Lagrangian Model of an Isolated DC-DC Converter With a 3-Phase Medium Frequency Transformer Accounting Magnetic Cross Saturation

This article presents a nonlinear equivalent circuit model of an isolated dc-dc converter with 3-phase medium frequency transformer. The takes into account the magnetic cross saturation core-type circuit. is suitable in detailed electromagnetic transient simulations power systems involving converters. developed using Lagrange energy method. It involves matrix dynamic inductances containing term resulting from core magnetization and linear leakage flux. parameters are determined based on series magnetostatic finite element method simulations. approach convenient when applied to high transformers offering limited characterization effort, or if transformer prototype does not exist. experimental validation performed novel MFT 100 kW 1.2 kV 20 kHz dual active bridge has proved validity parameters. no-load steady-state inrush tests full-load test show very good fit between simulated experimentally measured waveforms. comparison classical simplified neglecting shows significant difference test.