运行中电流互感器二次线圈匝间短路事故成因分析

Cause Analysis of Short Circuit Fault Between Secondary Winding Turns in Operational Current Transformer

针对电流互感器(CT)运行中出现的一例零序保护动作事故及开关柜内二次端子局部烧熔现象,采用直流电阻试验和励磁特性试验对事故原因进行分析,发现CT二次绕组线圈匝间短路是引起零序电流保护动作的直接原因,而运行中CT间歇性开路可能是造成CT二次绕组匝间短路和端子烧熔的原因所在。

Aiming at that a case of zero sequence protective action fault turned up in operational current transformer（CT） and the switchgear in-ternal secondary terminal partial burnt out, this paper adopted DC resistance test and excitation magnetic characteristic test to carry out fault cause analysis, finding that short circuit of CT between secondary winding turns was the direct cause to lead to zero sequence current protective action, moreover the interval open circuit of CT in operation may be the cause to result in short circuit of CT between secondary winding turns and termi-nals burning-out.