基于模糊决策的电力变压器风险评估方法

Risk assessment method of power transformer based on fuzzy decision-making

针对传统风险评估方法存在评价指标等同对待、当风险优先级(RPN)相等时无法进行评估、评估结果准确性低等不足,提出了基于模糊多准则决策的电力变压器风险评估方法,并成功应用于电力变压器故障模式的风险评估。该方法在对电力变压器进行故障模式及影响分析(FMEA)的基础上,选择发生度、严重度和可检测度作为电力变压器的风险评价指标;采用三角模糊数对3项风险评价指标分别进行模糊化处理,运用熵重法确定各评价指标的权重以表现其相对重要度;通过使用模糊多准则决策理论对故障模式进行排序最终得到风险评估结果。评估实例表明,该方法不仅有效地克服了传统评估方法无法实现评价指标的区别对待和当风险优先级(RPN)相等时无法进行评估这两大不足,而且能有效提高评估结果的准确性。

To solve the problems pertaining to traditional risk assessment methods such as non-differential analysis of evaluation indexes, impossibility of risk evaluation with equal risk priority numbers （RPN） and low accuracy of evaluation results, this paper proposes a risk assessment method based on fuzzy multi-criteria decision-making, which has been successfully employed to evaluate the risk of power transformers. On the basis of the failure mode and effect analysis （FMEA） of power transformer, the occurrence, severity and detectability are chosen as the risk evaluating indexes in this method; the values of these three indexes are respectively fuzzed by using triangular fuzzy number; the weights of the indexes indicating their relative importance are obtained by using entropy method; and the fault modes are sorted by means of fuzzy multi-criteria decision-making; finally, the result of risk assessment can be achieved. The assessment results show that the method not only can effectively overcome the defects of traditional assessment methods that are non-differential analysis of evaluation indexes and impossibility of risk evaluation with equal Risk Priority Numbers, but also can effectively improve the accuracy of the assessment results.