基于GIS中电磁波传播路径特性的局放源定位方法

A Partial Discharge Location Method Based on the Characteristics of the Electromagnetic Wave Propagation Route in GIS

气体绝缘开关设备(GIS)中发生局部放电(以下简称局放)时,为查找绝缘缺陷,需对局放源进行准确定位。超高频(UHF)时差定位法由于原理简单、实现方便、定位精度高等优点获得了广泛应用,但当局放信号的初始脉冲较小而难以确定信号的起始脉冲时间时,UHF时差法将难以有效运用从而导致较大误差。为提高时差定位法的准确性,对局放电磁波在GIS中的传播路径特性进行研究,分析结果表明,局部放电产生的电磁波在GIS中的传播路径与局放源的位置、检测点的位置密切相关,据此提出了基于传播路径的脉冲时差定位法。实验结果表明,当局放源位于GIS外壳附近、电磁波信号初始脉冲很小、难以辨识时,用该方法可以准确定位。

It＇s necessary to accurately locate the partial discharge （PD） source to find the insulation defect when PD happens in the gas insulated switchgear （GIS）. The ultra-high frequency （UHF） based time of flight method is widely used for its merits such as simple principle, easy implementation, and high location acc^lracy. But if the initial pulse of the PD signal is small and blurry, the time of flight method can hardly be applied effectively but will induce rather big errors. To improve the precision of location, the propagation route characteristics of electromagnetic waves excited by PD in GIS are investigated. It is shown that the electromagneticwave propagation route is closely related to the site of PD source and the position of the detector. A PD location method based on the characteristics of the electromagnetic wave propagation route is proposed. Experimental results show that the locating method is precise and effective when the PD source is near the shell of GIS and the initial pulse of the PD signal is very small and hardly distinguishable from background noise.