Journal article Open Access
Hierarchical control schemes have been commonly employed in DC microgrid controls, which combine local control, DC bus voltage coordination and communication links to guarantee smart operation of DC microgrids. Conventional DC bus voltage regulation cannot conduct signal exchange. Therefore, external communication links are usually needed for hierarchical control schemes. However, once the communication link fails, the hierarchical control system will lose its ability to coordinate the distributed power smartly. This paper proposed a dual-window DC bus interacting (DBI) method to exchange information between the distributed energy sources, for the situations where communication link fails or is not available. A small-scale DC microgrid experimental system was setup, and a simple Master-Slave control scheme is implemented without communication link to demonstrate the feasibility of the proposed DBI method for DC microgrid controls. The expandability and immunity of the proposed DBI method were also evaluated.