XLPE电缆典型缺陷局部放电特性研究

Research on Partial Discharge Characteristics of Typical Defects of XLPE Cable

实时准确地监测电缆内部绝缘缺陷的局放量对电缆状态的评估意义重大。介绍了一种基于新型差分电容传感器的内置局部放电检测系统,该系统可精准测量检测部位的局部放电。同时设计并构造了3种绝缘缺陷模型,分别采用内置式局部放电检测系统和试验室局部放电检测系统对缺陷电缆接头进行局部放电检测,试验结果证明该检测系统与试验室局部放电检测系统的放电相位及相应趋势完全一致,验证了该系统的可靠性。最后分析3种缺陷模型下获得的PRPD谱图,结果表明不同缺陷模型的局部放电信号特征明显,能真实反映电缆接头放电机理,为进一步进行放电类型的模式识别提供了试验依据。

Real-time and accurate monitoring of the partial discharge of internal insulation defects of the cable is of great significance to the evaluation of the cable status.This paper introduces a built-in partial discharge detection system based on novel differential capacitance sensor,which can accurately measure the cable partial discharge at the detection site.At the same time,three insulation defect models are designed and established.The partial discharge of each defective cable joint are measured by the built-in partial discharge defection system and the laboratory partial discharge defection system separately.The test results show that the discharge phase and corresponding trend of the detection system and the laboratory partial discharge detection are completely consistent,which verifies the reliability of this system.Finally,the PRPD spectra obtained under three defect models are analyzed.The results show that the partial discharge signal characteristics of different defect models are obvious,which can truly reflect the discharge mechanism of cable joints,providing an experimental basis for further pattern recognition of discharge types.