不同因素对真空开关阳极烧蚀影响的仿真研究

Simulation Study About the Influence of Different Factors on Anode Erosion in Vacuum Switch

在大电流真空电弧开断过程中,阳极烧蚀对真空开关的电寿命有重要影响,为了延长触头电寿命,有必要对阳极烧蚀现象进行研究,而建模仿真技术是当前真空电弧研究的一种重要手段。在电弧仿真模型的基础上,建立真空电弧阳极烧蚀模型,计算单次开断对阳极触头的烧蚀,从而得到开断过程中各个因素对阳极触头烧蚀的影响。模型由熔化凝固模块,熔池磁流体动力学(MHD)模块,体积分数法(VOF方法)模块等组成。通过该模型可以得到不同工况下真空开关阳极触头在燃弧过程中的的形变及温度分布。仿真结果表明:开断电流越大,燃弧时间越长,单次开断所造成的阳极烧蚀越严重。开断电流的直流分量越大,单次开断所造成的阳极烧蚀越严重,触头的电寿命越短。

During the breaking of the high⁃current vacuum arc,anode erosion has an important effect on the electri⁃cal endurance of vacuum switch.In order to extend the electrical endurance of vacuum interrupters,it is necessary to research the phenomenon of anode erosion.The modeling and simulation technology are important means for current vacuum arc research.Based on the model for vacuum arc simulation,an anode erosion model is established to calcu⁃late the erosion of the anode contact in a single interruption,obtaining the influence of various factors on the erosion of the anode contact.The model consists of a melting solidification model,a magneto hydro dynamical(MHD)model for molten pool,and the volume of fraction method(VOF).With this model,the deformation and temperature distri⁃bution of the anode contact under different operating conditions can be obtained.The simulation results show that when the breaking current is larger,the arcing time is longer,the anode erosion caused by a single interruption will be more serious.When the direct current components of breaking current is larger,the anode erosion caused by a sin⁃gle interruption will be more serious and electrical endurance of contact will be shorter.