Research On Distributed Photovoltaic DC Power Supply And Control Of Grid Connected Inverter

Now,with the increasing fossil energy,deterioration of ecoiogical environment,haze around the grave,development and utilization of new energy gradually into people's vision,get everyone's attention.Wherein the clean,environmentally friendlyn ew energy photoelectric be actively developed.photovoltaic power generationg radually expand the scale,showed a rising trend,solar energy as a clean green e nergy,so it is very important and necessary for us to research the key of technologies,This paper focuses on the study of distributed photovoltaic DC power supply and the control of grid inverter.A brief introduction to the photovoltaic cell works and classification;Detailed analysis of the different external conditions of the photovoltaic cell I-V and P-V characteristic curve;Analysis of several conventional Maximum Power Point Tracking algorithm,this selection of incremental conductance and the impact analysis of temperature,light intensity changes in the output power generated by the PV system.Simple analysis of the grid-inverter configuration,and network requirements,the main circuit,Several common current tracking methods are described,On this basis,the paper puts forward the compensation method of power network voltage feed forward,and for the four control modes are built four simulation models.Finally,the results of the experiment are summarized.the power grid voltage feed forward compensation control mode based on PLL technology is the best and low harmonic content,excellent dynamic performance;At last,the detection of the isolated island effect is introduced,It focuses on the active islanding detection method for Auto Frequency Drift(AFD)method,and the periodic perturbation method used in this paper.As well to the principle of the method to do a brief analysis,build a simulation model in Matlab to do experiment.