Existing icing experiments of transmission conductor are not carried out under operational condition

so the results can not simulate the real icing characteristics of transmission lines. Consequently

by isolation and insulation improvements of high-voltage and large-current generators

developed the experimental equipment for icing accretion which can output the highest voltage of 400 kV and the maximum current of 1 500 A simultaneously. Icing accretion experiments for transmission conductor with the type of LGJ-460/60 and LGJ-630/55 were carried out with simultaneous voltage and current under natural environment. Icing thickness and density variation curves with operating voltage and current were obtained. Based on the above works

a novel energized icing accretion model of conductor was proposed.Experimental results show that the increase of icing thickness can be restrained through decreasing freezing speed of water droplets on conductor by Joule heat arising from running current. When the electric field around the test conductor is low

the water droplets move faster after being polarized and energized

then icing thickness grows gradually with the increase of operating voltage. When the electric field is increased to the appearance of corona and ion beam around the test samples

the growth of icing thickness can be slowed by Joule heat arising from corona current and collision between ions and water molecules. And burr-like ice treeing will appear on the ice surface because of influences of electric field

also

the density of ice layer decreases with the increase of conductor voltage. Results of this research are available for guidance to the anti-icing design and transformation of operating transmission lines in heavy icing areas.