110 kV线路故障造成220 kV变压器跳闸的事故分析  

Analysis of 220 kV Transformer Trip Caused by 110 kV Line Fault

作　　者：程昭龙 张亚宁 CHENG Zhaolong;ZHANG Yaning(State Grid Heze Power Supply Company,Heze 274000,China)

机构地区：[1]国网山东省电力公司菏泽供电公司,山东菏泽274000

出　　处：《山东电力技术》2020年第11期62-66,共5页Shandong Electric Power

摘　　要：短路容量不足易导致变压器抗短路能力大幅下降,若变压器所供下级线路出口发生永久性短路,较大的故障电流产生的电动力易造成变压器内部绕组变形,进而导致变压器跳闸。针对一起110 kV线路故障引起上级变压器跳闸事故,通过分析事故前后的变压器运行方式、保护动作情况以及故障变压器的油色谱,并利用频率响应、短路阻抗分析法分别测量变压器直流电阻与短路阻抗。根据试验数据分析验证故障变压器绕组变形,进而证明变压器所供下级线路故障会降低变压器的抗短路能力,对变压器的设计要求、调度运行、事故处理及抗短路能力提高提供参考。Insufficient short-circuit capacity can easily lead to a large reduction in short-circuit resistance of transformers.If permanent short-circuit occurs at the outlet of the lower line supplied by the transformer,the electrodynamic force generated by large fault current can easily cause transformer internal winding distortion,which leads to transformer tripping.In view of a power transformer tripping accident caused by a 110 kV line fault,the operation mode of transformer before and after the accident,protection action and oil chromatogram of the transformer in fault are analyzed,and the DC resistance and short-circuit impedance of the transformer are measured by frequency response and short-circuit impedance methods respectively.Based on the analysis of test data,the winding distortion of the faulty transformer is validated,which proves that the faults of the lower line supplied by the transformer can reduce the short-circuit resistance of the transformer.It provides reference for the design requirements,dispatch operation,accident handling and how to improve the short-circuit resistance of the transformer.

关 键 词：变压器 短路容量 抗短路 频率响应分析 调度运行 

分 类 号：TM153[电气工程—电工理论与新技术]