Robust Energy-Constrained Frequency Reserves from Aggregations of Commercial Buildings
For power system operators and building aggregators, this framework enables reliable provision of frequency reserves from commercial buildings, addressing the challenge of energy constraints in reserve signals.
The paper proposes a hierarchical control framework for scheduling and providing frequency reserves from commercial building HVAC systems, incorporating energy-constrained signals. Simulations with Swiss office buildings show that an aggregation of about 100 buildings can meet the 5 MW minimum bid size for the Swiss reserve market.
It has been shown that the heating, ventilation, and air conditioning (HVAC) systems of commercial buildings can offer ancillary services to power systems without loss of comfort. In this paper, we propose a new control framework for reliable scheduling and provision of frequency reserves by aggregations of commercial buildings. The framework incorporates energy-constrained frequency signals, which are adopted by several transmission system operators for loads and storage devices. We use a hierarchical approach with three levels: (i) reserve capacities are allocated among buildings (e.g., on a daily basis) using techniques from robust optimization, (ii) a robust model predictive controller optimizes the HVAC system consumption typically every 30 minutes, and (iii) a feedback controller adjusts the consumption to provide reserves in real time. We demonstrate how the framework can be used to estimate the reserve capacities in simulations with typical Swiss office buildings and different reserve product characteristics. Our results show that an aggregation of approximately 100 buildings suffices to meet the 5 MW minimum bid size of the Swiss reserve market.