Research On Optimal Configuration And Economic Operation Of DC Microgrid

With the rapid growth of DC power supply load ratio,DC microgrid has become an important means to deal with high penetration distributed energy and multi-load access with its advantages of low cost,low loss and high controllability.With the reform of energy policy and the development of electricity market,microgrid will bear its own profit and loss in the future market competition.How to rationally allocate microgrid and improve operation efficiency has become one of the most concerned problems for operators.However,China’s micro-grid operation is lack of mature operation mode and reasonable way of investment return,and renewable energy subsidies have become a final decision,the economy of the system will be difficult to be guaranteed.Based on this,the optimal configuration and economic operation of DC microgrid are studied.The main research contents are as follows:1.On the basis of analyzing the typical structure of DC microgrid,the mathematical models of micro-power units such as wind power system,photovoltaic system,energy storage system and grid-connected converter are established,and the basic principles of optimal configuration and economic operation of DC microgrid are expounded.2.In view of the development trend of green trading system replacing financial subsidies,this paper analyzes the current situation of green trading system in China,puts forward three modes of DC microgrid participating in green trading market,analyzes the market price mechanism and establishes a single market profit model.Secondly,considering the system investment and maintenance costs,electrical energy benefits and green transaction benefits,and taking the maximum annual return of the system as the optimization objective,the K-means clustering method is used to simplify the scene,and the improved fast particle swarm algorithm is used to solve the system optimization configuration model,so as to improve the computational efficiency.In addition,in order to flexibly respond to the demand of load power supply and renewable energy consumption,a comprehensive energy management strategy is proposed to optimize the output logic of each unit.Finally,the influence of green trading system and energy management strategy on the configuration results is analyzed and compared with the HOMER simulation results.The example results verify the effectiveness of the proposed method.3.Based on the background of China’s new round of power system reform,this paper constructs the ’source-network-load-storage’ integrated operation mode under the power market environment,analyzes the economy of microgrid under traditional operation mode and market operation mode,and establishes the optimal scheduling model under different operation modes.In order to effectively tap the potential of user response and improve the revenue of operators,the distributed generation,energy storage and adjustable load are aggregated into virtual power plants,and the adjustable load response mechanism based on price incentive is proposed.The master-slave game model is constructed with the goal of maximizing the benefits of operators and users,and the decision-making model of lower users is transformed into a constraint condition,which is solved by the Yalmip and Cplex toolbox.Finally,by comparing the results of the five groups of operation schemes,the economic benefits and units output under different operation modes are investigated,the influence of peak shaving auxiliary service market mechanism on renewable energy consumption is analyzed,and the effectiveness of the optimal pricing strategy is verified.