Design of Aggregators for the Day-Ahead Management of Microgrids Providing Active and Reactive Power Services

Microgrids (MGs) are an interesting solution to locally manage distributed generation, but they are not usually designed to provide significant contribution in terms of external ancillary services to the main grid. In this brief, we propose a framework for the aggregation, coordination, and day-ahead scheduling of interconnected MGs to provide external services, such as the power-reserve provision. The framework is structured in three phases. In the first one, a distributed optimization algorithm computes the day-ahead profile of the active power production of the MGs based on the available forecasts. Scalability of the optimization problem and confidentiality requirements are guaranteed. In the second phase, reactive power flows are scheduled while ensuring that the active power trends planned in the first phase do not compromise voltage/current limitations. The third phase is used to schedule the active and reactive power profiles of the generation units of each MG to make them consistent with the requirements and results of the previous two phases.