Hierarchical control strategy for residential demand response considering time-varying aggregated capacity

Load control strategy has become a focus of researches, as demand-side resources are technically and economically desirable to relieve system power imbalance. In this paper, a hierarchical control strategy via load aggregator (LA) is proposed, considering both the evaluation of potential response capacity of large-scale residential loads and optimal allocation of response demand to each individual load. First, an aggregate model is established to exploit the time-varying potential response capacity of a population of residential loads. In the upper strategy, an equivalent response potential (ERP) index is created to quantitatively calculate the aggregate capacity and utilized to guide the allocation of total response demand to each LA. In the lower strategy, an optimal allocation model is built to determine the response status of each residential load per minute, ensuring end-user satisfaction and demand response requirements. The aggregate model and control strategy are verified valid through case studies. Furthermore, model accuracy and strategy implementation are discussed as well.