Observation of Discharge Phenomenon on Surface of Semi-conductive PET Films with Lightning Impulse Voltage

Abstract

In recent years, wind power generator is being attracted attention as one of renewable energy. However, lightning damages to blades of wind power generator are increasing with increasing installation of wind power generators, because the wind power generators are installed near the top of mountains and coastlines. Therefore, we considered that the conductive blade surface is effective to protect penetration by lightning strike. We have been recently experimenting with lightning discharge on Semi-conductive PET film by coating one side with conductive polymer. In our previous experiments, creeping discharge occurred on the semi-conductive film surface and hardly penetrated it. In addition, the discharge hardly penetrated even if the uncoated side of the film faces the high voltage side. Therefore, we thought that not directing the coated side of the film to the high voltage electrode is a good way to not change the surface resistance. In this study, we photographed the discharges on the surface of the insulation films having semi-conductivity only on one surface by a high speed camera. As a result, when a negative polarity voltage was applied, the discharge might not penetrate the film in this experiment. It is thought that the film having semi-conductivity prevented the penetration of the negative polarity discharge. In addition, we analysed the propagation of the electrical potential on the film using transient analysis and investigated the reason why the discharge hardly penetrated the film.