基于磁场闪络抑制原理，研究了由回路电流产生的同轴自磁场对径向真空固体绝缘界面沿面闪络特性的影响规律。根据同轴结构电场E和磁场B的比值与半径无关、只与电路参数相关的特点，分别设计了E/cB(c为光速)为0.041，0.05，0.056和0.062的四种同轴电极结构，开展了有磁场和无磁场两种条件下电介质的真空沿面闪络实验研究。实验结果表明，在有利于磁场闪络抑制条件的自磁场位形下，真空沿面闪络耐压水平相比无磁场情况有明显提高，且比值E/cB越小闪络电压提高幅度越大。当E/cB比值为0.041时，沿面闪络电压可提高约1.3倍；而当自磁场位形反向时，沿面闪络电压相比于无磁场情况有所降低。

The coaxial self-magnetic field generated by pulsed current of low impedance generator could affect the vacuum insulator surface flashover characteristics because of the magnetic-flashover-inhibition (MFI) effect. In coaxial electrode structure, the ratio of electric field E and magnetic field B is independent of variety of radius, but only depends on circuit parameters. Four coaxial structures are designed with different ratios of E/cB, viz., 0.041, 0.05, 0.056, and 0.062. Two type experiments, with and without magnetic field, are carried out. The experimental results show that, the surface flashover voltage with appropriate magnetic field orientation to MFI is increased obviously, compared to that without magnetic field. The smaller the ratio of E/cB is, the higher the flashover voltage is. When the ratio of E/cB is 0.041, the flashover voltage can increase to about 13 times that in non-magnetic field condition. But flashover voltage will decrease when the orientation of magnetic field is reversed.