Title :
Electric field in transformer oil measured with the Kerr-effect technique
Author :
Nonaka, Y. ; Sato, H. ; Maeno, T. ; Takada, T.
Author_Institution :
Dept. of Electr. & Electron. Eng., Musashi Inst. of Technol., Tokyo, Japan
fDate :
4/1/1991 12:00:00 AM
Abstract :
The electric field distribution in transformer insulating oil was measured as a function of time, both after application of a DC step voltage and after polarity change of the DC voltage, using a highly sensitive advanced Kerr electro-optic technique. The lower limit of the applied electric field intensity was 100 V/cm in insulating oil with an electrode length of 8 cm. Charge distribution as a function of time was calculated from the measured electric field distribution. The mobility of ionic carriers, 2.1×10-5 cm2/Vs, in paraffinic transformer oil was obtained from the relationship between the saturation time of charge density and the applied DC voltage. The relaxation time of accumulated charge near the electrodes after short-circuiting the electrodes was independent of the pre-applied DC voltage
Keywords :
Kerr electro-optical effect; electric field measurement; insulating oils; transformer insulation; DC step voltage; Kerr-effect technique; accumulated charge; applied electric field intensity; electric field distribution; electro-optic technique; electrode length; insulating oil; paraffinic transformer oil; polarity change; relaxation time; saturation time; transformer oil; Charge measurement; Circuit faults; Current measurement; Dielectrics and electrical insulation; Electric variables measurement; Electrodes; Oil insulation; Petroleum; Power transformer insulation; Time measurement;
Journal_Title :
Electrical Insulation, IEEE Transactions on
