Laboratory investigation of AC corona loss and corona onset voltage on a conductor under icing conditions

Corona losses generated from energized conductors, especially in foul weather conditions, is one of the most important economic factors influencing the design of extra-high voltage (EHV) and ultra-high voltage (UHV) transmission lines. In the present paper, results of laboratory experiments under icing conditions are presented. Two types of ice are considered: rime and glaze. The conditions of ice formation on the test conductor are presented. During the ice accretion, an electric field was applied to the conductor to investigate corona loss and corona onset voltage. The presence of glaze results in a higher corona loss and a lower corona onset voltage compared with rime. The influence of wind velocity and freezing water conductivity were also studied. The test results can help to estimate corona losses of transmission lines in cold climate regions and to improve the design of transmission lines.