电流互感器末屏接地异常的影响

Analysis on the Influence of Fault Ground on the End Screen of Current Transformer

电流互感器设备绝缘故障统计数据表明,约20%的故障与末屏断线、末屏接地不良等存在关联,此类故障一旦发生,将导致电流互感器形成对地等效电容,产生对地放电现象,严重时可能导致设备爆炸、人员伤亡等。电力企业需要加强对末屏接地异常故障的重视,在明确接地异常影响的基础上对各类故障原因进行深入分析并制定相应的管控措施。文章对电流互感器末屏接地异常影响进行了论述,总结分析了电容式电流互感器的绝缘结构、电路等效原理,结合常见故障原因提出了试验检测、改造消除等解决措施,并结合两种故障案例为相关单位人员提供参考。

The insulation failure statistics of current transformer equipment show that about 20%of the faults are related to the terminal screen disconnection and poor terminal screen grounding.Once such faults occur,the current transformer will form an equivalent capacitor to the ground,resulting in ground discharge.In serious cases,it may lead to equipment explosion,casualties,etc.Power enterprises need to pay more attention to the abnormal faults of the final screen grounding,analyze the causes of various failures in depth and formulate corresponding control measures on the basis of clarifying the impact of grounding abnormalities.This paper discusses the impact of the grounding abnormality at the end screen of the current transformer,summarizes and analyzes the insulation structure and circuit equivalence principle of the capacitive current transformer.Combined with common fault causes,it puts forward test detection,transformation and elimination and other solutions.Combined with two fault cases,it provides a reference for the personnel of relevant units.