一种现场带电处理铁芯多点接地的方法  

A Method to Deal with Multi-point Grounding of Iron Core on Site

作　　者：朱玲 李春先 Zhu Ling;Li Chunxian(ABB Zhongshan Transformer Co.,Ltd.,Zhongshan,Guangdong 528449,China)

机构地区：[1]中山ABB变压器有限公司,广东中山528449

出　　处：《机电工程技术》2021年第6期307-309,共3页Mechanical & Electrical Engineering Technology

摘　　要：变压器在现场运行过程中,铁芯多点接地的情况比较常见。当铁芯有2点或以上接地后,铁芯的主磁通附近存在短路环,将在短路环内形成短路电流或不稳定连接引起间断的电弧放电,从而导致油中故障气体迅速增加,影响变压器的安全运行。铁芯多点接地的处理方法通常需要返厂吊芯处理才能从根本上解决。在用户的用电需求不容许变压器断电返厂维修的情况下,从限制铁芯多点接地电流出发,提出了在铁芯与地之间增加一个串联电阻,减少铁芯多点接地电流,从而实现在变压器不断电的情况下处理现场运行变压器的铁芯多点接地故障。在现场运行一台变压器中的实践证明,该方法可以大大降低铁芯多点接地电流,使变压器油中气体的增长速率趋于稳定,保证变压器在现场提供持续供电。During the operation of the transformer in the field,it is common for the iron core to be grounded at multiple points.When the iron core is grounded at 2 or more points,there is a short-circuit ring near the main magnetic flux of the iron core,which will form a short-circuit current or unstable connection in the short-circuit ring and cause intermittent arc discharge,which will lead to a rapid increase of fault gas in the oil and affect Safe operation of transformers.The treatment method of multi-point grounding of the iron core usually requires returning to the factory and lifting the core to solve it fundamentally.When the user’s power demand does not allow the transformer to be returned to the factory for maintenance,starting from limiting the multi-point grounding current of the iron core,it was proposed to add a series resistance between the iron core and the ground to reduce the multi-point grounding current of the iron core.In this way,the multi-point ground fault of the core of the on-site operation transformer can be dealt with under the condition of uninterrupted power supply of the transformer.The practice of running a transformer on site has proved that this method can greatly reduce the multi-point grounding current of the iron core,stabilize the growth rate of the gas in the transformer oil,and ensure that the transformer provides continuous power supply on site.

关 键 词：铁芯多点接地 串联电阻 油中故障气体 

分 类 号：TM41[电气工程—电器]