GIS盆式绝缘子表面自由金属颗粒缺陷导致局部放电的发展过程

局部放电是气体绝缘组合电器（GIS）内部绝缘损坏的外在表现。为了研究GIS局部放电的发展规律，在220 kV GIS实验腔体中设置了人工盆式绝缘子表面自由金属颗粒缺陷模型，采用阶梯升压法模拟了该缺陷下局部放电的不同发展阶段，以特高频法对各阶段局放信号进行了测量。基于测量结果，梳理了放电次数、平均放电幅值、总放电幅值、最大放电幅值等的变化规律，从而得出结论：盆式绝缘子表面自由金属颗粒缺陷下局部放电可分为放电初始阶段、放电发展阶段和放电危险阶段，且各放电阶段可用放电特征量及放电散点图的变化来表征。

Partial Discharge Development of Basin-Type Insulator of GIS Triggered by Free Metal Particles Insulation Defect

Partail discharge (PD) of the gas insulated switchgear (GIS) is the outside phenomenon of its insulation defect. In order to study the PD development, an artificial insulation defect model of surface free metal particles on basin-type insulator in an experimental cavity of a 220 kV GIS is set up. The PD development stages under the defect are simulated with step-up voltage method, and the PD signals in each stage are measured based on UHF method. Based on the measured data, the variations of the discharge frequency, the average amplitude of discharge, the total discharge amplitude, and the maximum discharge magnitude are summarized, and it can be concluded that the PD development triggered by the insulation defect of surface free metal particles on the basin-type insulator of GIS can be divided into the initial stage, the developing stage and the dangerous stage.Besides, these stages can be recognized by the discharge characteristic quantity and discharge scattered point maps.