基于负关联度的DGA故障诊断分析  

Dissolved Gas Analysis Based on Negative Relational Grade

作　　者：宋斌[1] 刘志雄[1] 李恩文[1] 王国利 

机构地区：[1]武汉大学电气工程学院,湖北省武汉市430072 [2]特高压工程技术(昆明、广州)国家工程实验室,广东省广州市510080

出　　处：《电网技术》2015年第9期2627-2632,共6页Power System Technology

基　　金：特高压工程技术(昆明、广州)国家工程实验室开放基金资助(NEL 201412)~~

摘　　要：三比值法是电力变压器进行潜伏性故障诊断的有效方法之一,但该方法存在缺码问题,并且对位于比值边界附近的数据易造成误判。在对大量溶解气体分析(dissolved gas analysis,DGA)数据整理分析的基础上,发现同种故障类型的数据之间,H2、CH4、C2H6、C2H4、C2H2这5种故障气体变化折线具有较强的相似性,即对同种故障的2条数据,从一条数据到另一条数,5种故障气体之间倾向于同时增加或者同时减小,而不同故障类型的数据之间,折线容易出现相反的变化,相似性差。以此规律为基础,对已有的斜率关联度进行分析探讨,对其所能刻画的斜率区间过窄的问题进行了改进,构建了负关联度计算方法,采用该方法定量分析故障气体折线的相似性,并进行故障诊断。该方法摒除了比值法的思想,保留了DGA的全部信息,能对变压器故障进行判断识别,在一定程度上克服了三比值法的缺码问题,以及在边界附近误判的问题。该方法为DGA分析提供了新的思路。实例验证了该方法的有效性。Three-ratio method is an effective way to detect the latent faults for power transformer. But the defect of code absence exists in this method and chromatographic data that near the coding boundaries is likely be misdiagnosed. Based on large number of dissolved gas analysis（DGA） data collected from journal articles, this paper finds that the change rule of gas contents for H2、CH4、C2H6、C2H4、C2H2 are same if the chromatographic data belongs to the same type of fault. From one date to another, the contents of the five gases go up or go down together. If they don’t vary uniformly, the chromatographic data belong to different kinds of faults. Based on this rule, in this paper the relation degree of slop coefficient is explored, a new relational degree calculation method is built, in which the slope range of the relational degree is improved. With the newly build relation degree of slop coefficient the gases varying rule is analyzed quantitatively and faults diagnose is performed. Break away from the ratio approach, this diagnostic method keeps the entire original DGA message, can detect the latent faults for power transformer and overcome the defect of three-ratio method mentioned above. This method has provided a new approach for DGA. The validity of the method is verified by cases.

关 键 词：溶解气体分析 三比值法 关联度 故障诊断 

分 类 号：TM85[电气工程—高电压与绝缘技术]