在真空开关的开断过程中,外部母线和导电杆所形成的"U"型回路会在极间电弧区域产生横向磁场(transverse magnetic field,TMF)。横向磁场的存在会影响真空开关的开断性能,通过仿真对这一影响进行了初步的探索。基于真空电弧二维磁流体动力学模型及阳极熔化凝固模型,大电流真空电弧(high current vacuum arc,HCVA)在TMF和电极系统自生纵向磁场共同作用下的电弧参数分布及阳极温度分布得到了揭示。仿真结果中,HCVA在TMF的影响下会产生明显的偏移,并且各项参数都有所变化;阳极温度分布也会产生同样的偏移,最终使得阳极熔化也发生偏移。这些变化会对真空开关的开断产生不利影响,特别是离子密度的增大使得电流过零时极间残留等离子体增多,降低开关的开断性能。
In the breaking process of vacuum switch, "U" type loop formed by external bus bar and conducting rod will generate a transverse magnetic field(TMF) in interelectrode zone. The existence of TMF has influence on interruption ability of vacuum switch, this article concentrates on the influence and carries on a preliminary simulation research. Based on 2D magnetro-hydrodynamics(MHD) model of vacuum arc and anode melting and solidification model, plasma parameter distribution and anode temperature distribution of high current vacuum arc(HCVA) under combined action of TMF and axial magnetic field(AMF) are obtained. In the simulation results, HCVA under the influence of TMF has an obvious deflection, and plasma parameters have some changes; anode temperature generates the same deflection, and so do anode melting area. Those changes have bad influence on interruption of vacuum switch, especially the rising of ion density will cause the increasing of residual plasma density when the current crosses zero, this will decrease the interruption ability of vacuum switch.