STATISTICAL STUDY OF THE OIL DIELECTRIC STRENGTH IN POWER DISTRIBUTION TRANSFORMERS

Stefanos I. Spartalis - Michael G. Danikas - Georgia P. Andreou - George Vekris

   A number of distribution transformers have been studied regarding their dielectric strength and their previous stressing. The study has been carried out with the aid of statistical analysis. It seems that the distribution of oil breakdown voltage values follows the normal distribution. This is in agreement with previous published data, although it should be pointed out that the nature of distribution (normal or extreme) depends also on the breakdown mechanism in each particular case and/or on the particular conditions under which a fault has occurred.

Keywords: transformer oil, breakdown voltage, dielectric strength, normal distribution

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