An LLC-DAB Hybrid Converter With High Inputoutput Voltage Ratio Based on an Integrated Matrix Transformer

The LLC-DAB hybrid topology attains voltage regulation capability, while the LLC operates at a resonant frequency for high efficiency. In applications featuring a high ratio of the input to output voltage, the series and parallel multiple transformers can effectively reduce the voltage and current stress of the transformer. However, the large quantity of transformer units and bulky magnetic components result in low power density and low efficiency. Therefore, the planar magnetic integrated matrix transformer is adopted to solve these problems. This article gives the operation principle of an LLC-DAB hybrid converter, and a six-leg integrated matrix transformer is designed for a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2.5 ~\text{kW} 750 ~\mathrm{V} / 48 ~\mathrm{V}$</tex> LLC-DAB hybrid topology. Further optimization of the core based on loss is given. The decoupling conditions are given according to the simplified magnetic circuit model. A simulation model is built in ANSYS Maxwell software. Simulation results demonstrate the effectiveness of the proposed matrix transformer structure.