Research On Maximum-Power-Point-Tracking Control Method Of Photovoltaic Generation System

Now, Energy crisis is increasingly serious, looking for an alternative energy has become the forcus of research. As the unusual advantages of abundant, renewable, clean, etc, solar energy is accepted commonly, and the development of solar energy has been unprecedented attention. Photovoltaic (PV) power generation is the direct use of solar energy. But the outut of PV cells is influenced by the environmental factors, and the efficiency of PV system will be affected. To solve this problem, this paper focuses on Maximum-Power-Point-Tracking (MPPT) control of PV system, analyses the theory particularly, estanblishs simulation model with MATLAB software, and validated by experimental results.Firstly, this paper analyses the part of PV system, classified the PV system based on the different occasions, and introduces the application of ssPVsystem.at home and abroad.Secondly, this article establishes the simulation model of PV cells from analysing the working principle and characteristic curves of PV cells, and analyses commonly used MPPT methods, such as CVT method, P&O method, INC method and fixed-parameter method, etc. On the basis, this paper put forward the improve method:Constant-current combined with Perturbation and Observation, and analyses the control process and the flow chart.Thirdly, the paper comparatively analyses the principle of two commonly used DC-DC converters, and make use of the Boost circuit to establish the converter in PV system. In the text, the analysis and design of parameter of Boost circuit is given. Then establishes the PV system control simulation model, and achieve the simulation experiment use P&O method, INC method and Constant-current combined with Perturbation and Observation method. The experimental resulsts show that the effect is better.At last, the paper explores the inverter of the grid-connected PV system. For the wide use of the single-stage grid-connected PV system, the article gives the control principle and creat the simulation model, then carry out simulation in the MATLAB environment.