THE INFLUENCE OF PARTIAL DISCHARGES ON THE DIELECTRIC PROPERTIES OF OILS USED IN POWER TRANSFORMER
DOI:
https://doi.org/10.36801/Keywords:
partial electric discharge, transformer oils, dielectric propertiesAbstract
Degradation of the insulation systems is the main cause of failure of electrical power transformers (PT). A very harmful factor that contributes to the degradation of the power transformer insulation systems (PTIS) are the partial electrical discharges (PD). Therefore, the monitoring of the PD level in the power transformers is very important, as this can prevent very serious faults of the PTIS. The paper presents an experimental study regarding the variation of the main dielectric properties of the oils used in PTIS as a result of partial electric discharges. Experimental results obtained on samples of mineral oil and transformer vegetable oil are presented. These indicate that, under the action of the electric discharges, the main dielectric properties of the investigated oils are getting worse. These results well agree with those presented in previous paper. However, compared to other published studies, the presents results are obtained on aging cells equipped with a point-cylinder electrode system in such a way the electric discharges occur inside the oil samples.
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