摘要
为了研究空气间隙放电路径发展的分散性和随机性,分别对棒–棒间隙、棒–双棒组合间隙击穿特性,放电路径选择特性及放电路径发展随机特性开展研究。试验中考虑了下棒电极头部形状和下棒电极布置方式的影响,并通过静电场仿真计算分析间隙电场不均匀系数对50%放电电压的影响,以及下棒电极头部周围静电场强度对放电路径选择特性的影响;同时采用图像处理技术计算了电极表面放电初始发展角θ,以表征高压棒电极表面放电发展随机特性。试验和仿真结果表明:间隙距离为0.4~1.2 m时,间隙电场不均匀系数越大,间隙50%放电电压越低。间隙距离相同情况下,下棒电极头部曲率越大,头部周围场强越大,越容易产生迎面流注,则被击中的概率越大;间隙距离对放电路径选择性有影响,下棒电极头部形状相同的情况下,间隙距离越小,该间隙下棒电极头部周围电场强度越大,越容易产生上行流注,则被击中的概率越大。空气间隙距离增大会减少下棒电极对高压棒电极放电初始发展方向的约束力,高压棒电极头部表面下行流注的发展方向随机性增强。
In order to investigate the dispersion and statistic property of the air gap discharge path, we researched the properties of breakdown voltage of rod-rod gap and rod-double rod gap, the properties of discharge paths selectivity, and the properties of the statistic property of discharge paths. The effect of the rod tip shape and the location of lower elec- trode was considered in the test. The finite element method was employed to calculate the static electric field of the gaps to analyze the test results. Both the effect of electric field uniformity coefficient on 50% breakdown voltage and the effect of electric field intensity of rod tip on the selectivity of the discharge path were analyzed. The initial discharge inception angle 0 of electrode surface was calculated to characterize the discharge statistic properties of high-voltage rod electrode by using image processing technology. Experiment and simulation results indicate that when the gap distance is 0.4-1.2 m, the greater the uniformity coefficient of gap electric field is, the lower the 50% breakdown voltage of gap will be. With the same gap distance, the greater the radius of curvature of rod tip is, the greater the electric field will be. So the streamer more easily occurs and the probability of being hit is greater. Gap distance affects the striking selectivity of discharge path. When the lower rods have the same tip shape, the shorter the gap distance is, the greater the electric field around the rod tip will be. So the streamer more easily occurs and the probability of being hit is greater. The increasing of air gap dis- tance can result in the weakening of attraction of grounded electrode to the initial discharge development of high voltage electrode rod, and it can enhance the randomness of inception direction of downward streamer on the surface of high voltage electrode rod.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2017年第11期3800-3808,共9页
High Voltage Engineering
基金
中国博士后科学基金项目(2014M560624)~~
关键词
50%放电电压
放电路径选择性
电场强度
电场不均匀系数
放电初始发展角
50% discharge voltage
selectivity of discharge path
electric field intensity
the non-uniform coefficient of electric field
angle of discharge path initiation
