Research On Distributed Photovoltaic Access Scheme With Power Quality Optimization

The large scale of distributed photovoltaics has been integrated into the distribution network,which has made outstanding contributions to alleviating environmental conflicts and power supply pressures.But it also has many adverse effects on the power quality of the grid.As the proportion of distributed photovoltaics in the distribution network increases further.This will inevitably aggravate the adverse effects it brings,and even threaten the safe operation of the power system in severe cases.Therefore,it is necessary to analyze the impact of distributed photovoltaic grid-connected power grid on power quality of distribution network,and comprehensive evaluation of distributed photovoltaic power generation system and access scheme.This paper first introduces the basic working principle and technical points of each part of the distributed photovoltaic power generation system.The grid-connected model of photovoltaic cells and distributed photovoltaic power generation systems was built by Matlab/Simulink simulation software.The article briefly describes the main application scenarios of distributed photovoltaics in China and their scene characteristics.Then introduce the current international,national,organizational and company standards related to power quality.The relevant standards of China’s distribution network power quality fluctuation caused by distributed photovoltaic grid connection are sorted out,and the measurement methods and limit regulations are briefly introduced.Then the article makes a theoretical analysis of the key indicators of power quality that are mainly affected by distributed PV grids such as voltage deviation,voltage fluctuation and harmonics.Then use the above simulation model to carry out simulation analysis to verify the theoretical derivation,and the comprehensive research results illustrate the impact of photovoltaic grid-connected on various power quality indicators.This paper establishes a new method for power quality assessment based on data envelopment analysis.The feasibility of data envelopment analysis in the field of power quality assessment is verified by comparison with other proven traditional power quality assessment methods.Finally,a comprehensive evaluation method is constructed,which takes photovoltaic parameters,energy storage configuration and power quality optimization device as input,and uses power quality related evaluation indicators as output.This method is extremely inclusive for input and output,and can comprehensively consider distributed photovoltaic grid-connected power generation systems.Rather than blindly pursuing the grading assessment of power quality,it has practical guiding significance for distributed photovoltaic access distribution networks.Through this method,the influence of subjective factors can be avoided to the greatest extent,and the distributed photovoltaic access scheme can be comprehensively evaluated scientifically and objectively.Finally,a comprehensive evaluation of multiple actual photovoltaic grid-connected projects is carried out through two different models,and the optimal grid-connected scheme is selected.At the end of the paper,the distributed PV planning recommendations are given by combining the evaluation results and impact analysis.