Title :
Investigation on transformer oil impedance during breakdown under AC voltage
Author :
Abdi, S. ; Boubakeur, A. ; Harid, N. ; Haddad, A.
Author_Institution :
Univ. of Medea, Medea, Algeria
Abstract :
In this paper, we present an experimental study on the properties of mineral oils under AC breakdown conditions. Breakdown tests were carried out on mineral oil samples using a sphere-sphere electrode test cell for various gap lengths 1 mm, 2.5 mm and 5 mm and at different voltage speed ramps: 0.5 kV/s, 2 kV/s and 3.5 kV/s. The dynamic impedance of the mineral oil samples was determined from the instantaneous ratio of voltage and current. Such dynamic impedance can be used to explore the properties of the arc and its development within the oil. The results of this investigation show that the gap length and the voltage speed ramp have a significant influence on both the impedance magnitude and the decay time taken to reach the minimum impedance.
Keywords :
arcs (electric); transformer oil; AC breakdown conditions; AC voltage; arc property; breakdown tests; current instantaneous ratio; distance 1 mm; distance 2.5 mm; distance 5 mm; dynamic impedance; mineral oils; sphere-sphere electrode test cell; transformer oil impedance; voltage instantaneous ratio; voltage speed ramp; Breakdown voltage; Dielectric breakdown; Dielectric liquids; Electrodes; Impedance; Minerals; Oil insulation; Petroleum; Power transformer insulation; Testing;
Conference_Titel :
Electrical Insulation and Dielectric Phenomena, 2009. CEIDP '09. IEEE Conference on
Conference_Location :
Virginia Beach, VA
Print_ISBN :
978-1-4244-4557-8
Electronic_ISBN :
0084-9162
DOI :
10.1109/CEIDP.2009.5377871
