基于光伏功率等效面积法的多峰最大功率追踪控制方法

摘要

当光伏组串受到不均匀照射时,其输出特性将会从原来的单峰曲线变成有多个峰值点的多峰曲线,因此受到非均匀照射的光伏阵列含有多个局部峰值点(Local Maximum Power Point,LMPP),使用常规的最大功率跟踪控制方法很难准确的追踪到全局最大功率点(Global Maximum Power Point,GMPP).针对上述问题,首先基于MATLAB仿真软件搭建了光伏组串在受到非均一阴影遮挡情况下的模型;其次研究了其功率-电压(P-U)特性和导数(dP/dU-U)特性,分析了全局最大功率点与光伏功率等效面积之间的关系;最后提出了基于光伏功率等效面积所决定的工作区间定位的新型多峰最大功率点追踪(Maximum Power Point Trace,MPPT)控制方法.仿真结果表明,所提出的光伏功率等效面积法算法能够有效且快速的寻找到全局最大功率点.%When the PV string is under non-uniform illumination, its output characteristics will be changed from the original single peak curve into a plurality of peak values of multi peak curve.Therefore, the non uniform irradiation of the PV array containing a plurality of local peak point (local maximum power point, LMPP), using conventional max-imum power tracking control method is difficult to accurately track the global maximum power point ( global maximum power point, GMPP) .To solve this problem, firstly, a model under the non uniform shade of the PV string is built based on the MATLAB simulation software.Secondly, we study the characteristics of the ( P-U) power-voltage and ( dP/dU-U) derivative characteristics, and analyze the relationship between the global maximum power point and photovoltaic power equivalent area.Finally, a new multi-peak MPPT control method is proposed which is based on the working range decided by photovoltaic power equivalent area.Simulation results show that the proposed method can effectively and quickly find the global maximum power point.