基于欧式距离法的变压器故障BBA模型建立与分析

针对变压器故障诊断中油溶气体技术的改良三比值法存在故障区域边界值判断模糊的问题,在分析改良三比值法的基础上,以欧式距离来表征隶属每种故障概率大小的形式,建立了不同故障下的基本信任分配函数(BBA)诊断模型进行变压器故障诊断,并采用D-S合成规则对不同故障的BBA进行融合,实现了对多BBA模型函数重新构造以及归一表述的功能。利用该模型对长春某500 k VA变电站的变压器故障进行实例计算,并通过改良三比值法和模糊算法进行对比分析。结果表明:该诊断模型能准确、有效地对变压器的多种常见故障进行诊断;用计算隶属故障概率的形式弥补了改良三比值法边界值计算模糊的缺陷,使故障的判别更加趋于真实准确,为电力变压器故障诊断提供了一种有效的方法。

BBA model establishment and analysis of transformer faults based on Euclidean distance

According to the problem of the improved three-ratio method of dissolved gas analysis which fault area boundary value fuzzy judgment in transformer fault diagnosis , with the analysis of improved three-ratio method , the Euclidean distance is used to represent probability of each failure to establish the basic belief assignment ( BBA) diag-nosis model of different failures for transformer fault diagnosis .And with the D-S synthetic rule fuses the BBA of dif-ferent faults, the function of reconstruction and normalization of the multiple BBA model is realized .By using the BBA model to calculate a transformer fault of 500 kVA substation in Changchun , through the improved three-ratio method and fuzzy algorithm to contrast and analyze , the results show that the model can diagnose a variety of transformer faults accurately and effectively; the form of probability makes up the defect of improved three -ratio method when the boundary value calculation is fuzzy , which makes the criterion of failure is more truthful and accurate .The BBA mod-el can provide an effective method to solve the fault diagnosis of power transformer .