Impact of icing severity on corona performance of glaze ice-covered conductor

This paper presents the results of laboratory experiments carried out on an ac-energized stranded conductor subjected to simulated glaze icing, which were conducted in a corona cage located in an artificial climate chamber. With the increase of icing duration, the grow of icing severity of conductors lead to the corona onset voltage fell from 54.8 to 41.9 kV, correspondingly, the surface irregularity of stranded conductor decreased from 0.41 to 0.31. Through the ultraviolet photon frame and ultraviolet photon curve, corona development process of glaze ice-covered conductor were divided into three stages, that is, burst corona mode, comprehensive corona mode and glow mode. The impact of icing severity on the corona loss and audible noise was investigated. With regard to corona loss, it is in proportion to icing severity at a given surface gradient, whereas no obvious impact was observed with audible noise could be established. In addition, corona performance in comparison with rain condition was also studied, the corona loss of glaze ice-covered conductor was higher than that of rain, instead the audible noise of glaze ice-covered conductor was lower than that of rain after a certain surface gradient. The presented results could provide references to the design of ac overhead transmission lines crossing cold regions.