Analytical model of a phase-shift controlled three-level zero-voltage switching converter

Soft-switching of resonant dc-dc converters is used to enable high switching-frequencies and miniaturization of filter components. These converters are typically modeled using a first-harmonic approximation. This results in generalization of the operating modes, by only using the first harmonic of the converter. In this paper a phase-shift controlled series-resonant converter is analyzed per operating mode using an accurate analysis. For each operating mode, an analytical expression is derived resulting in a more accurate representation of the converter behavior when compared to first-harmonic approximation. Experimental results show that the model accurately predicts the converter.