The Streamer Discharge Simulation of Transformer Oil-based Nanofluids

Abstract

Transformer oil plays an important role in the insulation of power equipment such as power transformers and bushings. Due to its good thermal conductivity and insulating properties, the transformer oil-based nanofluids (TNFs) have been received more and more attention as a new kind of liquid dielectric. In order to explore the modification mechanism of TNFs, a two-dimensional axisymmetric fluid dynamics model is established to simulate the streamer discharge behavior in it. In this model, the positive steamer discharge behavior in pure transformer oil and TNFs is studied with different electrode distances and addition of different kinds of nanoparticles in a needle-plate electrode. Modeling results indicate that by adding nanoparticles to the transformer oil, the development of streamer discharge is significantly slower, and the density of negative charges in the streamer channel apparently increases. When different kinds of nanoparticles are added, nanoparticles with a larger saturation charge can result in a slower streamer rate. It can be seen that the addition of nanoparticles effectively inhibits the development of the streamer discharge process. Because of the electric field, the negative electrons attach to nanoparticles in a short time and generate negative nanoparticles. In addition, the inhibition of the development of streamer is more pronounced by the nanoparticles with larger saturation charge, adsorbing more electrons in the same period of time. Therefore, the development of the streamer is slowed down and the insulation properties of the transformer oil are improved.