A New Numerical Scheme for the Simulation of Corona Fields

A new numerical scheme is proposed for the computation of the corona space charge density and electric field distributions in wire-duct electrode configurations. An electric vector potential formulation is used for the computation of the electrostatic field, whereas the current continuity equation is applied for the derivation of the space charge density. We apply a technique based on a combination of finite element and donor cell methods. The solution procedure is obtained iteratively by using the Newton-Raphson algorithm in order to converge to a self-consistent solution. The same mesh is used throughout the whole iterative procedure. The Kaptzov´s condition is easy to handle and there is no need for an outer loop in order to impose the correct charge condition on the surface of the corona wire electrode. Numerical results are presented.