AC breakdown strength performance of plasma treated mineral oil-based nanofluids

Nanofluids have been identified to be one of the suitable approaches to increase the breakdown strength of transformer oil. However, the nanofluids tend to form sediment which nullifies its full capabilities in increasing the electrical properties such as higher AC breakdown strength. In view of foregoing, this paper presents an approach to enhance the AC breakdown strength of the transformer oil by using plasma treated silica nanoparticles to form plasma treated nanofluids. The surface of silica nanoparticle was functionalized by using atmospheric pressure plasma discharge to enhance the interfacial interaction in order to improve the sedimentation issue in nanofluids. Plasma treated nanoparticles with desired surface functionality can strongly interact with liquid molecules with better dispersed into the base fluid to form a stable suspension. The AC breakdown strength of oil samples before and after surface modification of nanoparticles were measured accordance to IEC 60156 standard. Based on obtained results, it was found that the plasma treated nanofluids had higher AC breakdown voltage compared to the pure oil and the untreated nanofluids.