Asynchronous Communication-Based Distributed Control Strategy for ON/OFF State Thermostatically Controlled Loads

Thermostatically controlled loads (TCLs) obtain significant potential for providing auxiliary services to the power grid. Aggregators typically utilize centralized strategies when implementing direct load control (DLC) to manage TCLs, but these strategies consume substantial communication resources when dealing with large-scale TCLs. This paper proposes a distributed control strategy for ON/OFF state TCLs to alleviate the aggregator’s communication burden. The concept of temperature-based priority is introduced to ensure fair scheduling among TCLs. TCLs can determine their priority order in the cluster by communicating with neighboring TCLs and locally decide their operation states to achieve reference power tracking. A sub-priorities splitting method is introduced to further enhance power tracking accuracy. Furthermore, the proposed strategy utilizes an asynchronous communication mechanism in the coordination process, making it highly suitable for practical implementation. The study conducts numerical simulations and semi-physical experiments to validate the practical feasibility of the proposed strategy. The results conclusively demonstrate that the proposed strategy can effectively achieve accurate reference power tracking by the TCLs cluster.