Research On Control Strategy Of Multi-source Microgrid Connection Based On Improved Droop Control

With the increase in the penetration rate of new energy power generation,the elements in the power grid are becoming more and more complex,and large-scale energy storage,charging piles,electric vehicles and other power equipment are gradually appearing.In terms of economic and social benefits,distributed power generation has good results,but compared with the stand-alone access mode,the cost is relatively high.At the same time,the system control is more difficult and requires a wide range of technical adjustments and configurations.,And have an impact on power generation technology.Analyzing the DG control mode,through in-depth research on the control mode of the microgrid in multiple operation modes,it is found that it is difficult to achieve the accuracy of reactive power distribution and other problems.Therefore,this article chooses to analyze the characteristics of multiple power unit access modes.Research on the overall architecture,coordinated control method and scheduling strategy,and propose an improved droop control method to solve the existing shortcomings,and finally realize the grid connection and stable operation of electric energy.This article mainly focuses on the distributed power in the microgrid system,the power on the tie line,and the synchronous grid connection.The main research contents are as follows:First,the working principles of photovoltaic power generation,wind power generation,and storage batteries are analyzed in depth and their influencing factors are considered.Among them,the photovoltaic power generation system is mainly based on the light intensity and temperature,the wind power generation system is mainly based on wind speed,and the energy storage system is mainly based on the external environment.Variety.In addition,a schematic diagram of the equivalent circuit is drawn,and a mathematical model of three independent DGs is established.Secondly,the characteristics of AC,DC,AC and DC microgrids are analyzed,and the common constant power control,constant voltage and constant frequency control and traditional droop control are analyzed separately.The problems and problems in traditional control methods are discussed.insufficient.Regarding the line resistance in the line impedance part,its influence cannot be directly ignored.The active and reactive power of the system exhibit a coupling effect,which will affect the function of droop control.In order to ensure the accuracy of reactive power distribution,when switching between on-grid and off-grid,Corresponding to the addition of virtual impedance,countermeasures to improve droop control are proposed.Finally,modeling and analysis of wind power generation,photovoltaic power generation,and battery storage can be used to establish a micro-grid simulation model in the MATLAB/Simulink software and carry out simulation experiments on the working status of the multi-source micro-grid in grid-connected operation mode.And through comparative analysis to verify the effectiveness of the measures proposed in this article.