Demand Response Load Following of Source and Load Systems

This paper presents a demand response load following strategy for an interconnected source and load system, in which we utilize traditional units and population of cooling thermostatically controlled loads (TCLs) to follow the mismatched power caused by the load activities and the renewable power injection in real time. In the demand side of power systems, these TCLs are often affiliated to a bus load agent and can be aggregated to multiple TCL aggregators. First, aggregate evaluation of the TCL aggregator is carried out based on a bilinear aggregate model so as to derive the available regulation capacities and regulation rates of aggregators. Based on the evaluation results, the dispatch center optimizes the real-time load following trajectories for the generating units and the flexible load agents via look-ahead optimization by considering the injection of renewable power. Furthermore, we mainly focused on the distributed control of multiple TCL aggregators. By proposing a distributed pinning control strategy and designing a spare communication network among the aggregators, the reference power tracking of the load agent can be shared by all aggregators inside it in a distributed way. Finally, simulation results on a modified IEEE-9 bus system are provided to demonstrate the effectiveness of the proposed load following strategy.