The impact of negative dc corona discharge on the ultraviolet photon count in rod to plane air gaps

The observation of corona discharge points on the surfaces of the insulating materials and conductors seem to be quite crucial during the corona researches. The ‘solar blind’ ultraviolet imaging detector cameras have performed efficiently in detecting corona discharge in power facilities. In order to investigate the negative dc corona effects on ultraviolet photon count, a corona measurement system based on rod to plane air gaps was established. The corona current, Trichel pulses and corona- generated photons were measured with the raise of applied voltage. An approximate parabolic function was found to exist between the photon count and the corona current. And also an ideal quadratic function was discovered to exist between the photon count and the frequency of Trichel pulses. These results have provided solid foundation in the application of UV imaging detection of negative dc corona in power equipments.