Transient Behavior in Transformer Oils: Prebreakdown and Breakdown Phenomena

A quantitative correlation between streamer velocities and impulse breakdown voltages has been established for point-plane geometries. We have extended these studies to less divergent fields (rod-plane) where we have identified two regions for impulse breakdown in liquids, oneiationinitiation-Inintrolled and a second controlled by streamer propagation rate. Which controls breakdown is determined by electrode geometry (field divergence), liquid composition, and wave shape. The influence of these parameters has been determined and a general model for the prediction of impulse breakdown voltage is proposed.