Research On Optimization And Benefit Evaluation Of Integrated Gas-electricity Energy System Participated With P2G

The energy supply and consumption model based on coal and other fossil energy highlights the energy and environmental problems caused by a single energy structure.At the same time,with global warming,increased air pollution,and deterioration of the living environment,the urgency of energy supply and consumption reforms has become more prominent.In recent years,the development and utilization of integrated energy systems have been advancing rapidly,and the subsequent development of power to gas(P2G)technology has promoted the flexibility of the integrated electricity-gas energy system scheduling operation It provides a new way for the intermittent power generation of wind power,photovoltaic and other renewable energy sources,and also lays the direction for the research of this paper.The operation optimization of the integrated gas-electricity energy system participated with P2G technology and evaluation of its comprehensive benefits will be a key research problem.The specific research contents are as follows:Firstly,this paper sorts out the relevant theories of the integrated gas-electricity energy system,clarifies the basic components and functions of the system,and compares the differences between gas and electricity systems;This paper systematically sorts out the basic theory of P2G technology and considered the uncertainty of wind power output,considering the uncertainty of wind power output,and introducing the conditional value at risk(CVaR)to further quantify the risk of wind curtailment and the reserve cost of system capacity;Finally,this paper analyzes the internal and external benefits of integrated gas-electricity energy system,effectively defines the main content of the system’s economic,environmental and social benefits,and laies the theoretical foundation for subsequent research.Secondly,a multi-objective collaborative optimization operation model of P2G participation in the integrated gas-electricity energy system under uncertain wind power is constructed.Based on the P2G carbon capture effect,gas-electricity coupling effect,low capacity reserve cost and other functional characteristics,this paper designs four optimization goals,including system operation cost,wind power consumption rate of gas system,total carbon emission reduction and capacity reserve cost.Based on electricity system,natural gas system,thermal energy system and coupling elements,the constraints of the model are clear:Secondly,in order to reduce the possibility of the optimal solution falling into local optimality,the mixed integer linear programming conversion is realized by the linear conversion method.The Sigmoid function is used as the fuzzy membership degree function.which provides method support for subsequent chapters.Thirdly,a 10-node power system and a 6-node natural gas system are selected as simulation examples,and various scenarios are set.The results of the example show that after the P2G equipment is participated,it can optimize the overall system,and reduce the wind curtailment rate,realize the "peak cutting and valley filling" of the electric load.It can increase the carbon emission reduction benefits and reduce the cost of spare capacity,etc.,Meanwhile it can improve the overall benefit of the system;Through sensitivity analysis,changes in parameters such as wind power penetration and P2G capacity configuration will cause changes of the operating status and operating results.Finally,by adjusting the confidence level of wind power output,the nonlinear relationship between the confidence level and the system operating target is fitted.The fitting results indicate that wind power output uncertainty level will indirectly affect the system optimal scheduling results,which proves the necessity of studying the multi-objective collaborative optimization operation model of the integrated gas-electricity energy system under uncertain wind power output conditions.Finally,the comprehensive benefit evaluation model of integrated gas-electricity energy system is constructed.Along with the planning,supply,equipment operation,power distribution,and end users,the integrated gas-electricity energy system comprehensive benefit evaluation index system is designed.Through the combination of subjective and objective index weighting methods,the weight of each index is clarified.The ideal solution ranking model is improved by using the matter-element extension idea,and the comprehensive benefit evaluation model of the integrated gas-electricity energy system is established.Compared with other energy systems,P2G equipment participates in scheduling and provides capacity backup for the integrated gas-electricity energy system owns best comprehensive benefit evaluation result,which provides a reference for the optimization of integrated gas-electricity energy system and related industry development.