Effect of Electric Field Distribution on Branching Characteristics of Streamers in Transformer Oil

Electrical insulation and discharge phenomena under high electric fields pose critical limitations on the overall performance and reliability of oil‐immersed transformers. Under high electric fields, transformer oil is prone to streamer discharge, and the changes in electric field distribution caused by streamer branching directly influence the streamer development process and breakdown voltage of the oil. However, due to limitations in observation equipment and recording systems, the electric field distribution changes induced by streamer branching during discharge are challenging to measure directly. To address this, a two‐dimensional needle‐plate discharge model in transformer oil was established. Based on experimentally obtained streamer discharge images, a discharge fractal model was constructed frame by frame, and the fractal dimension was calculated using the box‐counting method to validate the model's accuracy. Subsequently, the influence of electric field distribution on streamer branching development was analyzed through electrostatic field simulations, and a probability function describing the relationship between electric field strength and branching development was obtained via statistical analysis. This study is significant for improving traditional simulation models, providing a more reasonable simulation of discharge fractal phenomena under actual conditions, and contributing to a deeper understanding of transformer oil discharge mechanisms.