Current analysis of DC negative corona discharge in a wire-cylinder configuration at high ambient temperatures

摘要

To study the characteristics of DC negative corona discharge in a wire-cylinder configuration at an ambient temperature range of 350-850 ℃, the IeV characteristics and the current composition are analyzed under different conditions. A simple method is proposed to determine the DC corona onset threshold voltage. At high ambient temperatures, in the DC negative corona discharge gap, some electrons are not attached to the electronegative gas molecules and move to the anode tube. Thus, these electrons form an electron current, which may account for most of the total discharging current. The ratio of the electron current to the total discharging current increases with increasing temperature. In a mixture of O_2 and N_2 and a mixture of CO_2 and N_2, the ratio of electron current increases with increasing N_2 content in the mixtures. The cathode material has little influence on the corona discharge characteristics at high ambient temperatures.