Analytic approximation of fault current contributed by DC capacitors in VSC-HVDC pole-to-pole fault

摘要

Based on the travelling wave analysis and Laplace transformation, this paper proposes a new expression for the approximation of current contributed by dc capacitor in VSC-HVDC networks during the pole-to-pole fault. To improve the accuracy of the theoretical analysis, the distributed, frequency-dependent DC line parameters and the skin effect are all considered. Using PSCAD software, a ±200 kV VSC-HVDC transmission system model is constructed, and extensive simulations are performed. Through comparing the analytic approximation calculation with simulation results, the validity and feasibility of the proposed expression are confirmed.