The Leader-follower Game Theory Strategy And Multi-Objective Operation Optimization Of The Integrated Energy Systems

Nowadays,with the depletion of fossil energy and the increasing environmental pollution,the global demand for improving the efficiency of energy management and the need of achieving sustainable development of energy and the environment is even more urgent.The comprehensive utilization of various energies such as electricity,natural gas,thermal energy and renewable energies can be realized by integrated energy system.The integrated energy system that integrates the production methods of multiple energies has been widely applied in recent years for its advantages of high efficiency and low energy consumption.With respect to the optimal operation of transmission network,the increase in the proportion of gas-fired power plants in power generation bring the result that the coupling between natural gas networks and power grids has become increasingly close.The optimal operation of integrated electricity and natural gas networks has been actively discussed by scholars.However,only considering economic indicators can no longer meet the urgent need for energy saving and emission reduction nowadays.For multiple-objective optimization problems,especially with multiple objectives in conflicting relationships,the single-objective approach is no longer applicable.In addition,integrated energy systems also consist of distributed energy stations(DES)that produce a number of energies including cold energy,heating,and electricity to satisfy the demands of energy users(EU).For example,in an industrial area,distributed energy stations and users need to make a contract for multiple energies transactions.In the open energy market in the future,they will pursue their individual interest during the interaction.In the face of a complex and comprehensive energy system in the future,how the participants formulate optimal strategies on the interaction of multiple energies to maximize their own profit is also a hot topic of research today.This paper focuses on the two aspects of the integrated energy system and carries out research related to the multi-objective optimization and game theory methods.In terms of the optimal operation of integrated electricity and natural gas networks,this paper considers both economic and environmental performance,and adopts a multi-objective group search optimizer and evidential reasoning decision method to solve this problem.Gasfired power plants provide linkage between electricity and natural gas networks.The model of natural gas network consisting of gas sources,loads,pipelines and compressors is calculated by the Newton-Raphson method.The fuel cost and pollutant emission of the integrated electricity and natural gas system are considered as objective functions.Afterwards,a multi-objective group search optimizer is used to solve the operation problem of the optimal power and gas flow of the integrated electricity and natural gas networks and get the Pareto-optimal frontier.Furthermore,a decision making method based on the evidential reasoning(ER)is utilized to determine a final optimal solution from the Pareto-optimal frontier.The proposed method will provide suggestion for the optimal operation of the integrated electricity and natural gas networks.In terms of the optimal interaction strategies for multiple energy between multiple distributed energy stations and energy users in an integrated energy system,this paper proposes an analytical model of multi-leader multi-follower Stackelberg game in order to explore the interactions between the two parties.The hierarchical Stackelberg game model considers the benefits of both DES and EU,and enables EU to make demand responses to maximize their welfare.In this model,the DES lead the game by independently deciding the amount of natural gas input for generation of both the electricity and heating energies and jointly setting the energy prices to maximize their own profit.While the EU,play as followers and determine the energy demands based on the prices the DES announced.We show that the leaders game follows a supermodular game,which finally reaches a unique Nash Equilibrium(NE).Moreover,We derive the closed-form expression of the Stachkelberg Equilibrium of the game between DES and EU.The exsistence and uniqueness of the SE are also proved.Furthermore,a distributed algorithm is proposed to obtain the SE of this game with limited information.Numerical studies demonstrate the validity of the proposed game scheme as well as the efficiency of the distributed algorithm.The proposed game model will provide advice to the development of transaction contracts between DES and EU.