Discharge Characteristics and Detectability of Metal Particles on the Spacer Surface in Gas-Insulated Switchgears
Discharge Characteristics and Detectability of Metal Particles on the Spacer Surface in Gas-Insulated Switchgears
复制标题
气体绝缘开关设备隔板表面金属颗粒的放电特性及可检测性
DOI：
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发表时间：
2021
影响因子：
4.4
通讯作者：
Dengwei Ding
中科院分区：
文献类型：
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作者：
Xing Li;Weidong Liu;Yuan Xu;Dengwei Ding
绝缘子表面的金属颗粒和污秽污染物被认为是造成突发性闪络的主要因素。了解气体绝缘开关设备中金属颗粒的放电特性和可检测性，将有助于提高其安全性和可靠性。建立了一种基于交叉参考脉冲电流(PC)和超高频(UHF)方法的高灵敏度测量系统。研究了不同长度的金属粒子(Φ=0.5 mm，L=2、5、8、10 mm)在实际间隔棒表面不同位置的局部放电产生的脉冲和超高频信号。得到了隔离物表面金属颗粒的局部放电特性和可探测性，并讨论了检测极限。结果表明，在局部放电试验条件下，对于小于5 mm的颗粒，PD的表观电荷小于1pC，常规的局部放电检测方法在检测间隔棒表面的这些小颗粒时存在局限性。在运行条件下，只有大于8 mm的粒子的表观电荷才能超过1pC，这意味着在野外很难检测到小于8 mm的粒子。然而，结果表明，即使是5 mm长的颗粒物也会对地理信息系统造成危害。同时还发现，检测灵敏度对判断帕金森病严重程度也有很大影响。这一研究对于了解间隔棒表面短金属粒子的局部放电特性、放电水平和可探测性具有重要意义。
Metal particles and dirty contaminants on the spacer surface are mainly considered to be the critical factor in sudden flashovers. Understanding the discharge characteristics as well as the detectability of metal particles in the gas-insulated switchgear (GIS) will be helpful in improving its safety and reliability. In this paper, a high-sensitivity measurement system based on cross-reference pulse current (PC) and ultra-high-frequency (UHF) methods was established. The PC and UHF signals generated by partial discharges (PDs) of metal particles of different lengths (Φ = 0.5 mm, L = 2, 5, 8, and 10 mm) at different positions on a real spacer surface were studied. The PD characteristics and detectability of the metal particles on the spacer surface were obtained while the detection limitation was also discussed. It is found that under PD test condition, the apparent charge of the PDs is less than 1 pC for particles shorter than 5 mm, and the conventional PD detection method have limitations in detecting these short particles on the spacer surface. Under operation condition, only the apparent charge of particles longer than 8 mm can exceed 1 pC, which means it is difficult to detect the particles shorter than 8 mm in field. However, the result indicates that even the 5 mm long particle will be harmful to the GIS. Meanwhile, it is also been found that the detection sensitivity also has a great influence on the judgement of PD severity. This study is of great interest for understanding the PD characteristics, discharge levels, and detectability of short metal particles on spacer surface.