Highly Stable Upwind FEM for Solving Ionized Field of HVDC Transmission Line

The ionized field produced by corona discharge from a high-voltage direct current (HVDC) transmission line has a great influence on the electromagnetic environment. In this paper, a highly stable iterative algorithm based on an upwind finite-element method is introduced to analyze the ionized field of HVDC transmission line in the presence of the wind. The Kaptzov´s assumption is introduced on the conductor surface as a boundary condition. In the iterative procedure presented by Takuma, the controlling method is added to guarantee the convergence of the iteration, which has been tested to be effective. The impact of the wind on the ground-level electric-field intensity and ion current density of a bipolar HVDC transmission line is analyzed, and we find the wind has a significant influence on the ionized field which has to be considered in the engineering design.