电工技术学报2024，Vol.39Issue(7)：2143-2152,2160,11.DOI:10.19595/j.cnki.1000-6753.tces.230456
大电流真空电弧中阳极熔化过程的实验与仿真研究
Experimental and Numerical Study on Anode Melting in High Current Vacuum Arcs
摘要
Abstract
Vacuum interrupters are widely used in the medium voltage level system with the excellent interruption capability,simple structure and low maintenance cost.Moreover,developing vacuum interruption to transmission voltage level is an ideal method to replace the greenhouse gas SF6 towards the dual-carbon target.Breaking capacity is the core technology of the circuit breaker,the development of vacuum breaking technology needs to be based on an in-depth understanding of its breaking mechanism.In high current vacuum interruption process,the anode melting process under vacuum arc greatly affects the vacuum interruption results.The process of melting and destruction of anodes under the high current vacuum arc has been a focus of research over the decades.However,the previous research on the anode melting mainly focused on copper and copper-based alloys,and the relevant material thermal parameters are relatively limited.In order to understand the anode melting mechanism in a wider range of physical parameters,this work conducted the experiments on the anode melting of W,Mo,Cr and Fe. The objective of this study is to obtain the influence of the anode material on the anode melting,therefore,to eliminate the interference of the arc evolution,the cathode material is set as Cu for the four investigate anode metals.In the experiments,the current is applied from low current to high current with an interval of 1.5 kA.A high speed camera is used to record the anode activity under different arc current.The experimental results show that the corresponding threshold melting current for W,Mo,Cr and Fe are 14.0 kA,11.9 kA,8.6 kA and 7.5 kA,respectively.The first melting of the four metals occurred at the arcing time of about 6.5～7.0 ms. Besides the experiments,this work numerically study the anode melting.A two temperature magneto-hydrodynamic model is used to describe the vacuum arc with a developed cathode boundary.The arc plasma parameters could be obtained in the arc,such as the particle density,temperature,velocity and so on.An anode sheath is considered between the arc column and the anode.The spatial and temporal distribution of the heat flux density delivered to the anode is calculated.The anode input heat is dominated by electron energy,spatially distributed as an exponential function,and temporally varying with arc current.An enthalpy equation is used to describe the anode thermal process.Under the heat source of the input heat flux by arc column,the anode temperature is calculated during the arcing time.The results show that anode temperature first increases rapidly and then decreases slowly.The highest temperature of the four metals occurs around the arcing time of 7.0 ms.The anode thermal process is mainly influence by the heat conductivity,density and specific heat capacity of the anode metals.The simulation results effectively verify the experimental results,and the error between the maximum temperature value calculated under the critical current and the melting point of the corresponding material is less than 150 K. The results of this work clarify the influence of anode materials on the anode melting under a larger range of physical parameters,which is helpful for an in-depth understanding of the contact melting mechanism and provides a basis for contact material selection and development in vacuum switches.关键词
大电流真空电弧/触头熔化/阳极材料/磁流体动力学仿真Key words
High current vacuum arc/contact erosion/anode material/magneto-hydrodynamic simulation分类
信息技术与安全科学引用本文复制引用
张在秦,刘志远,王闯,耿英三,王建华..大电流真空电弧中阳极熔化过程的实验与仿真研究[J].电工技术学报,2024,39(7):2143-2152,2160,11.基金项目
国家自然科学基金项目(52307188)、国家重点研发计划重点专项(2022YFB2403700)和陕西省自然科学基础研究计划项目(2023-JC-YB-398)资助. （52307188）
