Simulation Study on the Morphology of Streamer Propagation in Insulating Oil

A thermal electric model for the initiation and transmission of streamer leading to electrical breakdown has been proposed. We have constructed a migration rate jump mechanism for positive ions, negative ions, and electrons, expanding the macroscopic size of the streamer in insulating oil. The analysis using COMSOL Multiphysics shows that compared to the original model, the shape of the streamer has been greatly expanded, which can better reflect the actual shape of the streamer. In addition, the dynamic development process of the streamer indicates that the initial shape of the streamer does not exhibit branching structures, and only when the electric field threshold is reached, the streamer will exhibit more obvious branching structures. We confirmed the effectiveness of the model in predicting the streamer morphology under different voltages by simulating the streamer morphology under different voltages.