Research On Aggregated Operational Characteristics And Uncertainties Of Demand Side Resources

Under the goal of "double carbon",demand response(DR)becomes a very important technology in the power system.Due to the continuous improvement of living standards and the adjustment of industrial structure,the peak-valley difference of power load is constantly increasing.If the power generation side is adjusted to meet the demand of electricity,the power grid has to leave a certain amount of redundant generating capacity,which is bound to cause a waste of resources.While the total power loads increase,the proportion of flexible loads increase year by year,and the demand response of the power side can be used to adjust the balance of power supply and demand.However,uncertainties in the demand response process are inevitable,ignoring the influence of uncertainties will lead to the risk of power grid operation.In this thesis,the operational characteristics and uncertainties of demand-side resources(DSRs)are studied to provide a basis for the management and utilization of DSRs by power grid.The main work is as follows:Firstly,considering the wide varieties,large quantity and different characteristics of DSRs,the DSRs studied in this thesis are divided into temperature-controlled loads(TCLs),electric vehicles(EVs)and other reducible loads.Then,studying the modeling basis of various loads,analyzing the characteristics of typical loads and established their aggregation models with random factors.On the basis of the characteristics of various controllable loads,the methods of evaluating the adjustable potential of various loads are studied.Secondly,since the demand response potential of each load is strongly uncertain due to the influence of users’ behavior and external factors.Considering the multiple uncertainties of each load when participating in the response,the dynamic process of response of each load is analyzed.Based on given baseline of each load,using Monte Carlo simulation(MCS)method to simulate multiple comprehensive dynamic aggregation of each load power under the influence of all random factors,and the multistate model(MSM)of aggregation response capacity of various load is established.The state of response capacity is divided according to the standard deviation of response capacity fluctuation,and the state of response capacity in each period and its corresponding probability are obtained.For the resources connected to the same location in the distribution network,considering the interaction between resources,the response capacity probability distribution sequence of each resource at the same time is convolved,and the aggregated response capacity multi-state model of multiple types of resources is obtained.Finally,based on the response uncertainties of each load,the influence of controllable loads’ participation in demand response on the operation quality of the power system is analyzed.The simulation is carried out in the CIGRE example.Based on the MSM of response capacity,the loss of load probability(LOLP)of node and the expected energy not served(EENS)considering whether the controllable resources participated in DR are calculated by the weighted method,so as to evaluate the reliability improvement of the power grid;Similarly,the voltage deviation of each node and the system voltage deviation level considering whether the controllable resources participated in DR are calculated to evaluate the improvement of the power quality of the power grid.The simulation results show that demand response can obviously improve the operational quality of power grid.In addition,build a display platform for the aggregated operation results of all controllable resources,so that users can directly set the location of access distribution network and aggregate size of each resource.The MATLAB GUI function is used to encapsulate it into a simple,intuitive,easy to expand and efficient graphical interface that can interact with users.