220 kV 高压预制式电缆中间接头故障分析与处理

Fault Analysis of 220 kV High － voltage Prefabricated Cable Joint and Its Treatment

摘要:

以某 220 kV 高压电缆中间接头在试送电、交流耐压试验过程中多次发生绝缘击穿的异常现象为研究对象，对 比分析了接头内的放电通道和施工工艺等问题。故障接头解体后，基于放电通道均起始于导体接续管外的半导电带 边缘处、均存在沿面放电等特征，认为供应商在关键部位变更产品的施工工艺，即绝缘预制件的扩径方法、导体接续 管外的处理工艺，造成产品安装后无法达到设计性能，是造成本次事故的主要原因。

Abstract:

The insulation breakdown of 220 kV high － voltage prefabricated cable joint，which occurs several times during the trial line charging and AC voltage withstand test process，is analyzed． The comparisons of discharge channels，installation procedures etc． are done to find out the main reason of joint faults． After the disassembly of broken － down joints，similar features are found． Discharge channels starts at the edge of semiconducting band which is winded around the metal connecting pipe， and surface discharges on the main insulation of cable are found in each broken － down joint． The installation procedure in critical parts is found to be changed，such as the expanding process of prefabricated cable joint and the treatment process of metal connecting pipe． Based on these phenomena，it is concluded that the change of installation procedure in critical parts， which leads to poor performance of the prefabricated cable joint after installation，is the main reason of insulation breakdown．