Influence of glaze-iced insulators on force and motion characteristics of charged water droplets under DC voltage and natural icing test validation

Glaze ice exhibits high density and strong adhesion, readily forming ice bridges that impair insulator performance. While previous studies have primarily concentrated on macroscopic icing behavior under AC or DC fields, the role of icicles in affecting the motion of charged water droplets has received little attention. To fill this gap, the LXY-160 glass insulator is selected as the research object. Glaze icing and flashover tests are first conducted under natural outdoor conditions. A DC-voltage-based multi-physics coupling model is then developed to simulate charged droplet trajectories and analyze their force characteristics and trajectory deviation characteristics. The simulation results are validated against experimental data. The findings indicate that locally high-field-strength regions form at the icicle tips, significantly enhancing the electric field force on charged water droplets. An increase in either droplet diameter or applied voltage intensifies this force, whereas a higher wind speed shortens the residence time of droplets in the high-field-strength region, thereby weakening the electric field effect. Under a positive DC voltage, the trajectory displacement difference of negatively charged droplets is larger than that of positively charged droplets. This displacement difference increases with droplet diameter and applied voltage, but decreases with icicle length and wind speed. Experimental data indicate that applying voltage leads to greater ice mass than under non-energized conditions. Raising the voltage bends icicles, increases internal bubble count, lowers ice density, and roughens the ice surface. Moreover, as the applied voltage rises, the flashover voltage first declines and then increases.