Title :
Discharges in combined transformer oil/paper insulation
Author :
Berg, Gunnar ; Lundgaard, Lars E.
Author_Institution :
SINTEF Energy Res., Trondheim, Norway
Abstract :
Discharge signatures and breakdown levels have been recorded for combined transformer oil/impregnated paper insulation subjected to AC high voltage. Different electrode geometries have been studied, varying from the point-plane gap to a semi-homogeneous sphere-plane configuration. At high moisture levels discharge activity was monitored at an average electric field below 1 kV/mm, with breakdown occurring 6 kV/mm. Characteristic discharge patterns were identified for corona, wedge, void and creeping discharges, but depend strongly on applied voltage, time and moisture content of the insulation
Keywords :
corona; electric breakdown; impregnated insulation; moisture; paper; transformer oil; AC high voltage; applied voltage; breakdown levels; combined transformer oil/paper insulation; corona; creeping discharges; discharge activity; discharge patterns; discharge signatures; discharges; electrode geometries; high moisture levels; impregnated paper insulation; moisture content; point-plane gap; semi-homogeneous sphere-plane configuration; void discharges; wedge discharges; Breakdown voltage; Corona; Electric breakdown; Electric fields; Electrodes; Geometry; Moisture; Monitoring; Oil insulation; Power transformer insulation;
Conference_Titel :
Dielectric Liquids, 1999. (ICDL '99) Proceedings of the 1999 IEEE 13th International Conference on
Conference_Location :
Nara
Print_ISBN :
0-7803-4759-5
DOI :
10.1109/ICDL.1999.798890
