Investigation on breakdown strength of mineral oil based carbon nanotube

Interests on nanomaterials for enhancing the insulation properties of dielectric liquid are growing in recent years. This paper presents experimental studies dealing with the influence of carbon nanotube (CNT) nanomaterials in AC breakdown voltages. The observations of AC electrical breakdown voltages of CNT disperse in mineral oil at 2.5mm gap distance were recorded. Five different amounts of concentrations of CNT in mineral oil are within the range from 0.01 to 0.20g/L. By analyzing the AC breakdown voltage using normal distribution, the probability of breakdown failure can be estimated for designing insulation in transformer. In order to test the validity of normal distribution, Shapiro-Wilk technique was used in this experiment. Based on the investigations, it is shown that 0.01g/L and 0.05g/L CNT nanofluids were possible to enhance dielectric strength of mineral oil. These three concentrations are considered to have a greater potential to be as alternative transformer oil. However, as for 0.10g/L and 0.20g/L CNT nanofluids, AC breakdown voltages show the opposite outcome.