INFLUENCE OF MECHANICAL IMPURITIES ON DIELECTRIC STRENGTH OF TRANSFORMER OIL
The influence of mechanical impurities on dielectric strength of HC transformer oil has been studied. The breakdown voltage of HC oil and its model mixtures containing different concentrations of fine copper, steel, and cellulose fibers were measured. The tests using model mixtures with addition of water were carried out for comparison purposes. It was found that the model mixtures containing cellulose fibers showed the worst values of the breakdown voltage and dielectric strength, respectively. The dielectric strength decreased by 3,7 times, while in the presence of water, the dielectric strength decreased by 1,77 times.