Research On Planning Of Integrated Energy System Considering CCHP

Integrated energy system(IES)refers to the energy integration system formed by the optimization of energy production,transmission,distribution,conversion,consumption,and storage in the process of planning,design,construction,and operation.IES can realize energy cascade utilization through organic coordination and optimal dispatch of various energy systems,which can significantly improve the security,flexibility,economy and reliability of energy supply.Combined cooling heating and power system(CCHP)has developed rapidly in recent years due to its flexibility of system scheduling.The research on planning of integrated energy system considering CCHP was studied in this thesis.The main contributions are as follows:A planning model based on mixed integer linear programming(MILP)of integrated energy system considering CCHP is established.Multi-stage planning and multi-scenario analysis are adopted.CCHP system is used as coupling hub to connect power and natural gas energy systems.The network topology of the distribution network,the network topology of the gas network and the location and capacity of the CCHP system are considered in the model.In the aspect of model solving algorithm,this thesis introduces cutting plane method,branch and bound method and Branch&cut method combined with them.The model adopts Branch&cut method at last.This method has both advantages in algorithm structure.For the equipment mathematical model of integrated energy system,this thesis establishes a detailed mathematical model of integrated energy system including gas turbine,gas boiler,heat recovery system,absorption refrigeration system and electric air conditioning.Secondly,for the mathematical model of integrated energy system planning,this thesis establishes the objective function with the lowest total investment and operation cost as the optimization objective,and four constraints including electricity,gas,cold and heat load balancing,as well as the constraints of CCHP system construction and operation.For simulation of integrated energy system planning,two examples are set up in this thesis,that is,integrated energy system considering CCHP and traditional energy distribution system.Yalmip toolbox in MATLAB is used to model and Gurobi optimizer is used to solve the model.The result of selecting the equipment of the system and the total investment of the system are obtained.Cost analysis shows that the integrated energy system considering CCHP has better economic performance.At the same time,the relationship of the electricity purchased from superior power grid and the gas purchased from superior gas network with electricity price and natural gas price is emphatically analyzed.The integrated energy system model proposed in this thesis can solve the optimization problem of multi-energy supply joint planning,and correspond to the latest reform in the national energy system.It is hoped that the research findings of this thesis can provide theoretical method and support for IES planning and Energy Internet development.