Optimization Of Micro-grid Economic Operation Based On Energy Storage Nuit

The unified coordination and management of the distributed power supply by the microgrid solves the technical problem of accessing the distribution network of renewable/clean energy such as wind/light.The microgrid adopts the electric energy production mode in which the distributed power generation is absorbed locally,which reduces the power transmission loss and improves the reliability of the power supply.Therefore,economic dispatching of the operation of the microgrid for the upgrading of the competitiveness and promoting the construction of the microgrid are of great significance This paper focuses on the battery charge and discharge management and the application of heat storage unit in the cogeneration system.The improved genetic algorithm is used to study the economic operation of the microgrid.The main contents are as follows:1)The solution process of genetic algorithm is studied.The reason why the genetic algorithm has local convergence in the optimization process is analyzed,and the genetic algorithm is improved.The algorithm uses an elite retention strategy and a dual adaptive mutation operator based on iterative steps and population fitness.In order to verify the performance of the improved algorithm,the improved algorithm was tested by a more complex test function.The simulation results show that the improved algorithm has good global search performance under different population sizes.2)For the charge and discharge management of the battery with multi-stage coupling characteristics,the discharge stage evaluation index based on real-time electricity price and load shortage is proposed.The battery is charged and discharged based on the remaining capacity.Taking the minimum operating cost of the microgrid as the goal,the improved genetic algorithm was used to simulate the case.The simulation results verify that the proposed charge and discharge management strategy has good economics for the overall operation of the microgrid.3)In view of the current lack of flexibility in cogeneration operation of microgrid,a model for economic dispatch of cogeneration microgrid with wind power,photovoltaic,micro gas turbine,fuel cell,battery and thermal storage unit is proposed.The model aims at minimizing fuel costs and operating and maintenance costs.Based on the real-time electricity price of the distribution network,considering the residual heat storage capacity,heat load,electrical load and the output of each micro-source,different operational control strategies are proposed.Finally,a specific example is used to analyze and compare the economics and flexibility of adding a thermal storage unit and the traditional ordering power by heat operating mode.The simulation results show that the addition of heat storage unit can break the rigid coupling constraint of ordering power by heat and make the operation more flexible and economical.