Streamer Generation and Propagation in Dibenzyltoluene and Ester liquids under High Temperature

The characterization of pre-breakdown streamers in liquids is carried out under high temperature up to 200°C. Measurements are obtained either in a high temperature non-polar liquid (dibenzyltoluene, DBT), or in a synthetic ester (Midel®7131) for comparison. Streamer inception voltages are measured in both polarities, as well as propagation velocities. The results obtained show that only minor modifications are recorded when temperature is raised up to 200°C. Due to its stability at high temperature, DBT constitutes an interesting solution in the perspective of using liquids for the insulation of high temperature power electronics.