Research And Design Of Microgrid Control Method Based On Inverter Control

With the increasing dependence of the society on energy,the traditional fossil energy is decreasing with the application of human production and living.Distributed energy will be the best choice for energy substitution in the future.However,due to the output power of distributed energy is instability,the power system architecture of large power grid can not accept this generation method friendly.The wide application of energy storage devices has changed the way of grid connection of distributed energy sources.At the same time,the concept of micro-grid system has also developed.The micro-grid system composed of micro-power device,energy storage device,inverter and power load.It can be connected with the large grid system,and also can be isolated from the large grid system.In order to ensure the stability of the micro-grid system,a reliable control method is needed in the process of micro-grid system changing the operating conditions.Firstly,this paper study the basic knowledge of micro-grid,including the concept of micro-grid,research and application as well as the main components of micro-grid,such as solar photovoltaic power generation,energy storage devices and inverter units.Given a circuit topology of the three-phase voltage source inverter,and deduced its mathematical model in the dq rotating coordinate system.Secondly,classified the common energy storage devices in the current market,and compared the working principles and characteristics of different energy storage devices.Study the functions of energy storage devices in different operating modes of micro-grid system.Thirdly,Because of the photovoltaic cells are widely used in production and living,this paper build a model and simulation of photovoltaic cells.Analyzed the important role of maximum power point tracking technology in solar photovoltaic power generation system.Then,disscuss the traditional inverter control methods such as constant PQ control,V/f control and droop control..Finally,aiming at the different control modes of the inverter in the distributed generation system,proposed a multi-loop control method of the micro-power,and designed a simulation module of the controller in the MATLAB/Simulink simulation software.Verified the reliability and stability of the control method by simulating the different situations that the micro-power inverter may encounter in practical application.In summary,this paper builds a micro-grid system model in MATLAB/Simulink simulation software.Through the design of inverter control circuit,the stability of electrical parameters in the micro-grid system under different operating conditions is realized,thus ensuring the reliable operation of the micro-grid system,which is of great help to the development of micro-grid system.