Indian Journal of Science and Technology

Abstract

Objectives: To review the electrical property of different nanofluids such as AC/DC and impulse breakdown strength, partial discharge inception characteristic, dielectric loss factor and electrical resistivity. Methods: Dispersion of nanoparticles to host fluid is carried out by single-step and two-step methods to enhance the basic properties of nanofluids such as electrical and thermal conductivity, dielectric constant, denseness and relaxation time constant. Single step method follows the dispersion of nano particles into host fluid directly. In two-step method, dry powders of nano particles are prepared in first stage, which is dispersed to host fluid through magnetic stirrer or ultrasonic methods in second stage. Findings: The nanofluid in transformers can enhance the dielectric strength by almost 15-20% compared to mineral oil. The performance of the nanofluids under heavy electrical stress depends upon the types, volume fraction, shape and size of the nanoparticles dispersed in host fluid. The investigations conducted over the mixture of nanoparticles and transformer oil concludes that the electrical performance of the carrier oil is highly influenced by dispersing the nanoparticles of different varieties, mass and shape. The dispersion of nanoparticles will change the mode of ionization, reduces the formation of the electrons responsible for the breakdown, and thus delay the breakdown time. Applications: The excellent heat transfer and electrical isolation characteristics are the prerequisite of insulating liquids used in power transformers. Because of superior electrical and cooling performance of nanofluid compared to mineral oil at high voltage levels, the dielectric world has recognized the nanofluid as a promising insulating substitute for transformers.

Keywords: Electrical Characteristics, Dielectric Strength, Nanofluid, Review, Transformer Oil, PDIV