微空腔交流放电的光学观测与模型  

Optical Observation of AC Partial Discharge in Micro Cavity and Its Model

作　　者：鲁非[1] 杨楚[2] 叶齐政[2] 

机构地区：[1]国网湖北省电力公司电力科学研究院国家电网公司高压电气设备现场试验技术重点实验室,武汉430077 [2]华中科技大学强电磁工程国家重点实验室,武汉430074

出　　处：《高电压技术》2015年第9期3061-3065,共5页High Voltage Engineering

基　　金：国家自然科学基金(51177059)~~

摘　　要：气泡放电是绝缘领域中的一个重要局部放电现象,大部分研究都从放电的电流信号、特高频电磁波信号等方面进行研究,由于气泡微小尺寸的限制,并没有对放电光学图像进行直接的观察;相关理论模型也都假设放电起始于气泡一端。本论文采用半通孔空穴加工方式在有机玻璃中制作了直径3 mm的微空腔来模拟气泡放电,利用微焦镜头,拍摄了不同焦点位置的放电图像,识别了放电位置和形状。结果表明:放电起始位置不一定在微空腔底部和顶部,而可能在微空腔内壁不光滑的位置;放电路径不一定直接走气隙,而是沿内壁表面;在电压有效值较高时,放电电流信号相位相对集中且没有过零现象。为了克服平板气泡模型的缺陷,提出了更接近物理状况的弧面气泡模型对电流信号不过零现象进行了解释。Cavity discharge is an important partial discharge phenomenon in the field of insulation. Most studies focus on the discharge current signals, ultra-high frequency （UHF） electromagnetic wave signals and other aspects. However, due to the limitation of its small size, the optical image of the cavity discharge phenomenon can not be directly observed. Moreover, some relevant theoretical models also assume that the discharge starts at one end of the cavity. In this paper, a 3 ram-diameter blind hole is machined in the plexiglass and used to model the cavity discharge. By using micro-focus lens, the images with cfifferent focal positions are photographed, a clear discharge phenomenon is observed and the discharge position is identified. The results show that the starting position of discharge is not necessarily in the bottom or the top of the micro cavity, rather, it may also be in the non-smooth position of the micro cavity wall. The discharge path is along the inner surface of the wall, not necessarily through the air gap directly. The collected discharge current signals indicate that the current phase is relatively concentrated and no zero-crossing phenomena under high voltage. In order to overcome the defects of the fiat cavity model, an arc-shaped cavity mode which is closer to the physical condition of discharge in micro cavity, is presented to interpret no zero-crossing phenomena.

关 键 词：局部放电 气泡放电 光学图像 微焦 平板气泡模型 弧面气泡模型 

分 类 号：TM85[电气工程—高电压与绝缘技术]