Demand-side management of air conditioning cooling loads for intra-hour load balancing

This paper evaluates the performance of a centralized load controller designed to provide intra-hour load balancing services (LBSs) using air conditioning (a/c) units in their cooling modes. First, thermal models of a/c units and the control logic of the central controller are presented. The objective is to control the aggregated consumption of the thermostatically controlled appliances (TCAs) to follow a desired load profile for providing LBSs. The simulations are carried out in a MATLAB/Simulink environment. A total of 1000 a/c units in their cooling modes are modeled to provide a realistic ±1 MW load balancing signal for 24 hours for baseline settings. The impacts of lockout times, ambient temperatures, heat gains, and two-way communication delays on the demand-side management (DSM) performance are modeled. The cost of communication between the TCAs and the central controller, customer comfort, device life cycles, and control errors are used as metrics to evaluate the DSM performance. The results demonstrate that the DSM controller precisely controls the aggregated heating, ventilating, and air conditioning load shapes while maintaining load diversity. The controllable and the measurable load services that the controller provides can be used for many other demand response applications, such as peak shaving, load shifting, and arbitrage.