Modeling And Analysis Of Multi-energy Complementary System Based On Energy Network Theory

Energy internet not only realizes the sharing between energy producers and consumers,but also realize interconnection and sharing between different forms of energy.Multi-energy complementarity is the basic component of energy Internet,the common multi-energy complementary system are distributed energy supply system and integrated energy system.There is a lack of theoretical guidance for multi-energy complementary system,so it is urgent to propose a modeling and analysis method for complex multi-domain coupling system.This paper summarizes the literatures of multi-energy complementarity,energy science and system dynamics at home and abroad,and points out that energy is the bridge between the different types of energy and physical processes.Aiming at the modeling and analysis of complex multi-domain coupling system,this paper studies from the following four aspects: 1)Based on the energy network theory,the distributed energy supply system is modeled and analyzed,and the correctness and practicability of the energy network theory are verified;2)Exploring the generalized transfer law of exergy in lines(pipes)and establishing the transfer analysis theory of exergy in lines(pipes);3)Extending the existing energy network theory and establishing the energy network equation of integrated energy system,and further constructing a optimization model of integrated energy system based on genetic algorithm;4)Establishing the time-varying energy network theory,and proposing a method of modeling and simulating the dynamic characteristics of the multi-energy complementary system by constructing time-varying energy network equations(including state equations and output equations).The specific work of this paper is as follows:Firstly,the theoretical basis of energy network theory is introduced in detail,and the generalized transfer equation of energy in lines(pipes)is obtained through rigorous mathematical derivation,then the energy transfer process and exergy transfer process are discussed in depth.The research contents of this chapter lay the foundation for the following chapters.Secondly,a distributed energy supply system is modeled and analyzed based on the energy network theory.The comparison between the calculated data and the actual operation data verifies the correctness and practicability of the energy network theory.Compared with the energy transfer analysis,the energy loss caused by the transfer irreversibility is taken into account in the exergy transfer analysis.Based on the exergy transfer theory,the generalized law of exergy transfer in lines(pipes)is obtained through theoretical analysis and derivation.Thirdly,based on the generalized Kirchhoff's law and specific characteristics of branches of different forms of energy in lines(pipes),the energy network equation of integrated energy system is established.Taking the minimum energy loss as the goal,combining with the equality and inequality constraints of system,an optimization model of integrated energy system based on genetic algorithm is constructed.Finally,compared with time-invariant network,the transfer process of time-varying energy network will appear some new laws and characteristics.On the basis of the in-depth nature of energy,the time-varying energy network theory is established,and a method of modeling and simulating the dynamic characteristics of the multi-energy complementary system by constructing time-varying energy network equations(including state equations and output equations)is proposed.