Operation schemes of interconnected DC microgrids through an isolated bi-directional DC-DC converter

This paper presents interconnection of DC microgrids at the low-voltage DC bus level through an isolated bi-directional DC-DC converter. The purpose of the interconnection is to overcome inherent limitations of a single DC microgrid such as power variation and finite capacity of distributed sources. The operation schemes of the proposed systems are based on the DC bus signaling with the object of efficient power transfer and high quality of DC bus voltage. Direct and bi-directional power conversions between adjacent DC microgrids have been proved to improve reliability of each microgrid and efficiency of the entire system. Experimental results measured from a laboratory set-up verified the feasibility of the proposed approaches.