摘要
多级间隙气体开关是高功率微波装置中的关键器件,其中级间绝缘子沿面绝缘强度是影响开关稳定性和寿命的关键因素之一。文中模拟级间绝缘子实际工作条件,对平行平板电极中的圆柱形绝缘子试样施加重频微秒脉冲电压,开展闪络电压、闪络时延以及沿面寿命的实验研究。结果表明:气/固介电常数差异加剧电场畸变,使得闪络电压随着绝缘子材料介电常数增大而降低,SF_(6)中不同材料闪络电压的差异小于空气中;由于累积效应,闪络电压和闪络时延随着重复频率增加整体呈下降趋势;相同欠压比下,绝缘子沿面寿命随着气压升高而增长,SF_(6)中沿面寿命高空气中一个数量级,介电常数较大的材料具有更优异的沿面寿命;SF_(6)与空气闪络路径的差异导致SF_(6)中沿面闪络特性具有与空气中不同的特点,闪络放电分散性低于空气中,重频脉冲作用下材料表面光电发射作用更为显著,连续闪络中劣化猝发等。该研究为级间绝缘子沿面绝缘设计和绝缘材料筛选提供了理论依据。
Multi-gap gas switch(MGS)is the key component of high-power microwave(HPM)system and the surface insulation strength of stage insulators makes contributions to the performance and long-life of the switch.In this paper,in order to accurately simulate the conditions of stage insulators within the MGS,investigations of flashover voltage,time delay and surface insulation lifetime(SIL)under repetitive microsecond pulses(RMPs)were carried out on cylindrical insulator samples under parallel plate-plate electrodes.Our results show that permittivity mismatch between insulators and gas leads to significantly electric field distortion,so that flashover voltage decreases with permittivity increasing,and the difference of flashover voltage in SF_(6) is less than in air;because of cumulation effect,flashover voltage and time delay all decrease with pulse repetition rate frequency(PRF)increasing;at the same applied voltage ratio,SIL increases when the gas pressure increases,SIL in SF_(6) is an order of magnitude higher than that in air,the material with higher permittivity expect to longer SIL;the difference of flashover paths between SF_(6) and air leads to the difference of flashover characteristics:the dispersion of flashover in SF_(6) is less than that in air,photoemission from the surface plays a significant role under RMPs,surface insulation failure occurs suddenly during the process of successive flashovers.The investigation provides a basis for surface insulation design and insulation material selection of stage insulators.
作者
林天煜
李舟
李巍
王雨
王宁
杨兰均
LIN Tianyu;LI Zhou;LI Wei;WANG Yu;WANG Ning;YANG Lanjun(State Key Laboratory of Electrical Insulation and Power Equipment,School of Electrical Engineering,Xi'an Jiaotong University,Xi'an 710049,China;Xi'an Power Supply Company,State Grid Shannxi Electric Power Company,Xi'an 710032,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2022年第12期4780-4790,共11页
High Voltage Engineering
基金
装备预研教育部联合基金(6141A02011608)。
关键词
级间绝缘子
重频微秒脉冲
沿面闪络
沿面寿命
闪络路径
stage insulator
repetitive microsecond pulses
surface flashover
surface insulation lifetime
flashover path
