Research On Photovoltaic Grid-connected Power System

Photovoltaic grid-connected power generation is the major development trend in the useof photovoltaic solar, therefore the photovoltaic power generation technology has become ahotspot in the world, and it is bound to be a rapid development. In this paper, based on acomplete photovoltaic grid-connected system as the study object, focuses on two key part ofthe three-phase photovoltaic grid-connected power systems, photovoltaic grid-connectedinverter control and photovoltaic power generation maximum power point tracking carried outresearch.Firstly, introducing the significance of solar photovoltaic power generation, thedevelopment status at home and abroad as well as its broad prospects for development, themain research contents of this topic are given.Secondly, the paper briefly introduces the composition and classification of solarphotovoltaic power generation system. Comparative analysis of several kinds of circuittopology, and ultimately determine to use of the two stages photovoltaic grid-connectedinverter structure as the research object.In addition, describes the working principle of three-phase photovoltaic grid-connectedinverter, and control target of photovoltaic grid-connected inverter. By analyzing andcomparing several more grid-connected inverter current control strategy, this paper uses thespace vector pulse width modulation (SVPWM) current output control method, and make ananalysis on the SVPWM control algorithm, the mathematical model was established, and thespecific design of the parameters of the model, through digital simulation softwareMATLAB/SIM-ULINK to build a model of the control system of photovoltaic grid-connectedinverter and simulation experiments. The validity of this method is verified by simulationresults.Finally, given the equivalent circuit of solar photovoltaic cells, the analysis of the outputcharacteristics of the solar cell, mathematical model is established, and the modeling andsimulation of output characteristics of the any solar irradiance and ambient temperature.Analysis and comparison of several maximum power point tracking method, the realization ofMPPT control based on the incremental conductance method Boost converter, the simulationexperiment on the digital simulation software under the MATLAB/SIMULINK environment,the simulation result shows, when the irradiance and the solar energy battery temperature change, the maximum power point incremental conductance method can photovoltaiccomponent tracking.