Price-optimal Energy Flow Control of a Building Microgrid Connected to a Smart Grid

This paper discusses model predictive control for energy flows in a microgrid as a part of the overall hierarchical organization of energy management in a building. The control is performed in the presence of time-varying building and grid conditions: weather-dependent production, energy prices and consumption. Detailed analysis of microgrid energy and operation cost is presented with real weather data and energy prices, building dynamics and optimal building consumption. Cost-optimal interaction between the buildingside energy management system and the grid in conditions of volatile energy price and possibility of building's active participation in the energy market is proposed. Model predictive controller for optimizing total economic cost of energy and microgrid operation is implemented and verified on a model of a building belonging to University of Zagreb, Faculty of Electrical Engineering and Computing, using actual test site data for 2014. Reduction of maximum power, minimization of energy consumption, storage degradation during operation, day-ahead energy profile following and intra-day deviations as energy market incentives are included in the cost function for ensuring building ancillary services as a prosumer in the smart grid.