Experimental Investigation of the Effect of Different Temperatures on Pressboard Impregnated with Transformer Oil-Based Nanofluids

The purpose of this article is to study the effect of different temperatures on the clearing of dry pressboard insulation and compare the effects of different temperatures on the process of impregnating pressboard with transformer oil mixed with nanoparticles. In this research, a conducting magnetite ($Fe_{3}O_{4}$) nanoparticle with a size not exceeding 50 nm is selected, and the concentration of nanoparticles used in this research is 0.01% of the volume of transformer oil. In addition, Span 80 surfactants or emulsifiers have been selected to improve the compatibility of transformer oil mixed with nanoparticles. In this research article, the electrical properties of pressboard insulators are tested with an AC voltage and the lightning impulse voltage test on both the positive and negative poles according to international standards. The test results showed that by drying pressboard insulation at 105°C and then impregnating pressboard insulation in transformer oil mixed with nanoparticles at 80°C, the pressboard insulation was dielectrically strong for AC voltage and had the best lightning impulse voltage.