| With the rapid development of new-type urbanization,the energy structure is gradually transformed,accelerating the diversified development of various energy forms such as electricity,natural gas and thermal energy.Therefore,the traditional discrete energy supply system should be transformed for the single energy operation mode and low energy utilization rate,and a comprehensive energy system that considers the coordination and complementarity of multiple energy sources becomes the mainstream of future energy system development.The integrated energy system uses energy aggregation technology,which integrates a variety of distributed energy equipment to coordinate and dispatch uniformly,effectively improving the economics and flexibility of system operation,and achieving energy utilization efficiently.But at the same time,due to the aggregation of multiple energy forms,it also brings great challenges to the safe operation of the integrated energy system.On the one hand,the output of the distributed new energy units in the system fluctuates greatly with the impact of the environment,increasing the integrated energy system uncertainty on the power side;on the other hand,with the development of multiple energy forms,the energy consumption behavior also exhibits diversified characteristics.The temporal and spatial uncertainty of energy consumption behavior and the multi-energy complementary demand response characteristics of multiple loads have further increased uncertainty on the load side.In addition,the integrated energy system has greater energy regulation capabilities due to the use of multi-energy complementary,which have an advantage in participating in multiple energy markets,and effectively bring economic benefits.Based on the steady-state model of the integrated energy system,this paper applied the uncertainty analysis method to construct a robust optimal scheduling model for the integrated energy system.New-energy vehicles are selected as examples of diversified energy needs and the operation of the integrated energy system coupled with the transportation network is considered.The response strategies of integrated energy systems to participate in the energy market have also been analyzed.This article provides a theoretical basis for the safe and economic operation of integrated energy systems.The main research contents and contributions could be summarized as follows:1.According to the energy flow of the integrated energy system,a detailed steady-state model is constructed for each device in the integrated energy system to build a "hub-type" integrated energy system from the energy production,energy transmission,energy conversion,energy utilization,and energy storage,which lays the foundation for the design of optimized dispatching schemes;2.The uncertainty of new energy output and load fluctuation in the integrated energy system is analyzed,and a robust scheduling model for the regional integrated energy system is constructed.A conservative model is applied to analyze the uncertainty of the new energy output.Considering the coupling characteristics between the multiple loads,the Latin Hypercube Sampling method is used to construct the scenario set to analyze the fluctuations of the multiple loads.Considering the day-ahead and realtime scheduling,a two-stage robust optimization scheduling model is established,and CCG iteration and KKT method is applied to solve this model.The studies verify the robustness and economics of the model and its effectiveness in responding to the fluctuation of random variables;3.Based on the analysis of the spatiotemporal uncertainty of the energy use behavior of new energy vehicles,an optimal dispatching model of a multi-network coupled integrated energy system is constructed in conjunction with the transportation network.Aiming at the uncertainty of traffic flow,a data-driven algorithm is used to construct an ambiguity set to form the opportunity constraint.Considering the time cost of the transportation network and the system operation cost comprehensively,the path selection simulation of electric vehicles and natural gas vehicles is used to predict of energy performance.An optimal dispatching scheme that takes into account the uncertainty of traffic flow is formed for a multi-network coupled integrated energy system.The studies demonstrate that the multi-energy coupled system can effectively deal with the energy demand risk caused by the spatial and temporal uncertainty of energy use in traffic flow;4.The behavior of integrated energy system participating in energy market is analyzed,and the integrated demand response model is built.Aiming at the risks of energy price fluctuations in the main energy market and the peak shaving demand that may exist in the ancillary service market,a multi-energy complementary form is used to build a integrated demand response model,and multi-energy complementary evaluation indicators are used to tap the operating potential of the integrated energy system.The studies demonstrate that the multi-energy complementary behavior can effectively suppress the risk of market price fluctuations,and has a large potential for energy regulation.It can achieve a positive interaction with the higher-level power grid and achieve a win-win situation.To sum up,the integrated energy system is an important way to implement the coordination of multiple energy forms and multiple distributed energy equipment.The application of multi-energy complementary behavior for scheduling can effectively reduce the fluctuation risk of source and load-side random variables in the system.Furthermore,by optimizing its own resources,it can interact with the main network and improve the overall economy.Integrate energy system operators can optimize energy scheduling and management based on the actual energy random fluctuations and uncertain response behavior in the integrated energy system according to the models and methods proposed in this paper. |
