摘要
GIS中隔离开关在开合短母线时,触头间瞬态击穿将产生VFTO,对设备绝缘构成严重威胁。触头间击穿距离与电弧阻抗特性关联,影响VFTO的时域和频域分布特征。文中为研究GIS隔离开关触头间击穿电弧长度对VFTO波形特征的影响,在GIS隔离开关开合短母线方式1试验中,利用基于电容分压的超宽频电压测量系统准确测量了隔离开关合闸时直流侧全过程VFTO波形,然后提取了前15次预击穿所激发的VFTO波形进行时域、频域以及时频分布分析。通过分析发现,当触头间击穿电弧长度从100mm减小到30mm时,所激发的VFTO时域波形持续时间,以及波头电压突变特征时刻未有明显变化,过冲系数波动的范围变小,对最大过冲系数没有明显影响。触头间距减小时,50MHz以上高频段的特征频点随着电弧长度减小逐渐减少,最高瞬时频率从100MHz降低至70MHz。50MHz以上高频段的频率分量随着电弧长度减小,持续时间变短。当触头间距低于30mm后,20MHz以上高频部分的特征频率发生了明显偏移。通过文中的研究,为进一步优化电弧高频模型和GIS隔离开关结构设计提供了有力支撑。
In case of switching short busbar by GIS disconnector,VFTO will be generated between contacts during the transient breakdown,which poses a serious threat to the insulation of equipment.The breakdown distance be⁃tween contacts is related to the impedance characteristics of the arc,which affects the time and frequency domain dis⁃tribution characteristics of VFTO.In order to study the influence of the breakdown arc length between contacts of GIS disconnector on the waveform characteristics of VFTO,in the test duty 1 of switching short short busbar by GIS dis⁃connector,the ultra⁃widebande voltage measurement system based on the capacitive voltage division is used to accu⁃rately measure whole VFTO waveform of DC side during closing operation of disconnector.Then,the VFTO wave⁃forms excited by the first 15 times breakdowns are extracted for time domain,frequency domain and time⁃frequency distribution analysis.It is found through the analysis that when the length of the breakdown arc between contacts is decreased from 100 mm to 30 mm,the excited duration of time domain waveform of VFTO and the mutation charac⁃teristic time of wave⁃head have no obvious change.The fluctuation range of overshoot coefficient becomes small and has no obvious influence on the maximum overshoot coefficient.In case of reduction of the distance between conatcts,the characteristic frequency point above 50 MHz is gradually reduced with the decrease of arc length,and the maxi⁃mum instantaneous frequency is decreased from 100 MHz down to 70 MHz.The frequency component above 50 MHz is decreased with the arc length and the duration is shortened.After the distance between conatcts is less than 30 mm,the characteristic frequency above 20 MHz has obvious deviation.The research in this paper provides a strong support for optimizing high frequency model of arc and the structure design of GIS disconnector further.
作者
廖钧
丁登伟
刘卫东
何雨峰
易祺
何大猛
何良
LIAO Jun;DING Dengwei;LIU Weidong;HE Yufeng;YI Qi;HE Dameng;HE Liang(State Grid Sichuan Electric Power Company UHV Branch,Chengdu 610016,China;Sichuan Energy Internet Research Institute,Tsinghua University,Chengdu 610213,China)
出处
《高压电器》
北大核心
2025年第8期14-21,共8页
High Voltage Apparatus
基金
国家自然科学基金(51977120)
四川省自然科学基金项目(2024NSFSC0117)。
关键词
GIS隔离开关
开合短母线
特快速暂态过电压
电弧长度
时频特征
GIS disconnector
switching of short busbar
very fast transient over⁃voltage
arc length
time⁃frequency domain characteristics
