| Energy is the international hot issues nowadays, it is the basis of economic development and fundamental guarantee of people’s happiness life. Our country with a large population and shortage of energy, we has been looking for new clean and renewable energy sources to replace traditional non-renewable energy sustainable development. The solar energy is a kind of clean and renewable energy, and that the way to the energy transformation in the future is necessary. The solar energy was used in the photovoltaic electric generation field mainly.Photovoltaic power generation system is the use of photovoltaic effect of the photovoltaic panels to convert solar energy into electrical energy, and supply to the load After by Power conversion. Since photovoltaic cells were the key to the photovoltaic power generation system, the photovoltaic cells existed the problem the high cost and low conversion efficiency at present. In order to improve the efficiency of the photovoltaic cells, the output of photovoltaic cell needs to be controlled in order to output the most power of it. Therefore, researching on maximum power point tracking of photovoltaic cell has important practical value in photovoltaic power generation system.Firstly, this paper introduced Photovoltaic power generation dynamic home and abroad. Then the prospect of China’s photovoltaic power generation was pointed out. It concluded that photovoltaic power generation was the inevitable choice of our country to take the road of sustainable development. This paper overviewed the principle of the photovoltaic power generation system, and analyzed the working principle and output characteristics of photovoltaic cell. Photovoltaic engineering models were established in MATLAB software for simulation studies. Because the output characteristics of photovoltaic cell is nonlinear, the output power of battery will change when it’s output voltage changes. The output voltage of PV cells needs to be controlled. For photovoltaic maximum power point tracking issues, a variety of experimental method for photovoltaic maximum power tracking was summarized and analyzed. This paper selected fix step admittance incremental method and variable step admittance incremental method for maximum power tracking. The programs to implement both methods were write in MATLAB by s-function. Simulation results demonstrated that the two algorithms can trace to the photovoltaic maximum power point, the variable step-size mobility by incremental step is not only in dynamic performance but also on the steady performance has significantly improved in maximum power tracking. The Boost-based maximum power point tracking system was set up, the simulation results showed that the parameters of Boost circuit were selected reasonable and the output voltage was stability when PV output maximum power.Secondly, on the basis of MATLAB software simulation, photovoltaic maximum power point tracking (MPPT) hardware platform was set up. The main circuit based on Boost and controlled circuit and detection circuit were built. Then a variety of protection of IGBT buffer circuits was introduced. The RCD snubber circuit as a protection circuit for IGBT was selected in this paper. The experiment results showed that RCD snubber circuit was effectively inhibited switch tube turn-off over-voltage.Finally, the TMS320F2812of TI company of USA was taken as the controller. The maximum power point tracking procedures was programmed in the CCS environment. Combined with the hardware circuit, maximum power tracking of photovoltaic cells were achieved, and the final result proved programs correctly effectively and stability. |
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