Experimental Study of the Electrical Strength of Transformer Oil Containing Conductive Graphite Particles
Year: 2026
Type: conference-paper
Abstract: This paper investigates the mechanism of dielectric strength reduction in transformer oil under the influence of an alternating current voltage in the presence of conductive impurities. The reliability of high-voltage equipment critically depends on the quality of the liquid insulation, the degradation of which is often associated with the accumulation of particles and the formation of conductive bridges. To evaluate the influence of an alternating electric field, experiments were conducted with transformer oil-based nanofluids containing varying concentrations of conductive graphite nanoparticles. Dielectric strength measurements demonstrated its consistent decrease with an increasing dispersed phase concentration. Using optical photocolorimetry, it has been experimentally proven that the alternating electric field significantly intensifies the particle agglomeration process, as the proportion of sedimented nanoparticles increased from 15% to 24% upon voltage application. The physical mechanism of liquid breakdown under these conditions is substantiated: under the action of an AC field, graphite particles polarize and align into conductive chains due to dipole-dipole attraction. These structures act as microscopic asperities, causing a significant local distortion of the electric field. This initiates the generation of streamers and leads to the breakdown of the interelectrode gap at voltages substantially lower than the breakdown voltage of pure oil.
Institution: Novosibirsk State Technical University
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W7202249727