The Influence Of Distributed Photovoltaic Power Grid On Power Quality

Since the industrial revolution of mankind,with the consumption of fossil resources,the living environment has been deteriorating day by day.Comparing with the traditional centralized power supply and distribution,photovoltaic power generation has a short construction period and a small investment.However,large-scale grid-connection has a greater impact on the power quality of the grid system.Therefore,it is necessary to study the effect of photovoltaic power grid-connection on the power quality of the system.First of all,the working principle and main features of the photovoltaic power generation system are expounded,the components and main functions of the distributed photovoltaic power generation system are briefly introduced,and the technical requirements of grid connection and the influence on system voltage and harmonics are introduced.Secondly,Matlab/Simulink platform was used to build the main component models of photovoltaic cells,dc voltage conversion circuit,inverter,filter and other photovoltaic power generation systems,study the maximum power point of photovoltaic cells and inverter control strategy,and establish the control circuit.Through the simulation analysis on the radiation intensity and environment temperature changes,photovoltaic(pv)power output current,voltage and power nonlinear relationship between the inverter controlled by current hysteresis comparison in different power output voltage and current harmonic change,determine the inverter as far as possible under the conditions of rated power running,the basic function of the phase-locked loop to determine the structures of distributed photovoltaic power precision of the model.Finally,using the Matlab/Simulink platform building practical distribution network model of Texas area before it is distributed and photovoltaic(pv)power grid access to distribution network model,a simulation model simulation analysis access change location and capacity,and the main distribution network node voltage distribution and the harmonic distortion rate,determine the distributed grid-connected photovoltaic(pv)effect on the grid power quality,and power quality evaluation method and corresponding improvement measures are put forward.