Optimal Primary Frequency Reserve Provision by an Aggregator Considering Nonlinear Unit Dynamics

Power system operators are increasingly procuring frequency regulation reserves from distributed energy resources via aggregators. Provision of the frequency regulation services by the aggregators can be studied from different aspects and by using different models, ranging from very-short-run to long-term scheduling models. By developing a methodology for ensuring the operational model's compliance with the dynamic constraints, this paper bridges the gap between economic studies of the aggregator's frequency containment reserve market participation on the one hand and the distributed energy resources' dynamic response on the other. The paper presents a mixed-integer linear program for the aggregator's portfolio management that incorporates constraints of individual units' fast dynamics, and validates them via dynamic simulations. The results demonstrate the importance of including reserve activation constraints when modelling storage technologies and settling time constraints when modelling conventional units.