一起500kV变压器铁芯夹件绝缘异常分析

Analysis of Core to Clamp Insulation Anomaly for 500 kV Transformer

介绍了一起500 kV变压器铁芯对夹件绝缘异常的情况,通过现场的铁芯和夹件接地电流监测发现铁芯和夹件存在环流现象,从而判断铁芯对夹件绝缘异常,经过现场测量、返厂测量和返厂解体,发现了造成异常的原因是铁芯车间工作人员在铁芯打叠完成后将工具遗落所致,并通过电场仿真验证了该结论,最后提出了避免此类事件发生的措施。

Transformer core and clips are all metal materials.In the process of operation,the core and clips are in a changing magnetic field.If the core and clip are badly insulated,the two will form a closed electrical circuit and form a circulation.It increases the transformer loss and cause local overheating phenomenon,which seriously affects the stable operation of the transformer.The design manual requires that the core and clips be well insulated and grounded separately to ensure the safe operation of the transformer.