Research On Control Strategy Of Multi-Energy Microgrid

With the development of the world economy,energy and environmental issues have begun to emerge one after another.In order to deal with these problems and realize the sustainable development of energy,replacing traditional fossil energy with new energy has become the focus of attention and research of various countries.The application of distributed microgrid can effectively reduce the environmental protection problems caused by the utilization of natural resources,and fully meet the requirements of all aspects.This paper proposes a reasonable coordinated control strategy for the operation and regulation of distributed AC microgrid.The thesis first outlines the basic structure of the microgrid,introduces the basic principles of photovoltaic power generation,wind power,diesel power generation and other equipment in the microgrid system,and establishes a mathematical model based on the working characteristics.The importance of arranging storage battery equipment is analyzed,and a mathematical model is established for battery charging and discharging characteristics.Secondly,for the purpose of improving the efficiency of new energy,the output of new energy sources is achieved by comparing the maximum power tracking strategy.As wind power systems,the improved variable-step perturbation observation method is used to track the maximum power.For photovoltaic power generation systems,this paper studies the use of fuzzy perturbation observation method to track the maximum power;the additional battery energy storage system supports the bus voltage frequency in the microgrid,The effect of suppressing power fluctuations in the network,so the state of charge control strategy is applied to it,and the feasibility of the above strategy is verified through simulation.Then,it analyzes the inverter,which is an important part of control implementation.The inverter can perform a variety of controls on the micro power output.Choose different micro power control strategies according to the different situations of the micro grid in the grid-connected/off-grid mode.When connected to the grid,the micro power supply needs to reflect the stable output of the power,so PQ control is adopted.When the system is off the grid,the system must be adjusted for constant voltage.Therefore,it is necessary to specify the module to adopt the V/f control strategy,and the master-slave control strategy is adopted for the entire system.By the way,the control strategy of the energy storage system has been improved,and the MPC algorithm is adopted to enable the system to predict the changes of the busbar more accurately and improve the response ability of the system.Finally,build a complete simulation model in the simulation software.The control strategy is specified for grid-connected operation,and the simulation study is carried out for two situations with and without energy storage;three common situations are proposed for isolated grid operation,and the control strategy is specified and simulated one by one.The analysis of power,voltage,and frequency verifies the stable operation and the rationality of the control strategy.