Characteristics of Streamer Discharge Along the Insulation Surface With Embedded Electrode

Surface discharge is a common accident in power systems, significantly impacting the safe and stable operation of the power grid. The insulation structure of power equipment is intricate, and surface discharge characteristics are influenced not only by the insulation material but also by electrode geometry. In the article, characteristics of streamer discharge along the insulation surface with embedded electrodes are investigated under negative dc voltage. The streamer propagation field, velocity, and luminous intensity are measured by photomultiplier tubes and an ICCD camera. Unexpectedly, the disparity in the characteristics of streamer discharge along the insulation surface, with and without an embedded electrode, is substantial. Furthermore, the investigation also reveals that the length of the embedded electrode has a significant influence on the characteristics of surface streamer discharge. Through analysis, it has been determined that the presence of the embedded electrode does not significantly impact the electric field along the insulation surface. However, it has an influence on the charge distribution on the insulation surface, consequently affecting the characteristics of surface steamer discharge. The findings from this research will provide valuable technical support for enhancing external insulation design and operation strategies in dc bushings and other related equipment.