A streaming electrification model based on differences of work function between solid materials and insulating oil

In order to build highly reliable transformers, it is important to understand the streaming electrification phenomenon. We therefore measured the electrostatic charging tendency of one type of insulating oil flowing on the surface of plates made of several kinds of metal and insulator. From these experiments, it was found that the streaming electrification of insulating oil depended on work functions of solid materials. We then examined our results from the viewpoint of electronic states of insulating oil and solid materials. We then applied a model based on contact charging of polymers.