| Under the dual pressure of environmental pollution and energy crisis,the utilization of renewable new energy is urgent.With the development of computer technology,control theory and power electronics technology,the utilization of renewable energy has become a reality from theory.In order to better alleviate this dual pressure,"Energy Internet" and "Integrated Energy System",which can not only make full use of a variety of renewable energy,but also realize energy complementarity,have attracted extensive attention once put forward.Then,as the terminal of the two,the "micro energy grid" has become the key of multi-energy utilization research.On this basis,as an autonomous multi energy system,the micro energy grid itself can operate independently from the grid,so in remote areas where centralized power supply is difficult,the micro energy grid running off the grid can be used to provide energy for users.What this thesis does is to propose a scheme of off grid micro energy grid for users in remote areas and study its optimal operation.The specific contents are as follows:Firstly,this thesis summarizes the development and research status of CCHP technology,energy storage technology,micro energy network technology and corresponding technologies on the demand side at home and abroad,puts forward a micro energy network scheme including wind power generation system,photovoltaic power generation system,ground source heat pump system,solar heat pump system and energy storage system,and makes a detailed mathematical modeling of the relevant equipment,At the same time,in order to solve the problem that the energy imbalance of micro energy network affects the safety and reliability of system operation under island operation mode,the concept of demand side response is introduced,the controllable load technology in demand side response is adopted,and the mathematical model of controllable load is established.Then,a micro energy network operation optimization model with economy as the optimization objective is established.The optimization model takes the lowest total operation cost of the system as the objective function,energy balance as the equality constraint,and the upper and lower limits of equipment output as the inequality constraint.The particle swarm optimization algorithm with easy implementation and fast convergence speed is used as the solution method of the optimization model.At the same time,in order to solve the defect that particle swarm optimization algorithm is easy to fall into local optimization,roulette selection algorithm is introduced to improve the optimization mechanism of particle swarm optimization algorithm,and a multi search mechanism particle swarm optimization algorithm based on roulette selection algorithm is proposed.Finally,combined with the typical daily load data of users in this area,according to the meteorological data in summer and winter in this remote area,the output upper limit of wind turbine and photovoltaic generator units on typical days with sufficient scenery in summer and winter is obtained.The particle swarm optimization algorithm before and after improvement is used for optimization calculation,and the optimal operation results of micro energy network in summer and winter are obtained.The results show that the improved algorithm has more reasonable operation arrangement,lower cost and faster convergence speed in the optimization process,which verifies the feasibility and superiority of the improved algorithm. |
