金属突出物电极结构下SF6气体临界击穿场强计算研究  

Study on Calculation of Critical Breakdown Field Strength of SF6 Under Metal Protrusion Electrode Structures

作　　者：赵崇智 罗颜 宋浩永 王邸博 王炜 卓然 黄慧红 ZHAO Chongzhi;LUO Yan;SONG Haoyong;WANG Dibo;WANG Wei;ZHUO Ran;HUANG Huihong(CSG Electric Power Research Institute Co.,Ltd.,Guangzhou 510000,China;Guangzhou Power Supply Co.,Ltd.,Guangzhou 510663,China;United Laboratory of Advanced Electrical Materials and Equipment Support Technology,CSG,Guangzhou 510663,China)

机构地区：[1]广东电网有限责任公司广州供电局,广州510000 [2]南方电网科学研究院有限责任公司,广州510663 [3]南方电网先进电工材料与装备基础联合实验室,广州510663

出　　处：《高压电器》2023年第10期206-214,共9页High Voltage Apparatus

基　　金：南方电网公司科技项目资助(ZBKJXM20190087)。

摘　　要：SF6气体在电力绝缘设备中的应用已经非常广泛,研究SF6气体放电击穿特性对于计算金属突出物电极结构下SF6气体临界击穿场强具有重要意义。文中针对SF6气体在金属突出物电极结构下的放电击穿过程开展了详细的理论研究与计算分析。首先,基于已有的SF6气体击穿过程进行理论总结并加以完善;然后,引入阶段先导发展模型,针对稍不均匀电场条件下SF6气体放电击穿过程进行建模。将放电击穿分为3个主要过程,首电子产生阶段、流注初始阶段及先导发展至击穿阶段;最后,结合气体物性参数建立金属突出物电极结构下SF6气体折合临界击穿场强计算综合模型,计算得到SF6气体在金属突出物电极结构下临界击穿场强。研究表明:相同压强情况下,交流电压下的临界击穿场强要比雷电冲击电压下的折合临界击穿场强低。雷电冲击电压下临界击穿场强极性随电极结构和压强条件的变化而改变。并且,由于在曲率较大处的电极处局部放电产生空间电荷的影响,随着压强的增大和突出物尖端的加长,正极性雷电冲击电压下的临界击穿场强趋向施加交流电压下的临界击穿场强。SF6 gas is used widely in electric insulation equipment.It is of great significance to study the breakdown characteristics of SF6 for calculating the critical breakdown field strength of SF6 under metal protrusion electrode structures.In this paper,detailed theoretical studies and calculation analysis of discharge breakdown process of SF6 under metal protrusion electrode structures are carried out.Firstly,the theoretical analysis and calculation are performed based on the existing SF6 breakdown process.Then,a stage leader development model is introduced to model the discharge breakdown process of SF6 under slightly non-uniform electric field conditions.The discharge breakdown is divided into such three main processes as the first electron generation stage,the streamer inception stage and the leader development to breakdown stage.Finally,a comprehensive calculation model of the equivalent critical breakdown field strength of SF6 gas under metal protrusion electrode structures is set up in combination with the gas properties parameters to obtain the critical breakdown field strength of SF6 gas under metal protrusion electrode structure through calculation.The study shows that under the same pressure conditions,the critical breakdown field strength under AC voltage is lower than the equivalent critical breakdown field under lightning impulse voltage.The polarity of the critical breakdown field strength under lightning impulse voltage varies with the variation of electrode structure and pressure conditions.Also,due to the influence of space charge generated by the partial discharge at the electrode with large curvature and with the increase of pressure and length of protrusion tip,the critical breakdown field strength under the positive lightning impulse voltage tends to be that under the application of the alternating voltage.

关 键 词：SF6 气体绝缘开关 临界击穿场强 流注 先导 

分 类 号：TM213[一般工业技术—材料科学与工程]