纵向磁场作用下大电流真空电弧的机理探讨

STUDY OF THE MECHANISM OF HIGH CURRENT VACUUM ARCS UNDER THE EFFECT OF AXIAL MAGNETIC FIELD

本文以大电流真空电弧为对象,用系统论的"灰匣子"法进行了数学描述,从电弧系统的基本物理方程中导出了模型状态方程组,并通过实验确定方程中的参数。根据导出的状态方程组,讨论了纵向磁场的作用机理、阳极的临界参数及零医判据等问题,从而解释了实验中得到的"L"形曲线所对应的纵磁场负反馈作用及控制过程;解释了阳极轻微熔化时材料参数的调节作用;给出了纵磁场下的电侵蚀率的实验结果。并提出了温度效应对零区的影响,因它是影响弧后介质恢复过程的。

This paper takes high current vacuum arc as an object of study and uses grey-casket method of systematic theory to make mathematical desc- ription.State equations of the model are derived from the fundamental physical equations of the arc system and their parameters are determined by experiments.According to these equations the authors discuss the effect of axial magnetic field,anodic critical parameters and the criterion of zero-zone,etc.Thus the experimental'L'curve and the action of anodic material during slightly melting can be explained.Besides,the paper gives the experimental results of electric erosion coefficient and puts forward the influence of temperature effect on zero-zone which relates to recovery of dielectric strength after arcing.