Lightning Field Distribution Analysis in Railway Catenary Systems Using Finite Difference Method

The study analyzes electric field distribution around railway catenary systems and assesses lightning strike risk to inform railway lightning protection. The spatial electric field near the catenary is calculated, and the influence of the initial lightning downward leader stage on this field is examined. A fractal propagation model simulates the lightning attachment process. Results show the downward leader head significantly alters electric field intensity and distribution: movement from zone A to C increases surface field intensity by 52 kV/m (feed wire), 44 kV/m (catenary), and 22 kV/m (carrier cable). Proximity of the lightning leader's start position to the catenary causes pronounced field distortion, particularly around the feed conductor. During final jump conditions, the lightning channel distorts the atmospheric electric field, especially near the leader head. When developing above the catenary, the downward leader head exhibits zone‐dependent propagation probabilities. Field distortion around feed wires and catenary in zones B and C attracts downward leaders toward these zones. Consequently, the feed wire experiences higher lightning strike risk than other conductors. Analysis indicates the feed wire also provides shielding protection for adjacent wires.