Research On Optimization Strategy Of Community-level Integrated Energy System In Carbon-neutral Background

"Carbon peak,carbon neutral" has become the core power of China’s future economic development,but it also puts forward new requirements for the current energy structure optimization.According to this plan,China will gradually reduce the utilization rate of fossil energy in the 14 th Five-Year Plan,increase the proportion of electric energy used in terminal side,and increase the installed capacity of green energy sources such as wind power and photovoltaic.In order to achieve the goal of carbon neutral,the state grid will be more diversified.Based on the background of carbon neutral,this paper focuses on the decarbonization of community-level integrated energy systems,including the access of green energy sources such as wind power,photovoltaic and so on,the input of heat storage equipment,the cascade utilization of integrated energy systems,low-carbon green buildings and other related aspects,which are summarized as follows:Firstly,the concept of typical community-level integrated energy system is expounded.Basis on this,the main components of energy supply equipment model,auxiliary energy supply equipment model,energy storage equipment model and so on are analyzed.By introducing the concept of thermal inertia of buildings,a mathematical model of building temperature considering thermal inertia is putted forward,which provides model support and theoretical basis for the next stage of community level integrated energy system optimization strategy research.Secondly,the optimization model of community-level system considering the characteristics of new energy output is studied.On the basis of the Latin hypercube sampling method,the sampling results of the Latin hypercube sampling method for large-scale sampling arrays are analyzed.On the other hand,based on the typical integrated energy equipment mathematical model,using the energy bus balance,considering the operation constraints of each integrated energy equipment,energy storage equipment,maximum and minimum force constraints,the community level integrated energy system is modeled and analyzed mathematically.In addition,a two-layer optimization algorithm of community-level integrated energy system considering the thermal comfort of users is proposed and built.The lower layer optimization function is quadratic,the Lagrange method is used to transform the KKT condition of the upper layer function,and the original double layer optimization problem is changed into the MPEC problem of the upper layer function form.The dual variables in the MPEC are eliminated to make the original problem become the MILP problem.The upper objective function is the maximum profit of the regional energy dealer,and the lower layer takes the minimum value of the heating cost penalty function considering the thermal comfort of the user as the optimization goal.The lower layer optimization target obeys the upper layer optimization goal,achieves the community level integrated energy system optimal scheduling under the two-level goal.Finally,based on the two optimization methods proposed in this paper,a residential area under Changzhou Power Grid in Jiangsu Province is designed and implemented respectively.On the one hand,aiming at the optimization model of community-level integrated energy system considering the characteristics of green energy output,taking the minimum daily comprehensive energy cost of integrated energy system connected by energy storage equipment as the optimization goal,The daily operation results are obtained by using 0-1 mixed integer linear programming method;On the other hand,according to the proposed two-layer optimization model of community-level integrated energy system considering user comfort analysis,the two-layer problem is transformed into MPEC problem by two-layer optimization KKT conditions,and the MPEC problem is transformed into MILP problem by BMM method.The results are obtained by using the CPLEX solution software.The results show that compared with the original operating cost,the community-level integrated energy system optimization model proposed in this paper has significant economy considering the characteristics of green energy output.At the same time,the two-layer optimization model of community-level integrated energy system considering user comfort analysis is more economical and lower heating cost than the traditional thermal inertia optimization algorithm.The reliability is higher and can satisfy the maximum comfort of the user at the same time.