Autonomous Control Strategies for Interconnected DC Microgrids with Geographical Separation

Distributed Energy Resources (DER) with renewable energy sources are propagating quickly and as such, research for integrating these new technologies more efficiently and reliably is paramount to a well working grid. A significant amount of energy is produced and stored in DERs as Direct Current (DC). DC microgrids are being studied as an alternative to Alternating Current (AC) microgrids due to their increased efficiency and simplicity of control. Microgrids are usually controlled by broadband communications, but some forms of autonomous control have been developed as contingency for loss of communications scenarios. Previously developed autonomous controls have been shown in practice to work well for close proximity interconnected grids. However, geographical separation of assets is generally not considered. This paper presents simulation results for an autonomous control strategy to interconnect geographically extended microgrids through aerial and underground power lines, with the use of averaged bidirectional boost converters.