A High Step-down DC-DC Converter with Matrix-Transformer and Wide Voltage Gain for Vehicle Power Supply Applications

A two-stage high step-down DC-DC converter with matrix-transformer is presented for vehicle power supply applications. Wide voltage gain is achieved by the front-end Boost converter and down-stream phase-shifted full-bridge converter. With the novel two-stage structure, the input voltage range of the down-stream full-bridge converter is narrowed significantly, which helps to reduce the current stress of primary switches and the voltage stress of the secondary switches. Devices with better performances can be chosen and high efficiency power conversion is achieved with the presented topology. Furthermore, the matrix-transformer is used in full-bridge converter to handle the large output current, which is beneficial for simplifying the design and processing of the transformer. Meanwhile, the current sharing of transformer windings will not be considered. Operation principles and characteristics of this converter are analyzed in detail. Experimental results are provided to evaluate the effectiveness of the presented solutions.