Surface charge accumulation effect of polyimide after temperature controlling corona polarization

The overall performance of the insulation system will be degraded by surface charge accumulation on insulating materials in Gas Insulated Switchgear (GIS) and other electrical apparatuses. Polyimide (PI) plays an important role in the field of electrical insulation. It is therefore important to have appropriate knowledge on the surface charge decay mechanism of PI polymer. This paper investigated the surface charge accumulation effect of PI polymers and analyzed the relationship between their charge decay tendencies and molecular structures. Furthermore, the surface charge accumulation effect of the samples under different ambient temperature were compared and analyzed. The results show a fact that the decay rate increases when the temperature increases, which is similar with the investigation on polyethylene terephthalate (PET). Besides, it is obvious that high temperature can weaken the accumulation effect of the surface charge on the surface of tested polyimide films.