基于云理论的电力变压器绝缘状态评估方法

针对电力变压器故障机理复杂,模糊评价隶属函数的确定具有主观性且未考虑随机性,仅凭油中溶解气体单一因素难以有效评估其潜在隐患的问题,提出了一种新的基于模糊云理论的变压器绝缘状态评估方法。建立了绝缘状态评估体系并进行了等级的划分,在用变权动态确定指标权重的基础上,采用隶属云模型描述其模糊性与随机性,并结合红外热像仪与油中溶解气体分析方法对其绝缘状态进行综合评价。通过实例研究,验证该方法有效易行,为变压器状态检修工作提供了一种新方法。

An Assessment Method for Insulation Condition of Power Transformer Based upon Cloud Model

Failure mechanisms of power transformers are complex,and the determination of fuzzy membership function is subjective and fails to take randomness into account.Beside,dissolved gas analysis(DGA) alone does not provide sufficient information to predict potential failures of a transformer.Aiming at these problems,an assessing model of transformer insulation is proposed base upon fuzzy cloud theory.Based on the determination of variable index weights,insulation condition system was established and insulation grade was classified.The cloud model was used to describe the fuzziness and randomness of the transformer and assess the condition of transformer insulation combined with infrared thermal imaging method and DGA method.Case studies and comparison analyses with other assessing method show that fuzzy cloud model analysis method is feasible and effective,and the method also offers a new way of assessment for transformer insulation condition.