Two-dimensional simulation on the glow to streamer transition from horizontal conductors

It has been recently suggested that glow corona generated during thunderstorms could have an important role in the initiation of streamers and upward connecting leaders from power transmission lines. In order to further investigate this, a two-dimensional evaluation of the glow corona generation is here reported, which takes into account the non-equilibrium ionization layer around the conductors. The critical change rate of the background electric field required for the transition from glow corona to streamer initiation is obtained. A numerical strategy to evaluate the glow corona to streamers transition for large gaps and irregular geometries is proposed and validated. A four-bundled conductor is also studied and results showed that when evaluating the critical rate of rise of the background electric field for a bundle conductor during thunderstorms, it could be viewed as a single conductor with the equivalent geometric mean radius of the wire configuration. Last, a study case is performed to estimate the effect of the glow corona on the streamer inception from UHV transmission lines during thunderstorms.