Study of microscopic electric field on contact surface in vacuum interrupters based on fractal theory

The objective of this paper is to study the microscopic electric field on contact surface in vacuum interrupters based on fractal theory, with considering the contact surface roughness. Firstly, the fractal theory is introduced into the application of vacuum breakdown studies. The micro-protrusion on the contact surface is modelled based on the W-M fractal function, with the different contact surface roughness 1.6 um and 3.2 um. Then, the electric field distribution in the contact gap is simulated. With considering the amount of calculation time and the accuracy of calculation, multi-zone mesh generation is used to improve the accuracy of the simulation. The results can provide some useful information to study vacuum breakdown phenomena.