Cooperative Planning Of Gas-electric Interconnection System With Power To Gas Stations

Natural gas system and power system are two major energy systems on which people rely.Natural gas can be easily converted to thermal energy firstly and converted to electrical energy afterward through nature gas fuel plants.Electrical energy is the most convenient secondary energy for converting into other forms of energy.At present,the rapid development of power to gas(PtG)technology is driving the two energy systems to be coupled organically through nature gas fuel plant and power to gas plant station.This has opened up a new way for the comprehensive utilization of energy through the two major energy systems of natural gas and electricity.Under the condition of meeting the demand of natural gas load and electric load,how to rationally plan the gas-electric interconnection system is a complex problem involving engineering system technology and economic technology.Therefore,it is important to carry out the research on the planning of gas-electric interconnection system considering PtG stations.A multi-objective planning model for gas-electric interconnected system with PtG stations is constructed.Taking the expansion of power lines,natural gas pipelines and the site selection of PtG stations as the center,a three-object mixed integer nonlinear planning model for gas-electric interconnected systems is constructed based on the PtG principle and the steady state characteristics of natural gas system.On the premise of satisfying the user's electrical load and natural gas load demand,the goal of the proposed model is to maximize net profit of the three entities of electric power systems,natural gas systems,and PtG stations respectively.In the model,the connectivity of the whole gas-electric interconnection system is ensured by accessing natural gas pipelines or power lines to the PtG sites.A method for solving multi-objective planning model for gas-electric interconnected system based on bargaining game is proposed.The power system,natural gas system,and PtG stations are considered as three game players.The essence of the bargaining game is that participants reach agreement after multiple bargaining,and an equilibrium solution is obtained by which each party cannot obtain greater profit by changing the strategy.A solution method for gas-electric interconnection system planning model based on a bargaining game is given combing the essence of the bargaining game.By solving the Nash bargaining solution function,the Nash bargaining solution is obtained,and the model is solved.This method is compared and analyzed with other multi-objective solutions.A capacity expansion planning method for different types of PtG stations based on cooperative and non-cooperative games is proposed.The PtG stations are considered as coalition participants(the number is n).In the whole cooperation and non-cooperative game modes which are composed of 2~n-1 alliances,a capacity expansion planning model for each PtG stations is established.The objective function is to maximize the net profit of different types of PtG stations.The PtG stations capacity expansion planning model is considered as a"Cournot model".The traditional"Cournot model"iteratively searching method is used to solve the cooperative and non-cooperative game modes,and the capacity planning results of different types of PtG stations under the best coalition combination are obtained.The above method is simulated and analyzed based on the AMPL simulation platform.The simulation example uses a modified Belgium20 node natural gas system and a modified IEEE-RTS24 node power system.The results show that the planning scheme obtained through the bargaining game can obtain better total economic benefits than the separate planning of the power system and the natural gas system under the traditional model,and more solid expansion scheme could be obtained than the implementation of the centralized collaborative expansion.For the PtG stations capacity expansion planning problem,each participant forming coalitions to play a cooperative game can obtain more benefits than play a non-cooperative game,but the participant's profit in the coalition is not positively correlated with the size of the coalition.