PV系统变电压MPPT算法及其仿真研究

一种高效的最大功率跟踪方法对于提高光伏发电系统的输出效率是非常重要的。常用的恒定电压跟踪算法在快速跟踪最大功率点的过程中存在跟踪效率差、精度低和适应性差等问题。经过理论分析与仿真研究，发现同一块太阳能电池在相同的温度和照度，不同的二极管反向饱和电流Io和品质因子n的情况下，输出的光生电流是相等的。结合爬山法得到实际的n和Io后，爬山法就不需要了。本文构建的跟踪最大输出功率的新颖的变电压MPPT控制算法可与天气状况相匹配，快速找到最大功率近似点，而通过综合补偿，可以准确跟踪到实际的最大功率点。最后，结合变化的天气情况，验证了该算法的正确性与有效性。

Study on Solar Energy Photovoltaic System Variable Voltage MPPT Control Algorithms and Simulation

In order to efficient extract the maximum output power from a photovoltaic (PV) system it is important to have an efficient Maximum Power Point Tracker (MPPT). The conventional Constant Voltage Tracking (CVT) method have some problems in that it is impossible to quickly acquire the generation power at the maximum power point, i.e., the efficiency and the precision of electric power generation is very low, and the adaptability is very bad under different meteorological condition. It is found theoretically and simulation that a piece of solar cell have same photocurrent in different diode factor and reverse saturation current at same temperature and irradiation. This paper describes a new combined perturb and observe (PO) method for acquire the actual diode factor n and reverse saturation current Io. The PO method will be stopped when the actual n and Io have been acquired. A novel MPPT algorithm can tracked the maximum power point by the compensate parameters corresponding to weather conditions at that time. Correctness and validity of algorithms is verified by simulation results under different irradiation and temperature conditions.