Analysis of the Image Characteristics of Streamer Discharge in the Rod-plate Gap under Positive Lightning Impulse

The quantitative features analysis of discharge image information in long air gaps can be regarded as new physical observation parameters for discharge research and be of great significance for understanding the mechanism of lightning impulse discharge. Stream discharge is the initial stage of air gap discharge, and its formation and development have a significant impact on the subsequent leader discharge process. For the deeply exploration of the image features in streamer discharge, based on the observation of the 1 m rod-plate gap discharge under the lightning impulse discharge at high altitude, EMICCD (Electron Multiplier Intensified Charge Coupled Device) discharge images with nanosecond exposure time and time interval, synchronous discharge voltage, and current were obtained through repeated discharge tests under the positive lightning impulse with the same voltage level. By analyzing the intensity characteristics of discharge light intensity images at different discharge times, the intrinsic relationship between discharge light intensity images and discharge current was discussed. The result was shown that there is a good linear relationship between the average intensity integral of streamer discharge in the rod-plate axis and its discharge current.