The Output Analysis Of Single-phase PV System With Voltage Disturbance

With the exhaustion of the fossil energy increasingly,it is an inevitable tendency that renewable energy will be an irreplaceable part of the energy structure.Photovoltaic(PV)power generation technology has been widespread used in power system and civilian aspects.According to the principle of power generation,the factor of environment changing has become the most significant factor,which influences PV power station steady and high-efficiency running.In this paper,the DC voltage fluctuation of PV power generation system is analyzed under the influence of environment factor,and a kind of definition of voltage disturbance in PV power generation system is pointed out.What we have done is aimed at researching the relationship between voltage disturbance and inverter output of PV power generation system.In this article,the main analysis and studies are listed as below:1.In order to find out the cause of DC voltage fluctuation in PV power generation system,we had made a thorough investigation about PV power generation system in Golmud region to inspect power situation and solar panels fault type.In addition,through the analysis of experimental data and the working principle of solar panels,the cause of voltage fluctuation are obtained finally.The shadow is considered to be the most important reason,which bring about voltage fluctuation in the process of PV power generation system.2.In this paper,a kind of definition of voltage disturbance in PV power generation system is put forward to explain this phenomenon.At first,taking a single piece of panel as the research object,in the shadow experiment,which analysis the relationship between the shadow and the DC output voltage of solar panel.And then,we can get the variation range of DC output voltage of solar panel through the shadow experiment.Compared with the data of PV power generation system,the result shows that the shadow experiment is reasonable and reliable.Finally,the voltage disturbance model is instituted,and the parameters of model are determined.3.The structure of single-phase PV grid system is analyzed.A simulation model,which takes voltage disturbance into account,is set up under the Matlab/Simulink environment.In this paper,the Total Harmonic Distortion(Total Harmonic Distortion,THD)is regarded as measurable indicator.Simulation experiment is carried out under different operating conditions,and then the mathematical relationship between THD and voltage disturbance is worked out through the way of curve fitting.