分段自适应变步长最大功率跟踪法

Segmented adaptive variable step size maximum power tracking method

光伏组件始终工作在最大功率点(MPP)处是提升光伏系统中能量转化效率最有效的方法。传统的扰动观测法(P&O)具有算法简洁、跟踪效率高的特点,但常常无法兼顾最大功率跟踪速度和稳态精度,并且传统的扰动观测法还存在着当环境突然变化时因跟踪点漂移而发生误判的现象。为此提出了一种分段自适应变步长扰动观测法。在MPP周围以2%P(max)区间为分界将跟踪区域划为三部分,根据距离MPP的远近及位置选用三种不同的跟踪步长进行扰动跟踪,并且在初始跟踪时根据光强的强弱设置了相应的基础占空比,达到了快速跟踪的效果,并在一定程度上有效阻止了因环境突变跟踪点发生误判的问题。经仿真验证该算法能够达到设计效果,在性能上优于传统P&O算法。

Photovoltaic modules working at the maximum power point(MPP)is the most effective way to improve the efficiency of energy conversion in photovoltaic systems.The traditional perturbation observation method(P&O)has the characteristics of simple algorithm and high tracking efficiency,but often cannot balance the maximum power tracking speed and steady-state accuracy.This method also leads to the misjudgment due to the drift of the tracking point when the environment suddenly changes.Based on these shortcomings,this paper proposed a simple piecewise adaptive variable step size perturbation observation method.The tracking area was divided into three parts with a 2%Pmax interval around the maximum power point,and different tracking steps were selected for disturbance tracking according to the range from the maximum power point.The initial tracking was set according to the intensity of the light intensity.The corresponding initial duty ratio achieved the effect of fast tracking,and effectively prevented the shortcomings of misjudgment due to sudden changes in environmental tracking points to a certain extent.