横磁触头真空电弧起始运动的临界触头开距实验研究

起始桥柱状真空电弧运动的临界开距是对应于横磁触头大电流真空电弧运动模式演变的标志性物理量，对横磁触头真空断路器大电流开断性能具有重要影响。本文的研究目标是实验研究横磁触头开槽方式、燃弧时间和电弧电流等因素对横磁触头起始桥柱状真空电弧运动临界开距的影响规律。研究结果显示在燃弧时间0 ms~10 ms、电流有效值5 kA~31.5 kA的实验条件下，3种结构的横磁触头的起始桥柱状电弧有越靠近电流峰值起弧，停滞时间越长的趋势。直角槽型卐字形横磁触头（CuCr40）、螺旋槽型横磁触头（CuCr25）和曲线槽型卐字形横磁触头（CuCr50）的电弧运动临界开距分别在0.96，1.1 mm 和1.7 mm有概率最大值点。相关研究结果对横磁触头大电流真空电弧的发展和演变特性的理解提供基础。

Experimental investigation on the critical contact gap for initial movement of vacuum arcs in transverse magnetic field contacts

The critical contact gap for the initial movement of columnar vacuum arcs is a symbolic physical metric,indicating the evolution of the high-current vacuum arc movement in the transverse magnetic field(TMF)contacts.This parameter has an important influence on the high-current breaking performance of vacuum circuit breakers equipped with TMF contacts.At present,there are limited research on the factors affecting the critical contact gap for the initial motion of columnar vacuum arc during high fault current interruptions in TMF contacts.This paper focuses on the expe-rimental study of the effects of slotting mode in TMF contacts,arcing duration,and arc current on the critical contact gap for the initial movement of columnar vacuum arcs.Results show that,within the arcing time range of 0~10 ms and current values of 5~31.5 kA,the initial columnar vacuum arc in the three kinds of TMF contacts have a tendency of longer stagnation when the arcing onset is closer to the current peak.The critical contact gaps for swastika-type(CuCr40),spiral-type(CuCr25),and curved swastika-type(CuCr50)TMF contacts are discerned to be 0.96mm,1.1mm,and 1.7 mm,respectively.These findings provide a basis for a deeper understanding of the development and evolution of high-current vacuum arcs in TMF contacts.