Computation of ground current density profiles of unipolar DC corona

A novel approach for computing ground-level current density profiles of unipolar DC corona is described. An analysis is performed to study the influence of Deutsch´s assumption (i.e. that the space charge affects only the magnitude and not the direction of the electric field) on the ground-level current density distributions. The distortion of the ion trajectories caused by the corona-generated space charge is established using a referenced formula for the saturation case. A parameter that characterizes the degree of distortion and its dependence on the corona intensity is introduced in the analysis. Modified analytical formulas are derived for the current density distributions at the ground level. Comparisons with experimental data show that the proposed expressions can be used with sufficient accuracy for assessment of right-of-way profiles