Calculation of DC Bias Reactive Power Loss of Converter Transformer via Finite Element Analysis

This paper proposes a novel and applicable approach to calculate the reactive power loss of converter transformer under dc bias. By using this proposed method, only general information of the converter transformer and the network is needed for the calculation within a certain dc current range. Specifically, a three-dimensional model of +/- 800 kV converter transformer model for simulation test is established by the finite element method. Through simulation test, the electromagnetic characteristics and reactive loss characteristics of converter transformer under dc bias can be obtained, and the relationship between the bias current and the reactive loss of +/- 800 kV converter transformer is quantified. Simulation results validate the feasibility of proposed algorithm.