Research On Maximum Power Point Tracking Control Based On Asymmetric Fuzzy Logic Control Of PV Power System

At present, people in the world are beset with big problems of energy shortage and environmental pollution. So seeking clean and renewable energy which can replace traditional energy is imperative. PV powered system are used widely more and more because of its advantage of clean and non-polluting. However, the solar cells are expensive, its photoelectric conversion efficiency is low, and its output characteristics are easily and seriously affected by environmental factors. So it is necessary to research maximum power point tracking controller to enhance the utilization of solar cells, and this is important in the practical application.The article focuses on researching a maximum power point tracking controller based on an arithmetic of asymmetric fuzzy logic control. Simulation analysis has proved the feasibility of the method. At the same time, comparing with an improved disturbance observation method further proves the superiority of the method.First, the background and significance of this thesis are summarized. At the same time, the main research content is also depicted. Then begin with expounding the working principle and derivating the mathematical model of engineering of solar cells, the simulation model based on Matlab software is established, so that simulating and analysising of its output characteristics are done to verify the practicality of the model. On this basis, the basic principles of maximum power point tracking is introduced. After comparing and analysising several maximum power point tracking algorithms which is in common use, the summary of their advantages and disadvantages is given. Because it is difficult to determine the voltage step of the disturbance observation, this thesis introduces an improved disturbance observation. Then according to the non-linear and asymmetric of the output characteristics of the PV cells, the arithmetic of asymmetric fuzzy logic control is introduced, and the thesis focuses on designing an asymmetric fuzzy logic controller which is suitable for the system. Based on analysising the common used DC/DC chopper circuits, the Boost converter is determined to be used as the main circuit topology of the maximum power point tracking system, then analysises the operating principle of the Boost converter and designs its main parameters, the simulation verifies the correctness of the design. Finally, based on the above work, the maximum power point tracking system model based on Matlab is builded, the simulation analysis proves the feasibility of the the maximum power point tracking system based on asymmetric fuzzy logic control, and the fact that compares with the improved disturbance observation method shows the superiority of the method.