基于穿心特高频传感的开关柜局部放电检测有效性试验

由于开关柜密封性好,以往常用的暂态地电压和超声波局部放电检测技术的有效性和灵敏度受到很大影响。本文提出一种新的局部放电检测技术,通过在带电显示装置信号线上加装特高频电流互感器(ultra-high frequency current transformer,UHFCT),耦合开关柜电气回路中的暂态电流信号,实现开关柜局部放电检测。在实验室搭建了基于开关柜带电显示装置的试验平台,设置了典型局部放电缺陷,采用UHFCT、高频电流互感器(high frequency current transformer,HFCT)、脉冲电流检测阻抗、特高频传感器(ultra-high frequency sensor,UHFS)等多种手段同时进行局部放电检测。对比发现,UHFCT检测效果优于HFCT和UHFS,其有效性和灵敏度得到充分验证。在开关柜中进行试点应用,UHFCT监测到典型局部放电信号。

Experiment on the Effectiveness of Partial Discharge Detection in Switchgear Based on UHF Sensing

The sensitivity and effectiveness of the commonly used partial discharge detection technology such as transient earth voltage(TEV)and acoustic emission(AE)have been greatly affected due to the good sealing performance of switchgear.A new partial discharge detection technology is proposed in the paper,an ultra-high frequency current transformer(UHFCT)is installed on the live display device of switchgear,to couple high-frequency transient signals in the electrical circuit.A test platform based on live display device is set up and typical partial discharge defects are set.UHFCT,high frequency current transformer(HFCT),detection impe-dance and ultra-high frequency sensor(UHFS)are used for PD detection.It's found that UHFCT detection is effective and sensitive,its results are better than HFCT and UHFS.Pilot application is also carried out in actual operation switch cabinet,and typical partial discharge signals are detected by UHFCT.