得出最终的评判结果。在此基础上定义了置信度系数,使得该模型具有同时给出评判结果和评判结果置信度信息的优点。实际算例分析验证了该模型的实用性和有效性。

According to the characteristics of only considering the fuzziness and ignoring the randomness of evaluation indices for insulator contamination condition fuzzy synthetic evaluation model, a new insulator contamination condition synthetic evaluation model is proposed based on cloud theory. The number of discharge pulse, operation periods, weather conditions, the temperature and the relative humidity are chosen as five characteristic parameters affecting insulator condition, and the evaluation indices system is established. The cloud membership function which is composed of the expected value, the entropy, and the hyper entropy is used to describe the fuzziness and the randomness of the grade limit value for insulator condition synthetic evaluation, which softens the grading range. Clustering analytic hierarchy process is used to obtain subjective weighting, the variable weighting is determined by modifying the subjective weighting based on balancing the evaluation indices. On this basis, the coefficient of credible degree is defined, and the model not only obtains the result of synthetic evaluation but also provides the credibility information of the evaluation result. The practicality and effectiveness of the model is demonstrated by the results of actual numerical example.