Research On The Optimal Configuration And Operation For CCHP Microgrid

Facing the problems of serious environmental pollution and energy shortage, the changing of the traditional power generation mode and the use of renewable energy and clean energy become an important step in the national energy strategy. With multiple advantages including high energy utilization, flexible control, high power supply reliability, the combined cooling and heating power(CCHP) micro-grid gradually becomes the focus of global research. Multi-system with the CCHP equipment is usually close to the user side to make full use of local natural resources and reduce the consumption of fossil fuels. As well, the system can be built in the area without public power grid coverage, to solve the difficulties that the remote areas face. In this paper, a study of optimal configuration and operation of CCHP is carried out, whose core parts are gas turbines, double effect absorption chillers and batteries. The main work of this paper is shown as followed.First, the development situation of the CCHP micro-grid in the domestic and overseas is analyzed, and the mathematical models of gas turbine, wind turbine, photovoltaic, fuel cell and battery are established. Cost function of unit capacity of gas turbine, varying function which shows the power generation efficiency and thermal efficiency change with the load ratio are introduced. The energy conversion characteristic function of the battery model is introduced, to coordinate the ratio of the cooling part and the heating part with the gas turbine. The double effect absorption chiller is taken as the core equipment, and the energy conversion function is given.Then, the three operating modes of the CCHP system are introduced, and the application fields and the advantages and disadvantages of different operation modes are analyzed. At the same time, three performance evaluation indexes of the multi system are given. According to the proposed indexes, the energy saving, environmental protection and economy objective functions are set up, respectively.Finally, a study of optimal configuration and operation of the CCHP multi-system is carried out with the objective of economy. Chaos particle swarm optimization algorithm is utilized to solve the model, and the three configuration schemes are obtained. It is known that the batteries are helpful in reducing the operating cost of the system and adjusting the balance of the heat and cold through comprehensive comparison of the three schemes. The influence of natural gas price fluctuation and electricity price change on the capacity of the system is discussed in this paper. Based on the demand of cold, heat and electricity in typical days of three seasons, the output of the system under different operation modes is obtained by simulation. The results are used to coordinate the output of the power system, and the real-time price is introduced to allow the power flow between the micro-grid and the main grid, which can improve the economy of power system. And analysis of the battery in the role of stabilizing the load is made in this paper.The scheme in this paper provides suggestions for the optimization of the configuration and operation of the CCHP micro-grid system, improves energy efficiency, enhances the consumption ability of renewable energy in the micro-grid and provides solutions to the difficulties in electricity use that people in remote areas face.