126kV真空灭弧室3/4匝纵向磁场触头磁场特性及电弧形态研究

Research on Magnetic Field Characteristics and Arc Behaviors of 3/4 Coil-type AMF Contact for 126 kV Vacuum Interrupter

文中针对一种126 kV真空灭弧室3/4匝线圈型纵磁触头,采用电磁仿真分析及拉弧试验方式对其磁场特性及真空电弧形态进行研究。选择3种触头片开槽位置以及3种触头电流连通位置、有无导流排结构,共8种结构进行磁场强度与分布、触头回路电阻的对比,选择当触头电流连通位置对应时,触头片开槽位置在左侧(结构2)与开槽位置在右侧(结构3)的无导流排及有导流排的两种结构进行电弧试验,试验电流为40 k A(rms),燃弧时间为9 ms。分析及试验结果表明,当开槽位置在右边,磁场强度较强且均匀,真空电弧扩散态模式持续时间较。在第2个电流半波峰值时,有导流排的结构的触头之间的电弧集聚更强烈,阳极射流开始形成至阴极区域,真空电弧处于阳极斑点模式。通过对8种触头结构进行分析比较,126 kV真空灭弧室3/4匝线圈型触头选择触头结构3,触头电流连通位置对应,开槽位置在右,无导流排。

The objective of this paper is to determine a 3/4 coil-type axial magnetic field （AMF）contact used in 126 kV vacuum interrupters. The characteristics of magnetic field and the behaviors of vacuum arc are studied by means of electromagnetic simulation and arcing experiment. The AMF distribution and resistance are compared for eight contact plate slots positions and locations, diversion row. Two types of slot positions without the diversion row and one type structure with the diversion row are tested in the arcing experiment. The slot positions of contact type 2 and contact type 3 are left and right, respectively. Arc current is 40 kA（rms）. Arc duration in first current half-wave is set as 9 ms. The simulation and experiment results show that the AMF is higher and more uniform for contact type 3, and it has higher diffuse arc mode duration before current zero. In the second half-wave peak current, vacuum arc is more intense between the contacts with the diversion row, which is in the concentrated mode. The anode jets begin to form and it reach the cathode. The experiment and simulation results show that the 3/4 coil-type contact used in 126 kV vacuum interrupter is determined as contact type 3 without the diversion row, in which the slot position is right and the installation location is that the upper contact corresponds to the lower contact.