220kV主变压器短路故障分析  

Analysis of 220 kV Transformer Short-Circuit Fault

作　　者：陈志勇 刘晓波 姜华 李月文 张佳羽 CHEN Zhiyong;LIU Xiaobo;JIANG Hua;LI Yuewen;ZHANG Jiayu(Ulanqab Power Supply Company,Inner Mongolia Power(Group)Co.,Ltd.,Ulanqab,Inner Mongolia 012000,China)

机构地区：[1]内蒙古电力(集团)有限责任公司乌兰察布供电分公司,内蒙古乌兰察布012000

出　　处：《东北电力技术》2024年第8期48-53,共6页Northeast Electric Power Technology

摘　　要：某220 kV主变压器发生故障后,低压速断过流保护及差动保护动作,主变压器本体压力突变、轻瓦斯报警、重瓦斯跳闸。瓦斯继电器集气盒中收集到大量特征气体,油色谱分析显示本体油样中H_2、C_2H_2、总烃等超标,且下部油样气体含量高于中部。通过绕组变形测试、变比试验、绕组直流电阻测试与绝缘电阻试验等综合诊断,初步判断为低压侧发生短路故障,在短路电流产生的强大电动力冲击下,低压A相、B相绕组出现变形现象,击穿绝缘纸发生电弧放电,导致匝间、饼间短路及断股,并向内挤压平衡绕组与铁心搭接。结合主变压器返厂解体情况,分析故障原因,验证了保护动作及试验结果的正确性,并提出预防措施,为今后解决同类型变压器故障提供一定参考。After the 220 kV main transformer breaks down,the low-voltage fast-break overcurrent protection and differential protection action,the main transformer body pressure mutates,light gas alarms,and heavy gas trips.A large amount of characteristic gas is collected in the gas relay collecting box.Oil chromatographic analysis shows that H 2,C 2H 2 and total hydrocarbon in the main oil sample exceeds the standard,and the gas content in the lower oil sample is higher than that in the middle.Through the comprehensive diagnosis of winding deformation test,ratio test,winding DC resistance test and insulation resistance test,it is preliminatively determined that the low-voltage side short-circuit fault occurs.Under the strong electric power impact generated by the short-circuit current,the low-voltage A and B phase windings appear deformation phenomenon and arc discharge occurs when the insulation paper is broken down.This causes short circuit and broken strands between turns and cakes,and extrudes the balance winding inward to the core lap.Combined with the disintegration of the main transformer plant,the failure causes are analyzed,the correctness of the protection action and test results are verified,and the preventive measures are put forward.It provides a reference for solving the same type of transformer faults in the future.

关 键 词：变压器 短路故障 绕组变形 油色谱分析 

分 类 号：TM41[电气工程—电器]