Research On Photovoltaic Grid Of The Influence In The Low Voltage Distribution Network And Reactive Power Optimization

With the accelerated development of global economy,energy depletion and environmental pollution problems are becoming increasingly prominent,the scientific research of various countries in the field of energy has turned to renewable energy which Photovoltaic is a typical representative.The application of PV is mainly to connect in the medium and low voltage distribution network,which makes the traditional radial distribution network to turned into a multi-power active distribution network and changes the characteristics of power flow and voltage.The unreasonable access of photovoltaic will cause out-of-limit voltage limit,voltage fluctuations,harmonic pollution and other problems.Therefore,it is necessary to fundamentally analyze and study the impact of photovoltaic grid distribution on the distribution network,and carry out reactive power optimization research in distribution network ingerated with Photovoltaics to solve the problems caused by photovoltaic connection.Based on the above,this paper is entitled with study on the impacts of grid-connected photovoltaic and reactive power optimization in medium and low voltage distribution network.The main research contents of this article are as follews:(1)analyse the influence of grid-connected photovoltaic on power flow,voltage distribution,line current and network loss,from the mechanism,and study the influence on voltage distribution and network loss of the installed capacity,girid-connected position and the inverter power factor by simulations;(2)analyse thereactive power and voltage control method in distribution network with photovoltaics,the mathematics model and working principle of centralized reactive power optimization,and introduce the algorithms of reactive power optimization;(3)adding the method of photovoltaic inverter power factor regulation to traditional reactive power optimization,the static/dynamic integrated reactive power optimization in distribution network with photovoltaics is constructed,and the simulations based on Donguan Yinfeng feeder in Guangdong Grid is taken to verify the validity of the proposed model,where suggest that the method of photovoltaic inverter power factor regulation is conducive to optimize the system power flow and reduce active power loss.