Research On Economic Operation Optimization Of Regional Multi-Microgrid With CCHP

The combined heat and power(CCHP)system is a distributed energy source,which has the comprehensive benefits of energy saving,environmental protection,and flexible power supply.The CCHP system can improve energy efficiency through energy cascade utilization.Natural gas is usually used as the main fuel to drive micro gas turbines,and waste heat recovery systems are used to recover waste heat for power generation,and to supply heat or refrigeration according to demand.With the development of distributed energy,the fluctuation of new energy and the problem of consumption have become serious problems restricting its development.The emergence of microgrids has provided a flexible operating platform for distributed CCHP systems,which has improved the rate of wind energy consumption and efficiency.The economic operation of microgrid is an important content of microgrid operation management.This thesis focuses on the optimization of economic operation of microgrid with CCHP.The specific research content is as follows:First,the thesis establishes the mathematical model of cchp microgrid and multimicronet systems,and gives the system structure of single micronet and multimicronet,which lays the foundation for economic scheduling optimization of cchp microgrid and multimicronet Secondly,the thesis proposes an economic optimal dispatching model for CCHP microgrids under the conditions of time-of-use electricity prices and grid connection.The objective is to minimize the operating costs of microgrids during the scheduling period.According to the operating conditions of the microgrid,a cost-minimizing operation strategy was proposed,and the model was solved using an improved firefly algorithm to obtain the optimal output of the equipment in the microgrid and the total operating cost of the microgrid.Through the comparison of simulations,it can be concluded that the cost-minimized operation strategy is significantly better than the traditional heat-based and electricity-based heating strategies.Compared with the solution results of the standard firefly algorithm,the simulation results show that the improved firefly algorithm has faster convergence speed and higher optimization accuracy.Finally,the thesis establishes an optimal scheduling model for a regional multi-microgrid system with different types of micro-grids.Multiple micro-grids connected to the power distribution network belong to the same decision maker.These micro-grids can trade electricity with each other.Then a multi-behaved particle swarm algorithm is proposed to solve the model,and the advantages of the multi-behaved particle swarm algorithm in optimization accuracy and convergence speed are verified through several common test functions.The thesis analyzes the typical daily load in a certain area and compares the difference between the internal microsource output and the difference between the total operating costs of the multi-microgrid under the coordinated and independent operation modes of the multi-microgrid.The simulation results show that considering the energy exchange between microgrids can effectively reduce the total operating cost of the multi-microgrid,thereby verifying the effectiveness and economics of the multi-microgrid economic scheduling model proposed in this thesis.In summary,this thesis has carried out a series of studies on the optimal dispatching of microgrids with CCHP,summarized the economic scheduling issues of cchp microgrids and multi-microgrids,and looked forward to the future.