Role of solid insulating materials in the flow electrification of transformer oils

Date of Completion

January 1993


Engineering, Electronics and Electrical




Flow electrification is the result of the flow of a low conductivity fluid over a solid surface. Past work has focused on a better understanding and the mitigation of this phenomenon, emphasizing only the properties and conditions of the fluid component. In this research, the fundamental electric charge generation process was studied with special emphasis on the role of solid insulating materials.^ The experimental study was performed by means of a streaming potential apparatus. Streaming potential measurements were carried out, under well controlled moisture and temperature conditions as well as oil charging properties. The solid dielectric materials were characterized by means of image analysis, DC conductivity measurement, TDDS, FTIR, and WDX.^ The results showed a linear relationship between streaming potential and pressure drop as predicted by theory. Statistical analysis indicated that the surface roughness significantly affects the streaming potential in the laminar flow regime. The DC dielectric constant does not have an effect on it. Future research is recommended to include materials having a broader range of DC conductivity. ^