Fully Distributed Controller for Economic Load Sharing of DC Microgrid Clusters

A fully distributed hierarchal controller is proposed to minimize the total generation cost (TGC) for multiple interconnected DC microgrids (MGs) cluster. It consists of global and local control levels while a two-layer sparse communication network is modeled for information sharing with a reduced complexity. The global control level, in a fully distributed manner, optimizes the power flow among MGs and defines the economic operating point of each MG by determining the optimum incremental cost (IC) value of the entire cluster. The distributed local control level not only matches the ICs of all DGs in the MG with the global assigned optimum IC to accomplish the lowest TGC of the cluster, but also guarantees generation-demand equilibrium in the MG and sequentially within the entire cluster. Feasibility of the proposed controller in case of load variations, plug-n-play capability, and communication failures are verified using hardware in the loop (HIL) prototype.