A list of three novel dissimilar voltage multi-input isolated high gain DC-DC converters supplying multiple outputs with widely varying characteristics

This paper explores three novel isolated Direct Current- Direct Current (DC-DC) converters with high gain and varying characteristics, fed from two unequal battery voltages. The two degrees of freedom in terms of the per unit duty cycle and the turns ratio <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$N$</tex> of the High-Frequency Transformer (HFT) help in providing a high gain isolated output voltage in Continuous Conduction Mode (CCM) with varying characteristics of derived Boost and Buck-boost. The isolated port output voltage for one of the converters is independent of Vin2 while for another it is the enhanced gain non-inverting buck-boost for a source voltage equal to an average of Vin1 and Vin2. The input current continuity of the converters (for possibilities of seamless renewable integration e.g. Solar Photovoltaic Array) and the OFF-state voltage stresses for all the power electronic switches in the converters are comparatively investigated. Steady-state CCM mode analyses for all the converters are presented in detail and the voltage gains at all output ports are derived respectively. MATLAB® SIMULINK Simulation platform is used to simulate the converters to validate the theoretical analysis. An average closed-loop current controller is designed and its efficacy is verified using step load changes. In summary, a list of three novel isolated DC-DC converters fed from dissimilar input battery voltages are presented in this paper which cater to enhanced gain buck-boost and boost characteristics and can cater to widely varying applications.