Fractal Analysis of Creeping Discharges Propagating over Solid/Liquid interfaces-Influence of Oil Level

This paper investigates the use of solid/liquid insulating structures with different oil levels to minimize the effect of damages occurred due to creeping discharge activity. A test setup based on a point-plane electrode system, connected to a high voltage AC transformer is used to analyze the propagation of creeping discharges using optical observation. A three-dimensional model is used to simulate the effect of electric field distribution on the interface over creeping discharges upon different oil levels. The results show that the number of branches, light emitted and fractal dimension given by the box-counting method decrease with the increasing oil level.