Modeling And Analysis Of Integrated Energy System And Its Operation Optimization

With the rapid development of economy and technology,the demand for energy in human society has risen sharply.Countries around the world are trying to explore a new way to optimize the overall distribution of all kinds of energy to achieve sustainable development.Integrated energy system(IES)has come into people's sight.IES effectively realizes the rational distribution of energy flow and improves the efficiency of energy utilization through energy complementarity among energy sub-networks such as heating network,power network and gas supply network.It will undoubtedly become the future direction of energy development.In order to accurately simulate the overall performance of integrated energy system and carry out it's relating planning and operation optimization,and system economic evaluation services,It is necessary to unify the modeling and analysis methods of energy sub-networks in the integrated energy system.In this paper,based on the theory of energy network,we reveal the general characteristics of different types of energy flow in space and later we describe the inertia,elasticity and dissipation of energy in space by resistive elements,elastic elements and inertial elements.Sooner we construct the transmission element model and the energy coupling element model in the integrated energy system according to the bond graph theory.On this basis,the time-varying/time-invariant network equivalent model of integrated energy system is established.In order to investigate the operational characteristics of integrated energy system,the time-varying/time-invariant energy network equation of integrated energy system is constructed to study the steady/dynamic characteristics of integrated energy system under different operating conditions.Subsequently,the concept of “exergy” is proposed to characterize the energy quality of the system.Aiming at minimizing the economic exergy loss of the system,the optimization model of regional integrated energy system operation is established considering the two modes of heating and cooling of the system.The genetic algorithm with elite retention strategy is used to optimize the proposed models in order to obtain a better operation strategy for the current period.On this basis,combined with the approximate dynamic programming method,the day-ahead scheduling decision-making of integrated energy system is optimized to improve the overall economic efficiency of integrated energy system in multi-period.