Flexible Optimal Configuration Of Electric Thermal Integrated Energy System

With the development of the world economy,human demand for energy is also deepening,followed by environmental pollution and energy crisis and other issues also plagued the pace of human development.People’s desire to seek clean,green and sustainable energy is deepening,which promotes the rapid development of new energy.But at the same time,the access of new energy represented by wind power will bring changes to the operation mode of the system,and the traditional resources in the system can not meet the demand for flexibility.Especially in the northern region with abundant wind resources,the output mode of combined heat and power(CHP)in winter heating period is mainly thermal output,which makes the system lack of flexible adjustment ability.When the demand for flexibility of wind power is large,it seriously affects the stable operation of the system,so it is necessary to abandon the wind.In order to solve the problem of insufficient flexibility in wind curtailment and absorption,it is necessary to add new flexibility resources,change the traditional energy supply mode and seek a new flexibility balance.Through the reasonable use of flexible resources such as CHP unit,electric boiler,heat pump and heat storage tank,the electric thermal integrated energy system can establish the connection and mutual influence between electricity and heat,give play to the complementary characteristics between electricity and heat,make use of the advantages of electric transmission and heat storage,improve the system flexibility adjustment ability,and provide enough space for the use of wind power.In order to give full play to the role of flexible resources in meeting the demand of flexibility,it is of great significance to study the flexible allocation of electric thermal integrated energy for improving the flexibility and energy utilization of the system.This paper first analyzes the output characteristics of wind power,starting from the energy supply structure and characteristics of electric thermal integrated energy system,studies the operation principle of flexible resources such as CHP unit,electric boiler,heat pump and heat storage tank,and establishes the corresponding model,which provides a theoretical basis for the subsequent flexible optimal allocation of electric thermal integrated energy system.Secondly,the flexible optimal allocation of the electric thermal integrated energy system involves the planning and operation of the system,and the operation efficiency of the electric thermal integrated energy system largely depends on the optimal allocation of flexible resources,and the allocation of flexible resources has different effects on the wind curtailment and absorption of the system.Considering the interaction between system planning and actual operation to ensure the flexibility of the system,the concept of double-layer optimization model is introduced,and a double-layer optimization configuration model of electric thermal integrated energy system is established,in which the upper planning layer takes the lowest annual comprehensive cost as the goal and the lower operation layer takes the lowest annual operation cost as the goal.Based on the bi-level optimization problem,genetic algorithm and fmincon function are used to solve it in MATLAB.Finally,taking an electric thermal integrated energy system in northern China as the research object,considering the wind power output in winter heating period,combined with the data of typical power,heat load and wind power in winter,the optimal configuration results and wind power consumption effect under different configuration schemes are analyzed,and the optimal flexibility of the electric thermal integrated energy system is obtained by comparing the annual comprehensive cost of different configuration schemes The configuration results are simplified.The analysis shows that the electric boiler has the best effect on wind curtailment,and the heat pump can save the fuel cost.At the same time,the electric thermal integrated energy system with electric boiler and heat pump has advantages in economy and wind curtailment effect.