Abstract
Forced convection of insulation oil is the main heat transfer mode in large power and ultra high voltage (UHV) transformers. The electrification risk caused by friction between mineral oil and pressboard has been suspected to be responsible for several failures. The electrification measurement was carried out in a rotation system. The influences of oil temperature, rotation speed, time, and applied electric field of fresh and dry transformer oil have been investigated by a measurement system, respectively. A comparison between these results has been made, and the related theory can be used to explain the physical and chemical processes which take place on the interface between the oil and pressboard. The results from the rotation system indicate that interface charge density increases with the increase of the pressboard thickness, rotation time and speed. The electrification phenomenon can lead to reduction of the breakdown strength of the oil/pressboard. It is concluded that some effective measures should be taken to restrain the possible harm caused by the streaming electrification in UHV converter transformer.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
