直流電阻測試對變壓器導電回路缺陷的有效性分析
楊新春,羅楊,蔡川,邱煒,黃昆,高紀新
(國網(wǎng)成都供電公司,四川 成都 610041)
摘 要:直流電阻測試對發(fā)現(xiàn)主變壓器繞組缺陷具有重要作用?;趯嶋H案列,分析了直流電阻在發(fā)現(xiàn)主變繞組缺陷的有效性,指出其對發(fā)現(xiàn)套管將軍帽松動、有載分接開關壓接不牢、極性開關內(nèi)部接觸不良等具有明顯效果,但對于因絕緣擊穿導致的斷股類缺陷,只要引線燒損等效截面積所占整體比例不大,則不能反映真實缺陷,只有結(jié)合油色譜、運行工況、保護動作等才能有效判斷故障類型。
關鍵詞:主變壓器;繞組;直流電阻;缺陷
中圖分類號:TM406 文獻標識碼:B 文章編號:1007-3175(2018)04-0048-05
Efficiency Analysis of Direct Current Resistance of Coil Winding to Diagnose Power Transformer Defects
YANG Xin-chun, LUO Yang, CAI Chuan, QIU Wei, HUANG Kun, GAO Ji-xin
(State Grid Chengdu Power Supply Company, Chengdu 610041, China)
Abstract: The direct current (DC) resistance test plays an important part in finding the defects of coil winding in main transformer. Based on some practical examples, this paper analyzed the effectiveness of coil winding defects discovered by the DC resistance test, which was very helpful to the typical defects of transforms, such as flaws on transformer bushing coupler, loose compression splice of on-load tap-changer, bad contact inside polarity switch, poor connection of welding joint, and so on, but for the lines breaking defects caused by insulation breakdown, the real defects couldn’t be reflected as long as the sectional area equivalent to lead burning loss was less percent of the entirety. The only way to effectively judge the fault type is to combine the DC resistance test with oil chromatography, operational states and protective action etc.
Key words: main transformer; coil winding; direct current resistance; defect
參考文獻
[1] 舒劍飛,張建學. 變壓器直流電阻測試實例分析與故障判斷[J]. 電力學報,2010,25(4):321-324.