10 kV喷射式熔断器开断过程数值计算与分析  

Numerical Calculation and Analysis of the Breaking Process of 10 kV Jet Fuse

作　　者：王飞鸣 赵义松 张博 林莘[2] 李冰 徐建源[2] WANG Feiming;ZHAO Yisong;ZHANG Bo;LIN Xin;LI Bing;XU Jianyuan(Elenctric Power Research Institute of State Grid Liaoning Electric Power Supply Co.,Ltd.,Shenyang 110006,China;School of Electrical Engineering,Shenyang University of Technology,Shenyang 110870,China)

机构地区：[1]国网辽宁省电力有限公司电力科学研究院,沈阳110006 [2]沈阳工业大学电气工程学院,沈阳110870

出　　处：《高压电器》2024年第11期191-200,共10页High Voltage Apparatus

基　　金：国网辽宁省电力有限公司科技项目资助(2021YF-51)。

摘　　要：高压喷射式熔断器是电力系统配电网中应用非常广泛的保护电器,研究其燃弧特性对于熔断器可靠运行具有重要意义。文中以10 kV喷射式熔断器为研究对象,首先对熔断器内电场强度进行了三维有限元仿真计算,得到最大电场E_(max)随开距变化曲线;建立考虑烧蚀的二维动态电弧数学模型,计算了熔断器在开断12.5、2.5 kA电流时的电弧特性,对比分析两种电流和不同长度的电弧缩短杆对熔断器内的灭弧管内壁烧蚀质量、气压分布、速度分布的影响;依据流注理论,结合电场和气流场计算结果,得到了熔断器开断短路电流弧后气体的介质恢复曲线。计算结果表明:在电场计算中,最大电场E_(max)在软铜绞线顶端,随着开距的增大而减小,且电弧缩短杆对电场影响较小;12.5 kA开断条件熔断器内的烧蚀质量、整体气压、轴向速度和温度均高于2.5 kA开断条件;电弧缩短杆长度相同时,开断电流越大其介质恢复能力越强;电弧缩短杆在105~155 mm内,加长电弧缩短杆可增强大电流的开断能力,但会减小小电流开断能力。研究结果可以为熔断器电弧熄弧特性分析提供理论依据。High-voltage jet fuse is a kind of protection device which is used widely in distribution network of powersystem,and the study of its arcing characteristics is of great significance for the reliable operation of the fuse.In thispaper,the 10 kV jet fuse is taken as the research object.First,the electric field intensity in the fuse is calculated bythe three-dimensional finite element simulation,and the curve of the maximum electric field E_(max) with the clearance isobtained.A two-dimensional dynamic arc mathematical model considering ablation is set up and calculated.The arccharacteristics of the fuse at the breaking currents of 12.5 k A,2.5 k A are calculated,the influence of two types of cur-rents and arc shortening rods with different lengths on the ablation quality,gas pressure distribution and velocity dis-tribution of the inner wall of the arc extinguishing tube of the fuse is compared and analyzed.The medium recoverycurve of the gas after breaking the short circuit current by the fuse is obtained on the basis of the streamer theory andin combination with the calculation results of the electric field and the gas flow field.The calculation results show thatin the electric field calculation,the maximum electric field E_(max)is at the top of the flexible copper stranded wire,which decreases with the increase of the clearance,and the influence of the arc shortening rod on the electric field issmall.The ablation quality,overall gas pressure,axial velocity and temperature in the fuse at the breaking conditionat 12.5 k A are higher than those at 2.5 k A.In case of same length of the arc shortening rod,the higher the breakingcurrent is,the stronger the medium recovery ability is.When the arc shortening rod is within the range of 105~155 mm,the increase of the length of the arc shortening rod can enhance the breaking capacity of high current,but can reduce the breaking capacity of small current.The research results can provide a theoretical basis for the arc ex-tinguishing characteristics analysis of the fuse.

关 键 词：熔断器 多物理场耦合 烧蚀 介质恢复 

分 类 号：TM563[电气工程—电器]