AC corona pulses amplitude and frequency related to pressure and humidity

Compared with DC corona, the physical process of AC corona is more complicated. Through the rod plane electrodes, AC corona characteristics varied with air pressure and humidity were researched in the chamber made of Perspex. The relationships between average amplitude of AC corona pulse and air pressure or humidity, between the frequency of AC corona pulse and air pressure or humidity were studied. The average amplitude of AC corona pulse was inversely proportional to humidity. The amplitude decreased in positive half-cycle and increased in negative half-cycle with the fall of air pressure. What´s more, the repetition frequency of AC corona pulses increased with the rise of the humidity. The frequency had little change with the fall of air pressure in the positive half-cycle, while rising in negative half-cycle obviously.