Flow electrification of transformer oil

Polymer blended and polymer coated insulations in large oil-cooled power transformers are the most recent advances in modern technology. The consequences of the type of solid insulating material; which in contact with the streaming oil, and combined electric and magnetic fields on the electrostatic charging tendency (ECT) of oil are the principal aims of this paper. ECT of transformer oil is experimentally investigated using different types of oils, and solid insulating and electrode materials. All solid dielectrics used show quantitative as well as qualitative changes in oil electrification especially at low temperatures. In addition under combined electric and magnetic fields, when increasing the magnetic field, the conduction current decreases but the streaming current increases.