A multiple-input SEPIC with a bi-directional input for modular distributed generation and energy storage integration

This paper improves the design of a previously proposed multiple-input SEPIC by providing bi-directional power flow capabilities in order to integrate energy storage devices with distributed generation sources. In this work an ultra-capacitor bank is considered as the multiple-input SEPIC energy storage input and auxiliary power source. When the main source generates enough power to regulate the output voltage by itself, energy is stored in the ultra-capacitor bank in order to provide auxiliary power for periods when the main generation source is insufficient. The proposed converter is described by its fundamental equations in both charging and discharging modes. Analysis evaluation through simulation and hardware experiments is also performed.