Research on Reduction of Magnetic Flux Bias in High Frequency Isolated Interconnection Converter for AC/DC Hybrid Microgrid

Abstract

Abstract. An essential issue of the high-frequency isolated converter interconnecting the AC/DC hybrid microgrid is the magnetic flux bias, which will cause saturation of magnetic core if not controlled appropriately. In order to solve the problem, this paper analyzes the reasons of the flux bias and models the magnetizing current in the s-domain. Based on the analysis and the model, a strategy for magnetic flux bias reduction is proposed. The strategy compares the peak of the magnetizing current at each switching time and controls the average of the magnetizing current to zero by applying an additional voltage to the winding of the transformer at the DC side. The simulation base on PSIM platform is implemented and the results verify the validity of the proposed strategy.