直流均匀电场下金属微粒运动状态与识别  

Motion state and identification of metal particles in a uniform DC electric field

作　　者：张彬 张周胜 于瑞冬 张馨月 ZHANG Bin;ZHANG Zhousheng;YU Ruidong;ZHANG Xinyue(College of Electrical Engineering,Shanghai University of Electric Power,Shanghai 200090,China)

机构地区：[1]上海电力大学电气工程学院,上海200090

出　　处：《电力科学与技术学报》2025年第1期265-273,共9页Journal of Electric Power Science And Technology

基　　金：上海市科学技术委员会科技项目(20020500800)。

摘　　要：直流气体绝缘封闭输电线路(gas insulation transmission line,GIL)中自由金属微粒在腔体内运动会严重降低气体绝缘水平,极端情况下可能造成局部放电或沿面闪络。为此,对直流均匀电场下金属微粒的运动状态及识别方法开展研究。首先,搭建直流电压下金属微粒运动及超声检测实验平台,通过大量实验记录金属微粒在平行极板间的启举电压、运动轨迹和微粒运动产生的超声信号波形,实验结果表明:正极性电压下线形金属微粒会存在特殊的下极板飞萤运动状态,且线形金属微粒直径越大、长度越长越趋于发生下极板飞萤运动。随后,搭建交流脉冲局部放电实验平台,测量不同状态下金属微粒运动局部放电图谱,实验结果可以验证电晕放电是造成下极板飞萤运动状态的主要因素之一。最后,根据实验装置采集到的金属微粒运动超声信号波形进行去噪处理,提取超声信号3个特征参量并对不同微粒运动状态进行参数对比,结果表明:参数阈值法能够有效区分球形金属微粒的大小及线形金属微粒的运行状态。The movement of free metal particles within the cavity of a direct current gas insulation transmission line(GIL)can significantly reduce the gas insulation level,and in extreme cases,it may cause partial discharge or surface flashover.The motion states of metal particles under a uniform DC electric field and their identification methods are investigated.An experimental platform is established for the movement of metal particles under DC voltage and ultrasonic detection.Through extensive experiments,the uplift voltage of metal particles between parallel plates,their motion trajectories,and the ultrasonic signal waveforms generated by their movement are recorded.The experimental results indicate that under positive polarity voltage,linear metal particles exhibit a unique state of lower plate flying firefly movement,with a higher tendency for this movement in linear metal particles with larger diameters and greater lengths.A partial discharge experimental platform of alternating current pulse is also set up to measure the partial discharge patterns of metal particles in different motion states.The results confirm that corona discharge is one of the main factors contributing to the lower plate flying firefly movement.Noise reduction processing is applied to the ultrasonic signal waveforms of metal particle movement collected by the experimental setup,and three characteristic parameters of the ultrasonic signal are extracted for comparison across different particle motion states.The findings suggest that the parameter threshold method can effectively differentiate between the size of spherical metal particles and the operational states of linear metal particles.

关 键 词：直流气体绝缘封闭输电线路 金属微粒 飞萤现象 超声检测 局部放电 

分 类 号：TM85[电气工程—高电压与绝缘技术]