Analysis Of Distributed Photovoltaic Power Grid Connection And The Influence On Distribution Network

With the development of productivity,energy consumption and environmental pollution have become increasingly serious.The world urgently needs a non-polluting,renewable energy source to replace traditional fossil energy.Distributed photovoltaic power supply has attracted worldwide attention due to its many advantages such as its green environmental protection and renewable energy.This article mainly studies and analyzes the effect of grid-connected distributed photovoltaic power supply and its connection to the distribution network,and takes the Zhangbei 20 MWp photovoltaic power generation project as an example for analysis and research.Firstly,this paper expounds the principle of photovoltaic power generation from the mathematical model of photovoltaic cells,and analyzes several major problems that restrict the rapid development of distributed photovoltaic power generation.Then PSCAD simulation modeling was used to simulate the process of photovoltaic power generation.The simulation waveform was also consistent with the theory.The maximum power point tracking control is then designed using the conventional conductance increment method to achieve maximum power tracking at different lighting and ambient temperatures.Two types of grid-connected principles and methods of distributed photovoltaic power supply were studied and analyzed.Then,Zhangbei 20 MWp photovoltaic grid application example was studied and analysed.Firstly,the solar energy resources in Zhangbei County,Zhangjiakou,Hebei Province were analyzed.Then the overall design and power generation were calculated,including the selection of PV modules,the selection of peak power of solar modules,the selection of PV array operation modes,and the selection o f inverters,PV array design and on-grid electricity calculation.Finally,the design of the electrical main wiring was carried out,including the first and second parts.Finally,the influence of the distributed photovoltaic power supply after grid-connection on the power quality,relay protection,network loss,grid reliability,and power grid planning of the distribution network is studied in detail.The impact on power quality and network loss is described in terms of both positive and negative aspects.Finally,it is concluded that the difference in distributed photovoltaic power supply capacity and access location will have various degrees of impact on the distribution network.