The electric field distribution in oil-cardboard composited insulation system under a Polarity reversed voltage

Taken a composited insulation system of oil and cardboard filled in two parallel tabulate electrodes as research object, the electric field distribution in the composited insulation system, which is stressed by a polarity reversed voltage, has been studied. This is carried out by means of establish and solve a differential equation describing the field distribution. The main factors influencing the field distribution characteristics have also been studied. The research result shows that: Because of the polarized electric charges located on the interface of oil and cardboard, there is a long time electric field redistribution transition process in the oil and cardboard when a polarity reversed voltage acted across the composited insulation system, and an obviously increased electric field intensity may appears in oil during this transition process.