AC and lightning breakdown strength of transformer oil modified by semiconducting nanoparticles

In this paper, semiconducting nanoparticles were used to modify the transformer oil by means of sonication. AC and lightning breakdown voltages of the transformer oil samples were measured before and after modifying according to IEC standards. Test results of every oil sample based on 30 breakdowns were used to model the probability distribution of breakdown voltage by Weibull statistical method. It was found that the mean AC breakdown voltage of nanofluid with optimum concentration was 1.26 times of that for the base oil. The withstand voltage of semiconducting nanofluids at 1% probability breakdown rises to 1.58 times than that of mineral oil. Meanwhile, the mean lightning breakdown voltage of nanofluid was increased by 24% than that of the transformer oil, respectively.