Research On Planning Of Bi-direction Coupling Integrated Electricity And Natural Gas System Based On Power-to-gas Technology

With the continuous development of social economy and energy technology,energy efficiency and environmental friendliness have gradually been valued by people.The integrated energy system is not only able to handle different types of energy conversion,but also to accept a considerable amount of clean energy,which is one of the current energy development trends.A typical type of integrated energy system is integrated electricity and natural gas energy system,which is coupled by power system and natural gas system.The integrated electricity and natural gas system with gas turbines and power-to-gas devices is a bi-direction coupling integrated electricity and natural gas system.Compared with the traditional one-way coupling integrated electricity and natural gas system with only gas turbines,it has the ability of both gas to power and power to gas.Based on this,this paper takes the bi-direction coupling integrated electricity and natural gas system as the research object,aiming at its planning problem.The main research results of this paper are as follows:Firstly,a bi-direction coupling integrated electricity and natural gas system model is established.The basic structure of integrated electricity and natural gas system including the energy flow path and the energy conversion mode is designed,and the model is built based on this.Then the necessary components of power network is analyzed,and the power network model including power flow,thermal power generating unit and topology structure is established.Next,the necessary components of natural gas network is analyzed,and the natural gas network model including gas flow,compressor and topology is established.After that,the energy conversion equipment in the bi-direction coupling integrated electricity and natural gas system is analyzed,and a gas-electric coupling device model including gas turbine and power-to-gas device is established.Secondly,aiming at the one-way coupling integrated electricity and natural gas system of existing gas turbines,a planning method for site selection of power-to-gas devices is proposed.Based on the established bi-direction coupling integrated electricity and natural gas system model,the objective function aiming at economy is set,and the relevant constraints are written on the premise of the safe operation of each subsystem in the coupling system,some of which are linearized.Then the Gurobi solver is used to solve the optimal construction time and location of the power-to-gas device in an example,which verified the feasibility of the proposed method.Next,the values of power load and natural gas load are changed to observe impacts on planning results.The results show that the planning method can solve the installation location and installation time of the power-to-gas device well,which can provide reference for the one-way integrated electricity and natural gas system that needs to construct the power-to-gas device in the actual project.Finally,a joint planning method is proposed for the one-way coupling integrated electricity and natural gas system with other facilities expansion requirements in addition to power-to-gas devices.Based on the established bi-direction coupling integrated electricity and natural gas system model,the objective function with multiple planning objects is set,and the constraints are rewritten and linearized.Then a new example is constructed.The Gurobi solver is used to solve the optimal construction time,optimal construction location and optimal construction capacity of thermal power generating units,gas turbines,power lines,natural gas pipelines and power-to-gas devices.Next,the price of natural gas,electrovalence and the efficiency of gas turbines are changed separately to observe their impacts on planning results.The results show that the method is suitable for solving such problems and has guiding significance for the initial construction and price estimation of actual projects.