The presence of free conductive particles may reduce the dielectric strength of gas-insulated transmission lines（GIL）. Studying the motion of particles after collision with electrodes or insulators can guide the settings of traps

and the recovery coefficient is an important variable for simulating the motion of particles accurately. Therefore

a platform of measuring recovery coefficient was established to study the variation of recovery coefficients hn and ht with size

material and angle of particles. Based on the experimental results

the motion of the particles with different sizes near the convex and concave surfaces of the basin insulator was simulated. The results showed that particles near the convex surface experienced horizontal scroll

lifting-off

climbing along the insulator surface and rebound. According to the difference sizes of particles

the climbing along the surface of the insulator was divided into two kinds states: the steel particles less than 0.62 mm climbed to the high voltage electrode along the surface of the insulator and then entered the rebound state; the steel particles greater than 0.62 mm moved to a certain position along the surface of the insulator and then vibrated decreasingly and finally adhered to the surface of the insulator. However

the particles move away from the insulator in the manner of bounce due to collision or horizontal movement near the concave surface.