Statistical Investigation of AC Dielectric Strength of Flaxseed Oil

Natural esters are increasingly gaining prominence as an alternative to mineral oils in the insulating oil industry due to environmental, fire safety and sustainability concerns. This study aims to investigate the AC breakdown voltage of flaxseed oil, whose electrical properties have not been studied in detail to the best of our knowledge, under different electrode gap and rate of rise conditions. In these breakdown voltage measurements, the electrode gap and the rate of rise are selected as 1.0 and 2.5 mm, and 0.5, 2 and 3 kV/s, respectively, according to international measurement standards. It is observed that the increase of the electrode gap and rate of rise parameters increases the AC breakdown voltage of flaxseed oil. These measurements are analyzed statistically and their conformity with normal distribution is tested. After accepting the conformity with normal distribution for all electrode gaps and rate of rises, withstand voltages are calculated at 1%, 10% and 50% breakdown voltage probabilities, which are used as safety limits in the design of power system equipment. The obtained results reveal that the tests are more important in short electrode gap and 0.5 kV/s rise of rate conditions in power system equipment applications using flaxseed oil.