正极性长空气间隙放电不稳定先导通道温度演化规律研究  

Experimental Study on Temperature Evolution of Unstable Leader Channel in Positive Long Air Gap Discharge

作　　者：程晨 陈维江 贺恒鑫[3] 黄煜彬 傅中 赵爱华 胡丹 CHENG Chen;CHEN Weijiang;HE Hengxin;HUANG Yubin;FU Zhong;ZHAO Aihua;HU Dan(Electric Power Research Institute of State Grid Anhui Electric Power Supply Co.,Ltd.,Hefei 230601,Anhui Province,China;State Grid Corporation of China,Xicheng District,Beijing 100031,China;State Key Laboratory of Advanced Electromagnetic Engineering and Technology(School of Electrical and Electronic Engineering,Huazhong University of Science and Technology),Wuhan 430074,Hubei Province,China)

机构地区：[1]国网安徽省电力有限公司电力科学研究院,安徽省合肥市230601 [2]国家电网有限公司,北京市西城区100031 [3]强电磁工程与新技术国家重点实验室(华中科技大学电气与电子工程学院),湖北省武汉市430074

出　　处：《中国电机工程学报》2024年第15期6238-6247,I0034,共11页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51977090);中国博士后科学基金(2023M740879)。

摘　　要：先导放电是长空气间隙击穿的主导物理过程,是一种高电导率且以热电离过程为主导机制的热等离子体,获取不稳定先导通道温度分布对于揭示先导起始物理机制以及建立先导放电全过程仿真模型至关重要。该文利用脉冲驱动高功率LED光源,建立一套高时空分辨率定量纹影系统,并开展1.0m棒-板间隙正极性先导放电定量纹影观测实验。实测结果表明,在不稳定先导电流持续注入期间,通道轴向温度分布较为均匀,且通道热直径在径向上呈现持续快速扩张,并最终导致不稳定先导放电停止。此外,获得维持不稳定先导放电发展的通道轴线温度临界值为5000K。通过分析发现热传导过程是先导弛豫阶段的主导能量耗散机制,并导致通道轴线温度始终呈现下降趋势,最终稳定在1600K,较暗区通道中心温度稳定值要高。研究对于揭示先导放电物理机制和支撑建立先导放电发展模型具有重要的科学意义和工程应用价值。Leader discharge is the main breakdown mechanism in long air gap.A leader channel is a highly ionized plasma channel dominated by thermal-ionization process.Obtaining the temperature distribution of unstable leader channel has great significance for revealing the physical mechanism of leader inception and whole process modeling of leader discharge.In this study,a quantitative schlieren system driven by high power LED light source is established.The quantitative schlieren observation experiments on positive leader discharge with a 1.0 m rod-plate gap are conducted.Throughout the continuous injection of unstable leader current,the axial temperature distribution exhibits relative uniformity,while the thermal diameter demonstrates continuous and rapid radial expansion.Ultimately,the strong convection loss leads to the termination of unstable leader discharge.Besides,it is found that maintaining the gas temperature in the center of channel at approximately 5000 K is necessary for sustaining the continuous development of leader discharge.It is revealed that heat conduction is the dominant mechanism for energy dissipation during relaxation phase,and the temperature at channel center exhibits a downward trend,eventually stabilizing at 1600 K,which surpasses the stability value during dark period.This research has important scientific significance and engineering application value for revealing the leader discharge mechanism and supporting the establishment of the leader development model.

关 键 词：不稳定先导放电 定量纹影系统 气体温度 热传导 

分 类 号：TM851[电气工程—高电压与绝缘技术]