Analysis of Consensus-Based Islanded Microgrids Subject to Unexpected Electrical and Communication Partitions

Abstract

Microgrids (MGs) are power systems consisting of an electrical network composed by distributed loads and generation units that may include a communication network for improved operation. The considered MG in islanded mode is driven by voltage source inverters implementing decentralized droop control for active power sharing together with a communication-based consensus algorithm for frequency regulation. This paper analyzes the MG performance subject to network failures that provoke network partitions. It is considered that the electrical partition leads to several sub-MGs working in parallel where the power demand can be always guaranteed by the generation units, and the communication partition leads to several consensus algorithms also working in parallel. The double partitioning is analyzed through a closed-loop system model derived using the power flow equations that includes the electrical and communication connectivity. Analytical expressions for the steady-state values for both frequency and active power depending on the partitioning are derived. Selected experimental results on a low-scale laboratory MG illustrate the (undesirable) impact that unexpected partitions have in system performance.