Frequency Control using Cooperative Demand Response through Accumulated Energy

This paper proposes a hierarchical control architecture for engaging demand into providing primary frequency response services. The proposed architecture relies on the use of information about accumulated energy for the aggregation of demand capabilities and dissagregation of demand responsibilities. Since the accumulated energy has a distinct additive property, the aggregation/disaggregation of demand becomes straightforward. Additional unique features of the proposed architecture are that it: i) includes the information of inflexible load in the aggregated demand, ii) allows for intuitive cooperation between load aggregators. Conditions for stability under cooperating load aggregators are derived. Finally, simulations are carried out on the IEEE 39-bus system to illustrate the proposed concepts of aggregation, disaggregation and cooperation.