Investigating the Magnetic Field Dominated Streamer Dynamics in Transformer Oil

Abstract

Transformer oil is a crucial insulating medium in power transformers, and understanding its behavior under various conditions is decisive for ensuring the reliability and efficiency of power distribution systems. Transformers, as electromagnetic devices, are continually exposed to both electrical and magnetic forces. Due to large electrical stresses, the dielectric characteristics of the existing dielectric fluid degrade, causing an arc to begin and propagate. A Lorentz force, which combines electrical and magnetic forces, affects both the speed and rotations of energized atoms and the electrical discharge trajectory. This study investigates the implications of a magnetic field on streamer propagation within transformer oil, a phenomenon that plays a crucial role in the breakdown of insulation. This study employs COMSOL Multiphysics software to explore the implications of a magnetic field on streamer dynamics in transformer oil. In a simulation study, an impulse voltage is applied to initiate the streamer within the oil for the analysis of their propagation characteristics under the simulated magnetic field. The results revealed a substantial impact of the magnetic field on the initiation, direction, velocity, and morphology of streamers within the oil. These observations suggest that the magnetic field plays a crucial role in shaping the breakdown behavior of insulation.