Time-Domain Model of the SRC-LLC Resonant Converter with Variable Frequency and Single Phase Shifted Control

Abstract

SRC-LLC resonant converter has attracted much attention due to its simple circuit structure and easy realization of soft-switching. To get a better efficiency performance, rectifier stage can be realized by active switches instead of the diodes. With different modulation control strategy, the converter will show variety kinds of gain features. This paper will make a research on the gain features of the SRC-LLC converter with both variable frequency (VF) and phase shifted (PS) control. For the consideration of simple control, only single phase shifted (SPS) control is applied. Different from the common modeling method with the Fundamental Harmonic Approximation (FHA), the accurate time-domain model is investigated. At last, the theoretical results are verified by both the simulation and the experiment results.