High Efficiency FEM Calculation of the Ionized Field Under HVDC Transmission Lines

As many high voltage direct current (HVDC) projects are constructed in China, the ionized field problem is of wide concern. The upstream finite element method (Upstream FEM) has good adaptability and is widely used to analyze the ionized field under HVDC lines. Galerkin's scheme is used to improve the charge density precision. Poisson's equation solution technique and charge density updating strategy are adopted to accelerate the calculation. The charge density precision and the calculation efficiency is remarkably improved. For the 15 000-nodes-scale ionized field problem of bipolar-6-bundled HVDC lines, the calculation time is less than 5 s. The algorithm also shows good robustness to the charge density initial value in the numerical cases.