基于三相幅值相位关系分析的交叉互联电缆局部放电宽频检测和分析

Broadband Detection and Analysis of Partial Discharge in Cross-connected Cables Based on Three-phase Amplitude-phase Relation Analysis

电力电缆是电力系统中重要的输电设备之一。为减小屏蔽层损耗和降低电缆末端的电压升高,长距离三相输电电缆通常采用交叉互联接地方式。所以,现场检测交叉互联电缆的局部放电时,即会受到外界电磁干扰信号的影响,又会受到三相电缆之间的串扰信号的影响,导致检测结果难以分析判断。为提高现场交叉电缆系统局部放电的有效检测和准确分析,文中采用宽频带检测传感器现场检测了交叉互联电缆局部放电信号,基于放电脉冲波形图、放电PRPD谱图和3PARD谱图,通过分离分类的方法对现场检测结果进行了识别分析。研究结果表明,利用宽频带传感器可获得更多的局部放电信息,有效抑制外界干扰信号;三相幅值相位分析法可有效区分不同相的局部放电信号,排除三相放电信号串扰的影响,从而实现对放电源的识别。

The power cable is one of the most important transmission equipments.The long cable common use the cross bonded grounding method to reduce the loss of shielding layer and decerease the volatge rise at the end of cable.Therefore,it is difficult to diagnosis the PD detection results of cross bonded cable in field because the PD signals will be influence both the enviroment electromagnet interference and the interference among different phases. The broadband sensor is used to detect the PD of cross bonded cable in field in this paper.The waveforms of the PD pulse,PRPD and 3PARD diagrams are analyzed to diagnose the results.The results have shown that the broadband sensor can anti the enviroment electromagnet interference because it can obtain more information of PD signal.The 3PARD diagrams can division the interference among different phases.