Study on the effect of wire particle on surface charge accumulation of post insulators in DC GIL

Abstract

Based on the Maxwell equations, surface charge accumulation on the post-insulator was analyzed. The particle pollution, as well as the generating, recombination, migration and diffusion of the positive and negative ions in the gas were taken into account. Furthermore, from the microcosmic perspective, two surface charge accumulation models of the post-insulator with particle pollution were established. Based on these models, the impacts of attached particles and suspended particles on charge accumulation were explored by COMSOL respectively, and the effectiveness and correctness of the simulations were verified through the experimental results from previous researchers. The results illustrate that, the accumulation of surface charge may be affected by the conductive particles attached to the surface of the insulator. In addition, the charge surge caused by the particles attached to the middle part is more remarkable, and the polarities at both ends of the particles are opposite to each other end as well as to the electrodes they approach. As regards the impacts of the floating particles on surface charge accumulation, it can be neglected if the distance between the suspended particle and the insulator surface is more than 4 times of the particle diameter.