Research On Demand Response Potential Evaluation And Aggregated Control Of Inverter Air-conditioning

with the continuous increase in the penetration rate of intermittent renewable energy,the power fluctuation of the grid has increased,and the operation and the dispatch of the power system is facing new challenges.Demand response as one of the key technologies of the internet of Things and smart grid can effectively improve energy efficiency of systems,and the inverter air-conditioning loads have been considered as a high-quality demand side resources and assist in balancing the power supply and demand through reasonable dispatch.However,the unit power of inverter air conditioner is small and the number is huge.How to effectively evaluate the response potential of large-scale inverter air conditioner load group and establish a control-oriented aggregation model is still an urgent problem to be solved.This paper focuses on the control mode,response mechanism,response potential evaluation,aggregation modeling method and cluster control strategy of inverter air-conditioning loads participating in demand response.The main research contents are as follows:Firstly,a frequency control strategy based on variable slope coefficient is proposed to solve the problem of load power fluctuation of inverter air-conditioning.In order to describe the heat conduction process between indoor air and solid matter and improve the accuracy of the model,a load model of inverter air-conditioning is established based on the second-order equivalent thermal parameter model;Based on the analysis of the mechanism and control mode of inverter air-conditioning load participating in demand response,combined with the advantages of conventional temperature control and frequency control,and considering the user comfort,a frequency control strategy based on changing the slope of frequency characteristic curve is proposed.The simulation results show that the load model of inverter air-conditioning can accurately describe the temperature change of room and solid matter.The frequency control strategy based on variable slope coefficient not only eliminates power fluctuation,but also realizes continuous frequency regulation.Secondly,in view of the lack of unified potential assessment method for inverter air-conditioning load,a new method for evaluating the demand response potential of large-scale inverter air-conditioning load group is proposed.The relevant potential evaluation indicators are defined,and various aspects of the performance of large-scale inverter air-conditioning load group participating in demand response are quantitatively evaluated.At the same time,the influence of different external factors on the demand response potential of load group is analyzed.The simulation results show that the proposed demand response potential evaluation method can effectively evaluate the potential of large-scale inverter air conditioner load groups participating in demand response under different environments and user conditions,and reduces the risk of load fluctuation caused by the unpredictable load of inverter air-conditioning.Finally,in view of the lack of a control-oriented aggregation modeling method for inverter air-conditioning,a control-oriented aggregate inverter air-conditioning load model is established,and a power tracking control algorithm for aggregate inverter air-conditioning based on reverse control is designed.The key to the participation of large-scale inverter air-conditioning in system regulation is to establish a control-oriented aggregation model.In this paper,based on the change rate of frequency set value,the load dynamic transmission model of inverter air-conditioning is established.The free response model and forced response model of aggregate inverter air-conditioning load are obtained by using finite difference method;Based on the backstepping control principle,the load power tracking control algorithm of the aggregate inverter air-conditioning load is designed,and its convergence is proved by Lyapunov stability theory.The simulation results show that the aggregation model can characterize the load characteristics of the inverter air-conditioning cluster,and the electrical relationship between frequency and temperature difference can be changed through the control algorithm,and finally the fast and accurate tracking of the power reference curve is realized,which effectively improves the demand response effect.Through the research of the inverter air-conditioning load aggregation model and cluster control strategy,this paper provides a model and control basis for the inverter air-conditioning load to participate in the auxiliary services of the power system,and provides a new solution for the promotion of demand-side resources as a control method to support the power balance of the power system.