539 / 2017-05-13 12:14:20

Electric Field Enhancement of Vacuum Gap Electrodes Based on Fractal Modeling and Random Surface

Microscopic electric field enhancement; fractal theory; random surface; vacuum breakdown.

It is acknowledged that microscopic electric field enhancement on contact surface in vacuum interrupters (VIs) is fundamental to the electrical breakdown of vacuum gaps according to the different breakdown initiating mechanism, such as the micro-particles initiating mechanism, electric field emission initiating mechanism and so on. The objective of this paper is to investigate the characteristics of microscopic electric field enhancement of vacuum gap electrodes based on the fractal modeling and the random surface under the same condition. In this paper, a 2D model based on the fractal modeling and a 3D model based on the random surface were all established with the applied voltage of 1500 V and the contact gap of 50 um both in the cases of the maximum height of 0.1 μm, 0.3 μm, 0.5 μm and 1 μm. Based on the fractal theory, the electrical field distribution was simulated using Weierstrass-Mandelbrot equation. The random surface was established using a random array as the height of the contact surface. Comparing two different contact surfaces modeling, we can know that the features of the contact surface do have a significant influence on the microscopic electric field of electrodes. The results may provide more information to study the vacuum breakdown mechanism.