大开距纵磁结构触头磁场特性的数值分析

Numerical Analysis on Magnetic Field Characteristic of Axial Magnetic Field Contacts under Long Break Distance

通过分析几种用于中压真空灭弧室中的触头结构,探讨了将它们应用在高压真空灭弧室中的可能性。并用有限元的方法对单极线圈式和杯状纵向磁场触头结构在大开距条件下的磁场特性进行了仿真计算。采用改变部分触头结构参数的方法来优化磁场分布,在分析计算结果的基础上探讨了将它们应用于高压真空灭弧室中的可行性。结果表明。在大开距条件下即使经过优化,1/3匝线圈式纵磁触头结构和杯状纵磁触头结构所产生的磁场也不足以控制真空电弧,而1/2匝线圈式纵磁触头有较强的纵向磁场,适合于大电流的开断。

Several contact structures for medium voltage vacuum interrupters are analyzed and the feasibility of applying them to high voltage vacuum interrupter is researched. Finite element method based simulation and computation of magnetic field characteristics for two kinds of contact structures, i.e., the coil type of axial magnetic field （AMF） contact structure with one-third turn and cup type of AMF contact structure, under long break distance are conducted. The AMF distribution is optimized by modifying a part of contact structural parameters, and the feasibility of applying them to high voltage vacuum extinction chamber are researched based on results of analytical calculation, Research results show that under the condition of long break distance the magnetic field generated by both above-mentioned contact structures is insufficient to control vacuum arc although a part of contact structural parameters are optimized. The coil type of AMF contact structure with one-half turn possesses more intensive axial magnetic field, so it is suitable to be applied in vacuum interrupters to switch off intense current.