A Predictive Energy Management System Using Pre-Emptive Load Shedding for Islanded Photovoltaic Microgrids

This paper presents an energy management system (EMS) for an islanded microgrid with photovoltaic generation and battery storage. The system uses a predictive approach to set operational schedules in order to minimize system-wide outages in the microgrid, specifically through pre-emptive load shedding. Four-times daily updated online weather forecasts are combined with the photovoltaic system model to predict energy production over a 48 h period. These predictions are used, along with load forecasts and a model of the energy storage system, to predict the state-of-charge and characterize potential upcoming outages. Outage mitigation actions using pre-emptive load shedding are then planned and executed to avoid outages or minimize the duration of unavoidable outages. The approach also features bounds on the battery state-of-charge to account for uncertainties in the estimate of the stored energy. The EMS has been implemented using an event-driven framework with TCP/IP communication, which is modular and extensible to more complex system configurations. The approach has been validated through simulations and experiments, which demonstrate its feasibility and potential, for the chosen test scenario, to reduce the outage duration by 87% to 100%.