126kV真空灭弧室3/4匝线圈型纵磁触头大电流电弧特性研究

Study on the Characteristics of High Current Arc of 3/4 Turn Coil-type AMF Contact in 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,采用拉弧试验的方法对其在大电流下的真空电弧扩散态模式持续时间、强电弧模式持续时间以及真空电弧形态等电弧特性进行试验研究。选取3种不同线圈结构的触头进行试验,触头结构1、2、3的线圈宽度分别为12、14、16 mm。试验电流为36 kA(rms)和40 kA(rms),第1个电流半波内的燃弧时间分别为3.5、9 ms。试验结果表明,触头结构2的真空电弧扩散态模式持续时间最长,强电弧模式持续时间最短。随着电弧电流的增加,3种触头结构在电流过零前的扩散态模式持续时间随之减小。通过对2种触头结构大电流真空电弧特性进行分析比较,126 kV真空灭弧室3/4匝线圈型触头选择触头结构2,线圈宽度为14 mm。

The objective of this paper is to experimentally determine the coil width of a 3/4 coil-type axial magnetic field （AMF） contact used in 126 kV vacuum interrupters by comparing the duration of diffuse arc mode, duration of intense arc mode and high current vacuum arc behavior. Three types of coil width are tested in the experiment. The coil width of contact type 1, contact type 2 and contact type 3 is 12 mm, 14 mm and 16 mm, respectively. Arc current is set as 36 kA（rms） and 40 kA（rms）. Arc duration in first current half-wave is set as 3.5 ms and 9 ms. Experiment results show that the duration of diffuse arc mode before current zero of contact type 2 is the longest among the 3 types of contact. The duration of intense arc mode of contact type 2 is the shortest among the 3 types of contact. Besides, with the increase of arc current, the duration of diffuse arc mode before second current zero of each type of contact decreases. Based on the experiment results, the coil width of the 3/4 coil-type contact used in 126 kV vacuum interrupter is determined as 14 mm.