真空开关电器中接触触点热过程的仿真研究  

Heat Transfer of Electrical Contact in Vacuum Interrupter:A Simulation Study

作　　者：付思[1] 曹云东[1] 李静[1] 侯春光[1] Fu Si;Cao Yundong;Li Jing;Hou Chunguang(Shenyang University of Technology,Key Lab of Special Electric Machine and High Voltage Apparatus,Shenyang 110870, China)

机构地区：[1]沈阳工业大学特种电机与高压电器教育部重点实验室

出　　处：《真空科学与技术学报》2019年第7期546-551,共6页Chinese Journal of Vacuum Science and Technology

基　　金：辽宁省自然科学基金项目(20180550280)

摘　　要：金属蒸气是真空开关电弧存在的根源,基于流体动力学理论,建立真空开关开断初期分离最终电接触触点由固体、金属液桥到金属蒸气相变过程的完整模型。考虑了金属触点的熔化变形边界,同时关注金属液桥断裂后金属蒸气的扩散过程,计算结果表明电触点最高温度点出现在接触触点的中心,也正是金属桥断裂形成的初始位置。金属液桥相变过程中伴随金属蒸气的蒸发,并在真空环境中迅速扩散,在阴极斑点形成之前,金属蒸气密度高达1.092×10^25m^-3,并沿着扩散半径迅速降低。计算结果表明,随着电极加载电流的增大,金属液桥完全断裂时间大大缩短。The heat transfer,in solid to liquid to vapor phase-transitions of the copper contacts in the initial breaking stage of vacuum interrupter,were empirically approximated,mathematically modeled,theoretically analyzed in classic hydrodynamics and simulated by numerically solving the analytically derived equations.The influence of Joule heating on the physical events,including the melting of solid contact,formation/evolution/rupture of liquid Cu-bridge,and diffusion of Cu-vapor,was investigated.The simulated results show that the hottest spot locates at the waist of liquid-Cu bridge,at which the cylindrical column rapidly shrinks into a dumbbell and ruptures,accompanied by spontaneously evaporation,diffusion and spreading of the Cu-vapor.Before the cathode spot forms,the Cu-vapor density reaches 1.091×10^25m^-3 at the center of the micro-spots,decreasing rapidly because of diffusion between the electrodes.In addition,an increase of the load current significantly shortens the rupture time.

关 键 词：接触触点 金属桥 断裂时间 金属蒸气 

分 类 号：TM561[电气工程—电器]