考虑阴影影响的光伏阵列仿真算法研究

Study on Simulation Algorithm of PV Array Considering Shade Effect

针对光伏发电输出功率的波动性和随机性,为了改善光伏发电功率的可预测性和最大功率跟踪的准确性,必须深入研究阴影对光伏阵列输出特性的影响。首先以光伏组件为基本单元,兼顾旁路二极管和防逆二极管的影响,建立光伏阵列的高维数学模型,提出了易于分布式实现的、适用于任意阴影条件的光伏阵列输出特性快速计算机仿真算法。不同阴影条件下的仿真结果表明,光伏阵列的输出特性与阴影的分布范围及其光照强度密切相关,阴影使光伏阵列输出特性发生显著变化;仿真计算时间与光伏阵列的规模呈近似线性关系,采用分布式计算或减少离散点数都可以显著提高计算速度。本算法物理意义清晰、易于实现,为实际光伏阵列的分析与控制奠定了基础。

Output power of PV generation is undulatory and random.In order to improve the predictability of PV generation and accuracy of maximum power point tracking(MPPT),it is necessary to study the shade effect on PV array’s output characteristics in depth.First,high dimension mathematical model of PV array was constructed based on PV module unit,which considering bypass diode and blocking diode effect.And a fast simulation algorithm for PV array’s output characteristic computing was proposed,that was applicable to different random shade conditions and easy to realize distributed computing.Simulation results under different shades demonstrate that PV array’s output characteristics are closely related to distribution area and irradiance of shade.Meanwhile output characteristics of PV array are affected by shade significantly.Computing time is approximately linear related to PV array scale,and computing speed could be advanced by adopting distributed computing or reducing total number of discreted points.The proposed algorithm,which has clear physical meaning and is easy to realize,is groundwork for analysis and control of practical PV arrays.