为了了解纵向磁场下的电弧运动过程，建立了真空灭弧室的3维仿真模型。采用PIC模拟方法对12 kV灭弧室内的电磁场、电弧运动特性进行计算仿真。通过改变触头间距、屏蔽罩尺寸和触头开槽宽度，研究了灭弧室内的电场、磁场分布；对不同触头间距下随时间变化的电弧运动过程和触头表面的电弧分布情况进行了模拟计算。计算结果表明：在真空灭弧室中适当设置屏蔽罩，可有效改善灭弧室内的电场分布；触头铜基上的开槽宽度对磁场会产生影响，宽度越大，磁场强度越大。

A three-dimensional model of vacuum interrupter was established to study the arc motion in longitudinal magnetic field. The PIC method was used to simulate the electromagnetic field and arc motion for 12 kV vacuum interrupter. Structural parameters of contact gaps, shield diameters and grooving width of the contact cup were changed to study the influence of the electromagnetic field distribution in vacuum interrupter. Variation of arc motion with time and arc distribution on contact surface under different contact distances were simulated. The results show that the proper placement of shield in vacuum interrupter can effectively improve the electric field distribution, and the grooving width of the contact cup can influence the magnetic field distribution. When the grooving width increases, the magnetic field strength increases.