  This work proposes a geographically-based split of the community microgrids
into clusters of members that tend to have similar consumption and generation
profiles. Assuming a community microgrid divided into clusters, a two-layer
architecture is developed to facilitate the greater penetration of distributed
energy resources in an efficient way. The first layer, referred as the market
layer, is responsible for creating local energy markets with the aim of
maximising the economic benefits for community microgrid members. The second
layer is responsible for the network reconfiguration, which is based on the
energy balance within each cluster. This layer complies with the IEC 61850
communication standard, in order to control commercial sectionalizing and tie
switches. This allows the community microgrid network to be reconfigured to
minimise energy exchanges with the main grid. To implement this two-layer
energy management strategy, an aperiodic market approach based on Blockchain
technology, and the additional functionality offered by Smart Contracts is
adopted. This embraces the concept of energy communities since it decentralizes
the control and eliminates intermediaries. The use of aperiodic control
techniques helps to overcome the challenges of using Blockchain technology in
terms of storage, computational requirements and member privacy. The
scalability and modularity of the Smart Contract-based system allow each
cluster of members to be designed by tailoring the system to their specific
needs. The implementation of this strategy is based on low-cost off-the-shelf
devices, such as Raspberry Pi 4 Model B boards, which operate as Blockchain
nodes of community microgrid members. Finally, the strategy has been validated
by emulating two use cases based on the IEEE 123-node system network model
highlighting the benefits of the proposal.
