Analysis of current density and electric field beneath a bipolar DC wires-to-plane corona discharge in humid air

This paper aims to analyze the behavior of DC bipolar corona discharge in a two wires-to-plane configuration under variable humid air conditions. A circular biased probe was adapted to the plane and used to measure the ground-plane current density and electric field during the bipolar corona. The values of the electric field and the current density at the plane surface were the maximum beneath the two corona wires which decreased when moving away from them. The current-voltage characteristics followed the quadratic Townsend's law. The experimental results show that the bipolar corona discharge is strongly affected by the air humidity. The current density and the electric field decrease linearly with the humidity for all the tested wire diameters.