103 / 2017-03-26 15:43:44

Analysis of DC Characteristics of Three Phase Transformer Based on Load Classification

高电压与绝缘技术

Abstract—The DC component of the transformer can cause the neutral point potential shift and the DC bias of the transformer, which can cause the vibration and noise of the transformer, and endanger the effective operation of the power grid. To solve the DC bias factors and influence on three-phase transformer DC source of in-depth research, simulate and study the effect of DC component in three-phase transformer from the the view of load, and provide theoretical support for the research on the problem of DC suppression measures. Nonlinear load, three-phase unbalanced load and impact load of three-phase transformer based on Simulink toolbox of 3 equivalent simulation models were built,The results show that the design of simplified simulation system can meet the requirements of DC characteristics of three-phase transformers.The simulation results show that the increase of the nonlinear load power can cause the DC component of the magnetizing current to increase correspondingly, the power of the secondary side of the power surge caused a rapid increase in the harmonic content of the three-phase voltage and current, and generate negative sequence component, and caused three phase asymmetric operation.
Keywords—DC characteristics; Simulation; Negative sequence component; Three-phase asymmetry