This paper exposes the analysis, modeling and comparison of two different LLC converter configurations: the conventional LLC converter and the Three-Phase Y−Δ 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 Y−Δ 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.