Irregular-shaped Particle Motion and Charge Transfer Mechanism in Transformer Oil under Varying Field

Abstract

The presence of particle in transformer oil can cause significant problem to insulation system of transformer which can lead to a partial discharge inception and further extend to a complete breakdown. Many studies primarily considered the spherical particle for the investigation to understand the effect of particle in oil. Contribution towards understanding the effect of irregular-shaped particle in oil are very limited. This paper introduces a modified general equation for irregular-shaped particle motion in transformer oil. Additionally, the charge transfer and discharge mechanism of particle under uniform and non-uniform field is also investigated. The newly modified equation is more general in nature and can be used for any shape of particle motion in oil whereas the existing equation mainly explained for spherical particle. The electrostatic Coulomb force experienced on the irregular-shaped particle explicitly discussed in the presented work. The modified equation also includes the electric field gradient force component and thus can be considered valid for any particle in transformer oil under different type of field configurations.