交叉互联高压电缆系统的局部放电在线监测和定位  

On-line Partial Discharge Localization in Cross-bonded HV Cable Systems

作　　者：张磊祺 盛博杰[2] 姜伟[1] 周文俊[2] 田智[1] 董翔 唐泽洋[2,4] 

机构地区：[1]国网湖北省电力公司武汉供电公司,武汉430013 [2]武汉大学电气工程学院,武汉430072 [3]英国格拉斯哥苏格拉大学 [4]国网湖北省电力公司电力科学研究院,武汉430077

出　　处：《高电压技术》2015年第8期2706-2715,共10页High Voltage Engineering

基　　金：中国-苏格兰博士生教育及科研基金(留金欧[2010]6044)~~

摘　　要：高压电缆通常采用三相交叉互联(CB)接地方式来减小金属护套的感应电压和护层电流,由于三相电缆的金属护套通过交叉互联箱进行了换位连接,所以很难确定电缆内局部放电(简称局放,PD)信号发生的具体相位和互联段位。为此,首先通过实验研究了局放信号沿电缆传播时的衰减特性和电缆导体层与屏蔽层间的耦合效应,定量得出了衰减系数和耦合系数。然后以1个完整的交叉互联段为例,建立了仿真模型,研究了当局放源位于不同位置时在不同交叉互联接地箱处的高频电流传感器(HFCT)检测到的局放波形,通过对比分析各个传感器检测到的局放波形发现,局放源位于不同相线、不同电缆段或接头时,这些传感器检测到的信号具有不同的幅值和极性。以此为基础,得出了1套交叉互联高压电缆系统的局放定位规则,利用此规则可对6个传感器检测的信号的幅值和极性进行对比,从而可用来确定局放源的具体相别和段位。In order to reduce grounding circulation, the cross-bonded （CB） grounding method is widely adopted in HV cable systems. As the sheaths of three-phase cables have been transferred through cross-bonding link-boxes, it is difficult to localize which phase of the three phases and which section of a partial discharge （PD） signal have emanated from. For the purpose of solving this problem, we experimentally studied attenuation of PD signals propagating in cables as well as the coupling effect between the conductor and insulation of cables. The corresponding attenuation coefficient and coupl- ing coefficient were obtained. Then a complete cross-bonding cable section was used as an example to build a simulation model, and we used the model to study the partial discharge waveforms of PD source at various places obtained by high frequency current transformers （HFCTs） installed in different cross-bonding link-boxes. Comparison between the wave- forms indicates that the location of PD source corresponds to particular polarity and amplitude of the signals detected by HFCTs. Based on the results, we presented a set of principles for locating PD in cross-bonded HV cable systems. It can be applied to compare the amplitudes and polarities of signals from six HFCTs and determine the section and phase that PD sources locate in.

关 键 词：电缆 交叉互联 局部放电 在线监测 耦合效应 局放定位 

分 类 号：TM75[电气工程—电力系统及自动化]