中文摘要：

为了更好的研究快脉冲真空闪络,宜选用指形电极结构。通过ANSYS有限元仿真和实验研究指形电极结构对快脉冲下真空沿面闪络特性的影响。仿真计算了相同电极间距d不同电极曲率半径r时指形电极系统的最大电场强度Emax;相同r不同d时指形电极系统的Emax;不同d、r时指形电极系统的场增强因子f。仿真结果表明：d一定时,电极曲率半径r〈8mm时,电极顶端的最大电场强度随着曲率半径的增大而迅速减小,r为8-20mm时,电极前端的最大电场强度变化幅度不大;r一定时,d为1-8mm时,随着d增大,最大场强下降到原来的23%,d〉8mm时,电极前端的最大场强下降趋势有所减慢;电极间距d取值越小,电极曲率半径r越大,场增强因子则越小,对应的电场分布越均匀;对于实验研究用指形电极结构,宜采用r〈8mm,d〉8mm的设计参数。基于18/500ns、峰值输出电压为75kV的快脉冲源以及r=10mm的不锈钢指形电极,研究了纯环氧试样在不同d时的闪络特性。实验结果表明：d为5-15mm时,沿面闪络电压值随d的增加而呈线性增长;d为20-45mm时沿面闪络电压增长缓慢,这与真空间距击穿的关系不同。并结合65/600ns脉冲电压和直流电压下平板电极和指形电极的沿面闪络实验数据,研究了r=10mm,d=10mm时指形电极结构的f,实验得出脉冲电压下f=1.73,直流电压下f=1.47。

英文摘要：

For the pulsed vacuum flashover research, the finger electrode configuration is a better choice. The effect of the finger electrode configuration on surface flashover characteristic under ns pulse in vacuum is investigated by virtue of the ANSYS finite element simulation and the pulse flashover experiments. The effect of the radius of curvature of finger electrode on the maximum electric-field strength with the same electrode gap is simulated. The effect of finger electrodes spacing on the maximum electric-field strength with the same radius of curvature is simulated. The field-enhanced factors of finger electrode with different radius of curvature and spacing are calculated. The simulation results show that： when d is fixed, the maximum electric-field decreases quickly with the curvature radius increases if r〈8 mm, and it chnges slightly if r is 8-20 mm; when r is fixed, the maxiumum electric-field decreases quickly with d increases if d is 1-8 mm, and it decreases slowly if d〉8 mm; the field enhanced factor decreases when d decreases and r increases, and the electric field will be more uniform, r〈8 mm and d〉8 mm are better choice for the real electrode configuration. Flashover studies were conducted using nanosecond pulse of 18 ns rise time and 500 ns full width at half maximum（FWHM）, and the peak output voltage is 75kV. Stainless steel finger electrode with 10 mm curvature radius is used. The flashover properties of pure epoxy sample with different electrode spacing are studied. The experimetal results show that： the flashover voltage increases fastly if d is 5-15 mm, and it increases slowly if d is 20-45 mm, the result is different with that in vacuum. Considering on the flashover data of flat and finger electrodes under pulse（ 65/600 ns） and DC voltage, the field enhanced factors of electrode structure with 10 mm curvature radius and 10 mm electrode spacing are studied. The results are f= 1.73 for pulsed voltage and f= 1.47 for DC voltage.