Using Controlled Thermostatic Loads in Buildings as Auxiliary Services to the Power Grid: An Investigation With Thoroughly Simulated Case Study

The massive integration of renewable energy sources poses increased power generation fluctuations, necessitating enhanced regulation capacities to maintain a power balance in supply and demand. Beyond conventional generators, advanced information and communication technologies offer an alternative approach, utilizing flexible loads, mainly thermostatically controlled loads (TCLs) of buildings for grid regulation services. TCLs garner significant attention due to their unique thermal inertia capability in demand response (DR) programs. However, to manage the distributed TCLs effectively, it is vital to study the performance of the aggregator, which acts as a bridge between the grid operator and end-users and thus assumes a pivotal role in the management of TCLs. This paper extensively reviews and compares fundamental technologies inherent to TCLs within the context of DR applications, covering basic models, response modes, control techniques, dispatch models, and strategies. Further, the review explores these critical aspects and addresses current challenges and potential prospects. Moreover, as an illustration, the study has developed and analyzed a comprehensive model of the automatic generation control (AGC) system to integrate TCLs for power balancing services in large-scale wind energy-integrated power systems. A power dispatch strategy has been designed for the AGC model to integrate the loading capacities of TCLs in providing grid ancillary services. The designed dispatch strategy prioritizes utilizing TCL capacity over conventional generating units, reducing the overall operation cost, and decreasing the grid’s dependency on conventional power plans. DigSilent PowerFactory software was used to obtain the simulation results, demonstrating the significant efficacy of aggregated TCL response in actively contributing to power support during grid balancing services.