Study on the surface charge accumulation of post insulators considering Particle's influences in DC GIL

Abstract

Aiming at the problem of conducting particle pollution in DC-GIL, surface charge accumulation on the post-insulator is analyzed based on COMSOL and the platform for surface charge measurement. In this study, two surface charge accumulation models of the post-insulator with particle pollution were established taking the particle pollution, as well as the generating, recombination, migration and diffusion of the positive and negative ions in the gas into account. Based on these models, the impacts of attached particles on charge accumulation are explored by COMSOL, and the effectiveness and correctness of the simulations were verified through the experimental results from the platform. The results illustrate that, the accumulation of surface charge is affected by the conductive particles attached to the surface of the insulator greatly. In addition, the charge surge caused by the particles contact with the electrode is more remarkable, and the charge polarity at the ends of the particle which is located at the middle of the insulator is opposite to the polarity of the electrode. However, the charge polarity at the ends of the particle which is contact with the electrode is the same as the polarity of the electrode. The effect of micro-discharge on charge generation plays an important role on charge accumulation.