Energy Flow Optimization And Fault Identification Of Integrated Energy System

At present,China's energy development is facing an arduous transition period.Energy Internet is an important strategic direction of China's energy revolution.Integrated energy system is an important physical carrier of energy internet,including electricity,gas,heat(cold)and other energy sources.It can realize the collaborative optimization,interactive response and mutually beneficial operation of heterogeneous energy sources.Based on the analysis of the multi-energy flow characteristics of the integrated energy system,this paper first analyses the interaction characteristics of the integrated energy system under disturbance,and then studies the integrated energy system from the perspective of economic operation and safety and reliability.The specific work is as follows:Firstly,the regional power grid model,the hydraulic and thermal conditions of the regional heat network and the steady and dynamic models of the regional gas network are analyzed.At the same time,typical coupling elements of integrated energy system are analyzed.This provides theoretical support for the multi-energy flow calculation and optimization analysis of the integrated energy system.Thirdly,this paper focuses on the interaction mechanism of integrated energy system,and establishes an integrated energy system model composed of electricity,gas,heat network and coupling elements.A solution framework and method of decomposition method and unified method for multi-energy flow calculation are proposed.Aiming at the problem that multi-energy flow algorithm based on Newton method is sensitive to initial value,an improved unified method based on adaptive step factor is adopted to compare and analyze the accuracy,convergence and convergence time of the three algorithms.Considering the transition process and multi-time scale characteristics after disturbance occurs,the interaction based on quasi-steady multienergy flow is analyzed.Then,in view of the background of large-scale wind abandonment caused by CHP "determining power by heat”" mode in winter in northern China,the multi-energy complementary characteristics of power grid and heat network are fully considered.The thermal decoupling is carried out by using low cost and high efficiency heat storage devices.Considering the network constraints of each sub-network,a coordinated optimal dispatching method for integrated energy system considering wind power absorption and heat storage is proposed.Finally,considering the safe and stable operation requirements of the integrated energy system,this paper takes the energy hub as the coupling part to analyze the interaction between subsystem failures and other energy systems.Firstly,typical characteristic quantities of each energy subsystem are extracted,then heterogeneous feature quantities are fused into high-dimensional space-time matrix in space and time.Then,based on Isomap algorithm,non-linear dimensionality reduction of the matrix is carried out.Then,fault identification and location of integrated energy system are carried out based on local sparse coefficient and node association relationship,which provides a reference for the safe operation of integrated energy system.