AC Breakdown Voltage Thermal Dependence in Magnetic Fluids

This study examines the AC breakdown voltage of novel transformer oil, produced using gas-to-liquid (GTL) technology, and two nanofluids prepared using this oil. The first nanofluid is a mono-nanofluid consisting of fullerene C
60
nanoparticles at a concentration of 0.01 %w/V, while the other is a hybrid nanofluid called C
60
-loaded ferrofluid, which contains both fullerene C
60
nanoparticles (0.01 %w/V) and iron oxide nanoparticles (0.01 %w/V). The AC breakdown voltage (BDV) of both nanofluids and the transformer oil was experimentally investigated at temperatures ranging from 30°C to 60°C. This experimental study reveals that the dielectric strength of pure GTL oil decreases with rising temperature by around 7 % when the lowest and the highest temperature values of AC BDV are compared. However, both nanofluids showed an increment in AC BDV value at higher temperatures and the differences in comparison to AC BDV at temperature 30°C were 5.7 % and 4.7 % for nanofluid with C
60
nanoparticles and nanofluid with both kinds of nanoparticles, respectively. Enhancement of AC BDV value of nanofluids in comparison to pure oil increased with temperature and the maximal improvements reached values over 12 % for C
60
nanofluids and up to 34 % for C
60
-loaded ferrofluid at the temperature 60°C.