Research On Maximum Power Point Tracking Control Techniques Of Solar Photovoltaic

With the current world energy crisis and the increasingly serious problem of environmental pollution, how to solve the contradiction between energy and the environment and achieve sustainable development has been paid more and more attention. Solar energy as a new energy, its reserves are rich and renewable, clean and no environmental pollution, what’s more, there is no problem of energy shortage, so it has become the focus of the current research. However, the output of solar photovoltaic cells is nonlinear and the environmental factors have very large effect.Therefore, in order to improve the efficiency of photovoltaic power generation, the research of maximum power point tracking control of photovoltaic is very important.Firstly, beginning from the most basic photovoltaic cells, this paper introduced the working principle and working characteristics of photovoltaic cells. According to the equivalent circuit of the photovoltaic cells, in the environment of MATLAB/ Simulink we established the engineering simulation model of the photovoltaic cells. We got the photovoltaic I-V and P-V curve with simulation, and verified the accuracy of the model.Through the analysis of the output characteristics of photovoltaic cells under different environmental conditions, we summarized the change rules of the maximum power point.Then this paper introduced the principle of maximum power point tracking,compared several common maximum power point tracking method. In view of the advantages and disadvantages of each method,we designed two kinds of improved algorithm-- fuzzy control strategy and adaptive P&O algorithm, and in Matlab/Simulink algorithm module were built respectively. Through the simulation, it showed that the proposed algorithms had better dynamic and steady state characteristics.Finally,this paper assimilated and analyzed the working principle of several commonly used DC-DC converters in photovoltaic power generation system. On the basis oftheoretical analysis, we designed the maximum power point tracking controller. The controller used Buck-Boost converter as the main circuit, which can boost and buck with a wide range of voltage. Using Altium Design software to draw the hardware circuit diagram, and the analog acquisition module, PWM driver module, LCD module and remote communication module have been designed. According to the proposed adaptive disturbance control algorithm, using Keil software complete the corresponding controlling codes. The design of remote monitoring software was completed by using Qt Creator software on the remote host computer.In this paper, the design process of photovoltaic cells simulation model and algorithm in Matlab environment was introduced in detail; at the same time, the design process of MPPT controller hardware circuit and software program were introduced.The designed controller could not only display the running state of the photovoltaic system locally, but also monitor in the remote computer.