GIS内金属性缺陷引起的局部放电超声信号分布特性研究

为研究气体绝缘开关装置(gas insulated switchgear,GIS)内金属性缺陷引起的局部放电超声信号分布特性以及基于分布特性判断缺陷类型的方法,笔者建立了一套超声信号测量系统,并设计了4组GIS内典型缺陷模型,分别是高压导体上尖刺、悬浮电位、绝缘子上微粒和地电极上尖刺。基于该超声测量系统,获取大量超声信号数据。在此大量实验数据基础上,笔者提出了典型参数如超声脉冲数N、超声幅值u、时间间隔Δt和相位Ph及分布谱图N-u、N-Δt和N-Ph区分GIS内典型缺陷的方法,并分析了GIS内金属性缺陷引起的局部放电超声信号分布特性。试验结果分析表明,依据分布模式的GIS内典型缺陷的超声信号统计特性,可区分典型缺陷类型。

Ultrasonic Signal Distribution Characteristics of Partial Discharge Due to Metallic Defects in GIS

To investigate the ultrasonic signal distribution characteristics of partial discharge due to metallic defects in gas insulated switchgear(GIS) and obtain defect recognition method based on the distribution characteristics,an ultrasonic measurement system is constructed.Four models of typical metallic defects in GIS are designed,i.e.tip on high-voltage electrode model,floating potential model,particle on insulator model,and tip on ground electrode model.Plenty of ultrasonic signals are acquired with the ultrasonic measurement system.Based on these data,some methods for recognizing types of typical defects in GIS are proposed by employing four parameters of pulse number N,ultrasonic amplitude u,time interval Δt,and phase angle Ph,as well as g-u,N-Δt,and N-Ph curves.And the ultrasonic distribution characteristics of the metallic defects in GIS are analyzed.Experimental results show that distribution modes of ultrasonic signal characteristics can be used to recognize types of metallic defects.