Research On Active Power Control And Power Prediction Of Photovoltaic Power Plants

As the demand for global energy continues to grow,the contradiction between the development and utilization of fossil energy and environmental protection has become increasingly fierce.The excessive use of fossil energy,such as coal,will directly lead to the emission of large amounts of carbon dioxide into the atmosphere,resulting in an environment such as greenhouse effect.Changes,and the smoke produced at the same time will pollute the global atmosphere,so the consumption of traditional fossil energy will eventually lead to serious environmental pollution and ecological deterioration.With environmental pollution and the depletion of fossil fuels,photovoltaic research has attracted worldwide attention.The development and utilization of green energy is imminent.Solar energy is a kind of renewable clean energy,with abundant resources,small environmental impact,and good prospects for development and utilization.It has become one of the major development directions of clean new energy in China.Photovoltaic power generation is a way to convert solar energy into electrical energy,but it cannot be avoided accompanied by instability and other characteristics.With the increasing installed capacity of photovoltaic power generation,the proportion of electricity in the national power grid is increasing rapidly,and the inevitable will be for the power grid.Stability and security pose a threat.In view of the above problems,this paper mainly studies the basic principles of photovoltaic power generation prediction and power control system,and combines the practical application of photovoltaic power generation prediction and the research of photovoltaic power generation control system based on virtual synchronous machine to explain this more comprehensively.The content of the graduation thesis.Firstly,the power characteristics analysis of photovoltaic power generation is introduced,including factors such as radiation intensity,temperature,season and weather type.Then the general composition of photovoltaic grid-connected power generation system is introduced,and the topology of several common grid-connected inverter systems is carried out.The analysis and comparison,and the analysis and comparison of the four control modes and the combined control mode,and then the operation process and basic principle of the power control are explained according to the two-layer active power control structure.Secondly,the structure,system control principle and ontology modeling and simulation implementation of virtual synchronous generator photovoltaic grid-connected system are introduced.Then the relationship between active power balance and system frequency in power system and the relationship between reactive power balance and system voltage are analyzed.Furthermore,the principle and design method of VSG power frequency controller and excitation controller are proposed.Finally,the simulation results are built to analyze the relevant results.Thirdly,the theoretical knowledge of neural network is introduced,and the neural network library provided by Matlab platform is used for modeling research.Finally,the overall architecture of the power prediction system is illustrated,including the system network structure and system function structure.Then,the main functional modules of the system are introduced in detail through actual project cases,and the practical application of the optical power prediction system is clearly demonstrated.