A Consensus-Based Cooperative Control for DC Microgrids Interlinked via Multiple Converters

Abstract

In the clustered dc microgrids (MGs), two dc MGs can be connected through multiple interlinking converters (ICs) in order to increase system power capacity as well as to achieve a better efficiency, reliability, and stability. This is more common for high-power dc MGs. The conventional droop control strategy is not a practical choice for providing proportional power sharing among two dc MGs with more than two ICs. This is mainly due to either differences in transmission line impedances or different output impedances of the ICs which can result in an unwanted circulating current among them. In this article, a two-level control scheme in a fully distributed manner is proposed for interconnecting two dc MGs by multiple ICs. The proposed scheme is based on the consensus protocol which only requires local measurement and neighbor information through a sparse communication structure. This control scheme proportionally shares power not only between two dc MGs but also among the multiple ICs and suppresses the circulating currents as well. A complete set of simulation studies is carried out in PLECS (Plexim) software to verify the effectiveness of the proposed control scheme.