220kV电缆接头半导电尖端缺陷的局部放电试验

Partial Discharge Pattern of Semi-conductor Layer Tip Defect in 220 kV Cable Joint

交联聚乙烯电缆系统(尤其是电缆附件)故障,大多归因于生产制造和安装工艺不当导致的局部缺陷。因局部放电与放电源有着密切的关系,局部放电检测和模式识别被广泛用作获取缺陷类型及严重性信息的重要手段,以期为电缆系统的检修或更换决策的制定提供技术依据。为研究现场安装工艺不当造成的超高压电缆接头绝缘缺陷,在实验室内实际制作220 kV交联聚乙烯电缆接头半导电尖端人工缺陷,并且构建内置电容耦合传感器,在屏蔽良好的实验室大厅内进行局部放电试验。试验研究结果显示,接头内半导电尖端缺陷导致电场畸变明显,不同电压等级下的放电特性谱图具有明显特征,并采用二维小波变换提取q-φ放电谱图特征,为高压电缆线路局部放电状态检测放电谱图的诊断提供了缺陷样本数据。

Partial discharge（PD） detection and pattern recognition have been widely accepted as a means to provide information on both the type and severity of defects or potential failures,which is further expected to give advice on repair or replacement of cable accessories.In order to research insulation defect due to on-site poor workmanship,we experimentally researched the partial discharge on 220 kV XLPE cable joint with semi-conductor layer tip defect by the method of internal capacitive coupling sensor.Research results show that semi-conductor layer tip defect can easily lead to electric field concentration,PD patterns of different applied voltage show obvious characteristics,which can be utilized as samples for further on-site PD pattern recognition.