Distributed Optimal Scheduling in Community-Scale Microgrids

Secondary and tertiary control of microgrids is often centralized and requires system-wide measurements and communication between entities. Such approaches can be susceptible to single points of failure especially when communication infrastructure is not reliable. Self-organizing local electrical energy network (SOLEEN) is a secondary control framework which ensures operational sufficiency of the network without any central control or communication. Higher layers of control can be overlaid on SOLEEN for optimal operation. This paper presents a distributed approach for realizing tertiary control of SOLEEN-based dc community microgrids through an optimal scheduler at each entity for local loads and energy exchange with the network. The scheduler uses integer linear programming to meet the objectives of the entity such as revenue generation and maximizing service to critical loads. The model provides parameters to account for socio-economic differences across participating entities which can result in different objectives. It is independent of network topology, variations in local power sources, making it a plug-n-play option for resource-constrained deployments in rural communities. The model is verified through computer simulations and experiments on a hardware-in-the-loop setup.