Droplet Distributions and Electric Fields on the Angled Railway Composite Insulator

Composite insulators in railway systems are often installed at inclined angles, supported by cantilevers positioned relative to the railway masts and overhead line configurations. These inclinations significantly influence droplet deposition patterns, self-cleaning performance, and the distortion of electric field distribution. Such distortions can alter the mechanical and electrical properties of the insulators, potentially impacting electrical resistance, discharge activity, and the risk of flashover. This study investigates the electric field distribution of 25 kV composite railway insulators under clean and wet conditions. Experiments included artificial rain sprayed onto insulators at various orientations, captured via imaging, alongside simulations using Finite Element Analysis software. Results revealed that insulator orientation affects water droplet distribution and self-cleaning performance. Horizontal insulators exhibited superior self-cleaning efficiency, with droplets moving downward due to gravity and angle. Inclined insulators displayed acute and obtuse contact angles, with skewed ellipsoid droplets creating non-uniform electric fields and intensities concentrated at droplet edges. In contrast, horizontal insulators maintained more symmetric field distributions. Despite these differences, the maximum electric field intensities occurred near end fittings and remained below the critical value for corona initiation. These findings highlight the importance of insulator orientation in optimizing performance and mitigating risks associated with wet conditions.