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

Słowa kluczowe

DC-DC POWER CONVERTERS, MEDIUM FREQUENCY TRANSFORMER, MODELING

Rok publikacji

Język publikacji

angielski

Tytuł czasopisma / wyd. zwartego / tytuł konferencji

IEEE TRANSACTIONS ON POWER DELIVERY

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1 - 10

Autor (5)






Jednostka badawcza


Katedra Energoelektroniki i Maszyn Elektrycznych
Katedra Inżynierii Elektrycznej Transportu

Wydział


Wydział Elektrotechniki i Automatyki