Discharge characteristics of leader inception and development under 10 m long air gap—experimental observation and simulation results  

作　　者：Changzhi Peng Xuzhu Dong Yanpu Zhao Zhijun Li Yu Zheng Xuekai Pei Lei Liu Bing Luo 

机构地区：[1]School of Electrical Engineering and Automation,Wuhan University,Wuhan,China [2]State Key Laboratory of Environmental Protection for Power Grid,State Grid Corporation of China,Wuhan,China [3]Electric Power Research Institute,China Southern Power Grid,Guangzhou,China

出　　处：《High Voltage》2023年第6期1151-1160,共10页高电压（英文）

基　　金：supported by the National Engineering Research Center of UHV Technology and Novel Electrical Equipment Basis(2020‐4201‐21‐000066).

摘　　要：The physical mechanism of leader formation and development is not well understood.In this study,we present experimental and simulation results obtained with a 10 m long air gap discharge.A 10 m outdoor discharge experiment is carried out to obtain the current,voltage,and optical image during the leader discharge process.Four different impulse voltages were applied to the rod‐plane gap.The measured current is used as an input for a plasma model,then the temperature and electric field could be calculated.The simulation results show that the temperature of the streamer stem during the dark period may exceed 2000 K.In addition,the critical charge required for leader initiation can be as low as 0.27μC for a 10 m air gap.The channel temperature is relatively stable in the process of leader development,which is maintained at about 4500 K.The electron density is about 0.5–3�1020 m-3,and the discharge channel conductivity fluctuates in the range of 1–10 S/m for the leader current between 1 and 2 A.A long dark period is tended to be associated with a higher injected charge by the first streamer.It is inferred that the voltage increments during the dark period play an important role in promoting streamer‐to‐leader transition,except for temperature and the injected charge.

关 键 词：DISCHARGE characteristics maintained 

分 类 号：TM83[电气工程—高电压与绝缘技术]