变压器状态评价博弈式证据理论模型研究

Study on the Weight Gaming and Modified Evidence Theory Applied to the Condition Assessment of Transformers

变压器状态评价存在大量模糊、不确定甚至是冲突信息,同时现有的评价方法还主要依赖专家的主观经验,这些都阻碍了状态评价进一步的发展。针对以上问题,提出了一种新的评价决策模型,将模糊集理论、权重博弈论和改进证据理论的优点融入到评价方法中来。评价指标体系包括油色谱、电气试验、绝缘油和运行参数4个影响因素共20个评价指标。首先采用模糊集理论获得所有指标的状态隶属度,其次用模糊层次分析法和熵权重方法分别计算各指标的主观权重和客观权重,随后利用权重博弈论结合主观权重和客观权重获得指标的综合权重,最后用改进证据理论将4个因素的评价结果融合,得到变压器的状态评价结果。通过实例验证,该模型可以准确反映变压器的实际状态,为电力公司开展状态评价和安排状态检修工作提供了理论与实践支撑。

The evaluation of transformer status in operation is confusing because of uncertain or even conflicting information.The existing evaluation methods rely mainly on the subjective opinions of experts.This paper proposed a new evaluation model,in which the fuzzy set theory,the game theory and the modified evidence theory were added.The proposed evaluation framework consisted of four levels,including four factors and twenty indices.This method firstly employed the fuzzy set theory to obtain the basic assigned weight of all the indices.Fuzzy hierarchy analysis and the entropy weight method were then adopted to process the basic weight to get the subjective and objective weight of each index respectively.The game theory was utilized to combine the subjective and objective weight to obtain the comprehensive weight.Finally,this paper adopted the modified evidence theory to give the final assessment of transformer.The model was verified by two examples.The results show that the method can predict the actual state of the transformer accurately and provide support for the power company to carry out evaluation and arrange maintenance.