A Novel Four-Switch DC-DC Converter Using Stacked Non-Isolated Boost and Switched Flyback Converters For High Battery Current Application

In this paper, a novel four-switch DC-DC converter is explored, using a stacked non-isolated boost and a switched isolated converter. An extra flyback branch is introduced in cascade to the conventional synchronous boost converter to provide for a high step-up application using Input Parallel Output Series (IPOS) - derived variant. This converter can provide for high input current applications like Electric Vehicle drivetrain for high power low voltage battery catering. Input capacitor to the converters allows for continuous input current from the battery and hence ensures extended battery life. Both subtractive and additive output series voltages are presented in this paper. Also, a different switching combination that allows the converter to operate as a two-port network for both the additive and subtractive series topologies is also presented in this paper. Due to the presence of Right Half Plane (RHP) zero in its voltage-to-output small signal transfer function, detailed closed-loop current control is presented and simulation waveforms using MATLAB/SIMULINK platform are also explored in this paper. The efficacy of the designed current controller is checked using step changes in load. In summary, this paper caters to IPOS-derived variants that can cater to a high battery current application and can also provide high voltage gain for one-port as well as a two-port output load.