Research On Low-Power Photovoltaic System And Maximum Power Point Tracking

Nowadays, the world's energy shortage and environmental pollution problem are becoming increasingly serious, So the renewable and clean energy development has been gaining attention. The technology of photovoltaic(PV) conversion is developing quickly, which is an effective way to use solar power. In order to maximize the use of solar energy, this thesis focuses on the PV power generation systems, which includes modeling of PV systems, maximum power point tracking(MPPT) methods for PV arrays.First, The output characteristics and mathematecal model of the PV cells are introduced.Its practical engineering simulation model in the Matlab/simulink environment is established. After the simulation verification, the model can replace the PV cells in the theoretical simulation study.Secondly, MPPT theory and various MPPT algorithms are introduced in the literature. Furthermore, this article analyzes the principle of buck circuit and impedance transformation characteristic in stand-alone PV system with MPPT technology applications. The simulation study of buck circuit applied in the MPPT is completed based on Simulink simulation model.Finally, the hardware circuit is built. From date of PV array under different installed angle, there is a lot of work has been done during main circuit and peripheral circuits designed, including choice of PV array, parameter's design of Buck circuit, control circuit, drive circuit and detection circuit. The energy storage device of stand-alone PV system, battery's charge circuit are designed. The charge current and MPPT are analyzed at the same time by single chip MSP430F149, the stability of PV system is achieved.