Distributed Coordination of Networked Microgrids for Voltage Support in Bulk Power Grids.

The increasing deployment of distributed energy resources (DERs) and microgrids (MGs) in power distribution systems has enabled the adjustment of reactive power consumption as seen at the substation, which can be used to provide voltage support for the bulk power system (BPS). Leveraging this new capability will provide greater resiliency to the power system as a whole. The goal of this paper is to discuss three different algorithms which use networked MGs to support the BPS voltage when a contingency at the bulk grid results in abnormally low voltages, which may be a precursor to voltage collapse. These algorithms are (1) distributed optimal power flow, (2) distributed consensus, and (3) fully decentralized collaborative autonomy. Our comparitive analysis includes both qualitative and quantitative assessment of the three algorithms and a discussion on the trade-offs between the decentralized and distributed methods. Each algorithm was evaluated on the IEEE 13-bus system modified to include 5 connected MGs and a Théevenin equivalent of the BPS. It was found that each of the algorithms excels in different ways and may be used under different scenarios depending on the state, operations, and priorities of the power and communication systems.