A novel Isolated Four-Switch High Gain Buck-Boost DC-DC Converter featuring a Continuous Input Current operation and novel allied Converter for Multi-output characteristic

In this paper, a novel isolated four-switch enhanced gain buck-boost DC-DC converter for Medium Voltage Direct Current (MVDC) transmission is presented. The proposed converter consists of input inductor interfacing the Battery Energy Storage Systems (BESS) with the MVDC bus, which renders continuous source current operation and hence allows for longevity of the input battery. This feature also allows for seamless integration into DC microgrid sources with intermittent supply. Detailed steady-state continuous conduction mode operation and waveforms have also been derived for the converter and simulated in the MATLAB
^®
/Simulink simulation platform. This paper reports a novel allied converter of two inductors and two capacitors, featured in parallel with the converter input to ensure multi-output functionality with multiple ports supplying output DC power, thus ensuring high redundancy. The capacitor bank at the input of the main converter provides the ripple current for the allied converter and hence the battery life is improved. A steady-state analysis of the allied converter is also reported in detail along with multi-output features. Closed loop control dynamics of the allied converter along with voltage controller design is also presented and thus, the rigidity and robustness of the system is improved.