A Novel Six-Switch Two-Output Port Isolated DC-DC Converter Acting as a DC Transformer for Battery Voltage Step-Up and Battery-to-PV Changeover Applications

This paper proposes a novel isolated six-switch DC-DC converter, consisting of two output ports - one isolated and one non-isolated, at different voltage levels catering to diverse voltage applications. The non-isolated port allows for an inverted buck-boost operation, whilst the isolated port with a secondary-to-primary High-Frequency Transformer (HFT) turns ratio <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$N$</tex> exhibits a pure DC transformer operation with a non-inverted polarity, i.e. its output voltage scales the input battery voltage by a factor of N. Continuous Conduction Mode (CCM) steady-state analysis of the converter is detailed and MATLAB® SIMULINK simulation waveforms for the converter operation under various modes are outlined. The closed-loop current controller is designed and tested with step load changes and the switchover from the battery-fed system to a Photovoltaic (PV) array is displayed to ensure its efficacy.