Research And Design Of Photovoltaic Array Simulator

With the power level of photovoltaic power generation improves continually, the research and development work of photovoltaic power generation system has become more and more important. Experimenting with the photovoltaic cell array simulator instead of real photovoltaic cells can greatly shorten the development period, reduce development costs, increase efficiency of research and the creditability of results. Therefore, photovoltaic battery array simulator has become an important development direction in the field of photovoltaic power generation system research.According to the equivalent circuit of photovoltaic array, the working principle and output characteristics of photovoltaic array are analyzed in detail, the engineering mathematics model for photovoltaic array is setted up, and the photovoltaic cells simulations have been completed in MATLAB respectively. In this thesis, an experiment platform of the photovoltaic cell simulator was designed based on the BUCK main circuit topology and TMS320F2812 DSP control chip. Meanwhile,through anatomizing and contrasting several traditional simulator algorithms commonly, a new kind of intelligent fuzzy control algorithm used in photovoltaic array simulator system is devised to overcome the deficiencies of traditional control algorithms. The algorithm real-time acquisition BUCK converter output voltage and used to calculate the current of photovoltaic array engineering mathematics model which is used as the input reference current of fuzzy controller. The difference of the reference current and the real-time feedback current of Buck converter and its rate of change are regarded as two input variables of the fuzzy controller, and then the duty cycle of the electronic power switch is adjusted by closed-loop fuzzy algorithm to make the output voltage and current of the simulator to work at the anticipant point of the photovoltaic array on the V-I characteristic curve and realize the simulation of photovoltaic properties. Fuzzy controller with TMS320F2812 CPU and triangular fuzzy membership function is used and the domain of the input and output variables limited to [-3 3], contains 49 fuzzy rules.In order to verify the effectiveness of the fuzzy control algorithm, this paper established MATLAB simulation circuit and experiment platform of the photovoltaic cell simulator. Simulative and experimental results have shown that the fuzzy control simulator not only can accurately simulates the static output characteristics of photovoltaic cell, but also can rapidly realizes the dynamic characteristics well when the load or the external environment changes,and It's comprehensive performance compared to traditional simulator algorithm have greatly improved.