Characterization of Partial Discharge from Bubble Defects in Cast Epoxy Resin Insulating Materials

Taking the bubble defects inside the insulation of environmentally friendly cast epoxy electrical equipment as the research object, the insulation discharge model containing the bubble defects was produced, and the continuous partial discharge test under constant voltage was carried out by the conventional pulse current method, and the trend of the air gap discharge measurement signals over time was statistically analyzed, and the morphology of the bubble defects changed after the discharge was observed. The results show that after a long discharge time of 72 h, the surface of the bubble defects appeared to be concave and collapsed due to the chemical rheological properties of the prepared epoxy resin materials, and the deformation of the bubbles would have an effect on the discharge statistical parameters. The average discharge amplitude shows a tendency of decreasing and then rising and then fluctuating repeatedly, and the maximum discharge amplitude shows an overall tendency of gradually decreasing. We provide certain data support for the manufacture of environmentally friendly epoxy resin cast insulation equipment and bubble defect detection.