Research On Influence Of Distributed Photovoltaic Grid Connection On Distribution Network Voltage

The large-scale grid-connected distributed photovoltaic power supply has many effects on the safe and stable operation of the distribution network.The influence on the voltage of the distribution network is one of the main effects.The instability of the output power of photovoltaic power supply connected to the grid is an important cause of deviation and fluctuation of the grid voltage,which poses certain hidden dangers to the safety and stability of the system.As the distributed energy penetration rate increases,the distribution of power flow in the system changes,and the operation and control of the power system also changes greatly.The distributed photovoltaic access distribution network voltage problem is analyzed and the weakening is found.The influence control strategy is of great significance to the development of the photovoltaic industry.This paper first analyzes the working principle and output characteristics of photovoltaic cells.According to the influence of light intensity and temperature on output power,MPPT(Maximum Power Point Tracking,MPPT)technology is used to improve the output efficiency of photovoltaic cells.Based on Matlab/Simulink,the simulation model and photovoltaic power generation of photovoltaic cells are established.The net model analyzes the specific effects of light intensity and temperature on output power,and sets the specific parameters of photovoltaic cells and distribution networks.Then,from the perspective of influencing the voltage deviation and voltage fluctuation,the voltage characteristics of the traditional passive power distribution network and the voltage distribution characteristics of the distributed photovoltaic power grid after the grid are analyzed.According to the different access locations,different access capacities and different inverter power factors of distributed photovoltaic power sources,the different effects of voltage deviation of distribution network are studied.Comparing single-supply radiating distribution network and having simple ring network structure.The different influence mechanisms of voltage fluctuations in the distribution network and verification by simulation show that the ring network structure can effectively improve voltage fluctuations.In this paper,by analyzing the traditional PV(Photovoltaic,PV)reactive voltage dispersion autonomous control strategy,a PV reactive voltage dispersion autonomous control strategy for reducing voltage disturbance is proposed.Based on the improved PV reactive voltage regional autonomous control method,the method is triggered.Based on the local control strategy,local decentralized autonomy control is realized by utilizing local control information.At the same time,based on Matlab/Simulink,the reactive power-free voltage control strategy,the traditional fixed-parameter control strategy,and the improved PV reactive voltage regional autonomous control strategy distributed distribution network model are established respectively.The rationality and effectiveness of the proposed strategy are verified by simulation.