The characteristics of negative corona discharge and radio interference at different altitudes based on coaxial wire-cylinder gap

Abstract

Abstract The corona discharge from transmission lines in high-altitude areas is more severe than that in plain areas. The radio interferences caused thereby are key factors to be considered in the design of transmission lines. To study the influence of altitude on the negative corona characteristics, a movable small corona cage experimental platform was established: experiments were conducted at four altitudes in the range of 1120‒4320m, and the corona current pulse and radio interference level of 0.8-mm diameter fine copper wire under different negative voltages were collected. The experimental results show that the average amplitude, repetition frequency, and average current of corona current pulse increase with the increase of altitude. The dispersion of pulse amplitude increases with the increase of altitude, while the randomness of pulse interval decreases continuously. Taking the average current as an intermediate variable, the relationship of radio interference level with altitude is obtained. The research has certain guiding significance for understanding the corona discharge characteristics of ultra-high voltage lines.