Robust Reserve Provision by Commercial Buildings Considering Energy-Constrained Frequency Signals

It has been shown that the heating, ventilation, and air conditioning (HVAC) systems of commercial buildings can offer ancillary services to power systems due to their large thermal inertia. In this paper, we propose a new control framework for scheduling and provision of frequency reserves by commercial building aggregations. The framework builds on a hierarchical control scheme: first, the reserve capacities are allocated among the buildings, e.g., on a daily basis, using techniques from robust optimization; second, a robust model predictive controller optimizes the HVAC system consumption typically every 30 minutes; and third, a feedback controller adjusts the consumption to provide reserves in real time. The framework incorporates methods for energy-constrained frequency signals, which are currently adopted by several transmission system operators for loads or storages. The proposed framework can be used to estimate the amount of reserves that can be extracted from commercial buildings, and we demonstrate its performance in simulations considering different building types and reserve characteristics. Our results indicate that, depending on the season, aggregations of 35−150 commercial buildings with an average floor area of 15000 m are enough to participate in reserve markets with a minimum bid size of 5 MW and products for energy-constrained frequency signals.