正极性先导起始与发展过程中的等离子体特征  

Plasma Characteristics of Positive Leader Inception and Development

作　　者：彭长志 董旭柱 赵彦普[1] 李志军 郑宇 Peng Changzhi;Dong Xuzhu;Zhao Yanpu;Li Zhijun;Zheng Yu(School of Electrical Engineering and Automation Wuhan University,Wuhan 430072 China;State Key Laboratory of Environmental Protection for Power Grid China Electric Power Research Institute,Wuhan 430074 China)

机构地区：[1]武汉大学电气与自动化学院,武汉430072 [2]电网环境保护国家重点实验室(中国电力科学研究院有限公司),武汉430074

出　　处：《电工技术学报》2023年第2期533-541,共9页Transactions of China Electrotechnical Society

基　　金：特高压电力技术与新型电工装备基础国家工程研究中心开放基金资助项目(2021-4201-21-000066)。

摘　　要：先导放电通道由等离子体构成,先导的注入电荷和先导头部温度是用于判断正极性先导起始的关键物理参数。为了获取先导起始的条件及先导发展过程的等离子体特性,该文利用等离子体模型对先导放电通道进行了仿真研究。首先通过10m户外长空气间隙放电综合观测平台,获取了不同冲击电压下的先导放电电流、电压及光学数据。随后利用实测电流数据作为等离子体模型输入,仿真得到了放电通道的温度、等离子体密度、电导率等参数的演变特性。实验及模拟结果表明,先导起始前的触发温度随电压上升率的下降呈现明显的下降趋势。此外,10m空气间隙下,先导起始所需要的临界电荷可低至0.66μC。先导发展过程中的通道温度相对稳定,维持在4000K左右,电子的产生主要源于热电离,放电通道电导率在1~10S/m范围内波动。Long air gap discharge is similar to lightning discharge,which is known as atmospheric plasma.One of the primary processes of long air gap discharge is leader discharge.Despite extensive experimental and simulation work related to leader discharge has been carried out,the conditions for leader initiation remain unclear.In this study,we use experimental data and numerical model to investigate the favorable conditions for leader inception.First,a 10m air gap discharge observation system was built.The observation system includes a high-speed camera,a current measuring device,and a voltage measuring sensor.The high voltage electrode was applied four different rise rate voltages.Using the measured current data,the inception time of the leader discharge can be easily classified.The injected charge for leader inception could be obtained by integrating the current with time.Hence,we obtained the minimum amount of injected charge required for leader initiation at various voltage rise rates.Secondly,the measured current of the 10m discharge gap can be used to simulate plasma discharge process.The key physical quantities that influence channel temperature are the magnitude and duration of the current in the discharge channel.By using the experimental current as the input of plasma model,the gas temperature in the discharge channel could be calculated.Finally,the micro process and luminous properties of the discharge channel during leader development are then examined.The leader discharge current generally fluctuates within a certain range during the leader development process.The plasma model was used to compute the plasma density and conductivity in the discharge channel.Based on the simplified plasma discharge model,the leader formation process of 10m rod plate gap are simulated under different impulse voltage.The evolution laws of the leader channel's streamer stem temperature,conductivity,and thermodynamic parameters are investigated.The main conclusions are as follows:①For the 10m rod plate gap,the first streamer dis

关 键 词：先导放电 等离子体特征 通道温度 注入电荷 

分 类 号：TM853[电气工程—高电压与绝缘技术]