Technical Articles

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Analytical Modelling in Single-Phase and Three-Phase DC/DC LLC Converters

Technical Article – Authors: M. Marceau – H. Huillet – P. Marchand


This paper exposes the analysis, modeling and comparison of two different LLC converter configurations: the conventional LLC converter and the Three-Phase YΔ LLC converter, which is firstly analyzed in this paper. Piecewise-defined analytical equations that accurately model the behavior of these converters have been developed and validated through simulation. Additionally, a comparison between these two power converters has been carried out, so the advantages and disadvantages of each of them are exposed. To validate the derived conclusions, a fully optimized Three-Phase YΔ LLC converter is designed (including the design of the resonant tank, the three-phase transformer, the resonant inductor, and the selection of semiconductor devices) and compared to a 96% efficiency single-phase LLC converter.