Studies On The Dynamic Demand Response Theory Of Air-conditioning Loads And Its Application

With the development of national economy, the demand of electricity increases rapidly, which threats the electricity supply-demand balance. The air-conditioning usage amount increases due to the frequent cases of extreme weather so air-conditioning loads has been a key component of peak load in summer and winter. As a thermostatically controlled load (TCL),air-conditioning loads can convert electric power into thermal energy stored in room, which makes it the most potential loads to participate in demand response programs. By reasonable controlling air-conditioning load, peaks could be reduced and balance be achieved between supply and demand at lower cost without affecting users' comfort. Air-conditioning load is numerous and can be controlled flexibly so it is fundamental to study the models and application of ACs.Firstly, equivalent thermal parameters model (ETP model) for single AC was introduced and the control models for aggregated ACs were overviewed. Then, two advanced control models for aggregated ACs were proposed and applied in load shifting and secondary frequency control separately. Finally, a new demand response program called Progressive Time-differentiated Peak Pricing for Air-conditioning load is designed. All the specific contents are arranged as follows:1. We propose a friendly temperature adjusting method to avoid load oscillations by separately controlling top and bottom limitations of temperature setpoint. Then the load dispatch decision model is designed accordingly. At last, through simulation example, this paper analyze the influence of dispatch plan, aggregate group and dispatch target on scheduling result, proved the feasibility of the load dispatch decision model, which provide a method to integrate air-conditioning loads into power system operation.2. We present a control framework integrating the supplementary secondary frequency control with the traditional secondary frequency control. Then a change-time-priority-list method is proposed to control power output taking into account customers' satisfaction.Simulations on a single-area power system with wind power integration demonstrate the effectiveness of the proposed method. The impact of ambient temperature changes and customer preferences on room temperature is also involved in the discussion. Results show that the supplementary secondary frequency control provided by ACs could closely track the secondary frequency control signals and effectively reduce the frequency deviation.3. The control method to provide secondary frequency control with ACs and battery energy storage system (BESS) is proposed with the designs of BESS control strategy and ACE signal distributor. Case simulation on a two-area power system is carried out to validate the role played by the method in bringing the active effectiveness to frequency regulation considering energy storage capacity, the charge and discharge power of energy storage and.4. The relationship between the electricity price and the temperature setpoint of Air-conditioning is described by the consumer psychology theory, and the baseline model of the aggregated Air-conditioning is built on the basis of equivalent thermal parameters model.Then a new demand response program called Progressive Time-differentiated Peak Pricing for Air-conditioning load is designed accordingly. At last, through simulation example, this paper compares the implementation effect of the Time-differentiated Peak Pricing with that of the conventional Critical Peak Pricing and proved the feasibility of the price mechanism. The influence of different price shapes and different compositions of consumers on simulation results is analyzed, which provides the theoretical basis and reference data for the practical implementation of Time-differentiated Peak Pricing.