Study On The Impact Of Photovoltaic Power Supply On Wuzhong Power Grid

With the development of society and economy,on the one hand,human demand for electricity is increasing day by day,on the other hand,it has caused serious environmental pollution.The development of photovoltaic power generation can be a good solution to the above two problems.Wuzhong City,Ningxia Province,can make full use of solar energy because of its geographical advantages,and can transmit abundant electricity to the eastern region of large quantity of electricity.However,due to the instability of PV output and the access of PV power to the grid,a series of unstable factors will be brought to the power grid,which may have an impact on the stable operation of the power grid.This paper mainly discusses the influence of photovoltaic power supply to Wuzhong substation.First of all,this paper introduces the research results at home and abroad and the current research status of grid connected photovoltaic power stations.This paper analyzes the key technologies of grid connected photovoltaic power generation,establishes the mathematical model of photovoltaic panels and the mathematical models and equations of photovoltaic power grid connection,introduces the basic principles of photovoltaic generation,analyzes the factors that influence the output of photovoltaic cells and the process of grid connected photovoltaic power generation.According to the results of the new energy flow calculation in Luoshan in Wuzhong City,the influence of the PV power supply system on the power flow and voltage of the system is expounded.Secondly,the power quality of the system and the change of transformer relay protection are analyzed after the PV power is connected to the grid.The effects of voltage,voltage fluctuation,flicker and frequency harmonic wave on the power grid are analyzed respectively.The size of PV power and the different voltage level of access substation,the fault occurs in the incoming line and the non incoming line of the system,and the short-circuit current supplied by PV power to the fault point is different.The operation of distance protection in Wuzhong substation is analyzed and the corresponding measures are put forward.Finally,statistics on the situation of load utilization,new energy power station and development plan in Wuzhong City in 2016 are given,and the installed capacity of new energy access to different locations is detailed.For example people voted chrysanthemum Taiwan photovoltaic power station access Wuzhong grid are analyzed,based on grid PV power plant access system design principle,system voltage level selection and access point selection is that the grid connected photovoltaic power station can access line carry stone 110 kV substation,line on 10 kV 524 stone chrysanthemum Taiwan line of this two schemes,technical comparison two different photovoltaic power station access system,select the most suitable scheme.According to the 10 kV and 110 kV bus Ningxia Taiyangshan grid connected photovoltaic power plant connected to the Luoshan 330 kV substation,using photovoltaic power station access substation electromagnetic transient simulation software PSCAD/EMTDC 15 MWp and 30 MWp capacity,analysis in the inlet and outlet line of three-phase fault between short-circuit current and photovoltaic side point fault of each branch flow system and the system side voltage comparison.The bus maintenance mode and new energy access situation of Luoshan substation in Wuzhong City are analyzed,and the solutions are put forward.