Research On Photovoltaic Grid-connected Generation System Based On Fuzzy Control

In the modern society,people are looking for the new efficient energy of low carbon.In thenumerous new energy,Solar energy has many advantages.It is clean,environmental,renewableand wide distribution.Solar photovoltaic power generation can reduce the energy burden of allcountries in the world.Photovoltaic power generation is applied more and more widely andpopularintheworld.There are the off-grid photovoltaic power generation system and the grid-connectedphotovoltaic power generation system.In recent years,the inverter technology and the maximumpower point tracking techenology in the grid-connected photovoltaic system is the focus ofresearch.Using these technologies will greatly enhance the efficiency of energy.This paper willanalyze the5kW single phase photovoltaic grid-connected generation system on the basis oftheoretical study,combined with the content and method have been studied, and comparison of avariety of maximum power point tracking control technology. And the research will focus onthetrackingcontrol technologyofmaximumpowerpoint.Thispaperismainly dividedintoseveral aspects.Firstly, the research status at home and abroad will be summarized,then analysis theadvantages and disadvantages of the application of the method, and determined the mainmethod of this research.And through the comparison of single-stage and multi-stagephotovoltaic grid connected generation system method, the study selected two single-phase PVgridconnected generationsystem.Secondly,the front stage DC/DC circuit and DC/AC circuit after study separately, it canreduce the difficulty of control of each part of the system.Pre-selection of double Boost circuitthat compared with the single Boost circuit, reduces the current ripple and improves the stabilityof the system.Then select the single full bridge inverter circuit.The selected control strategy isthe outer voltage loop and inner current loop.Phase locked loop will achieve unity power factorthroughreal-timevoltageandcurrentofthegrid withthesamephase.In addition,comparison of various maximum power tracking control method, according tothe different advantages and disadvantages, finally use fuzzy control method to achievemaximum power tracking.Based on the fuzzy degree of membership function, the domain ofcomputation,makingfuzzyrules,fuzzy controllerisdesigned. Finally, using MATLAB/Simulink simulation analysis and study on the system ofphotovoltaic cell model, DC/DC circuit model, the inverter model, MPPT model, and gives thesimulation results.Then verify the feasibility of the design scheme of the system, summarize thewholeresearch and makea plan offurtherresearch.