局部阴影下光伏阵列建模对比分析与改进

摘要

Partial shading makes output current-voltage curve of photovoltaic (PV) array ladder shape,and corresponding power-voltage curve appearing multi local maximum points,so the PV array model under uniform illumination conditions is not suitable for this situation.From the opinion of mechanism model,three types of PV array modeling approach are analyzed and simulated.The merits and shortfalls of different models are summarized.Based on the four-parameter model of PV cells,an improved local shadow PV array model is proposed.The simulation results show that the model not only considers the voltage drop of diode under the local shadow,but also avoids the calculation of open circuit voltage and reduces the amount of calculation.%当光照不均匀或局部阴影时,光伏阵列的输出电流与电压曲线呈阶梯状,功率与电压曲线出现多个局部波峰,均匀光照下的光伏阵列模型已无法准确描述光伏阵列的输出特性.从机理模型的角度,逐一阐述了3种局部阴影下光伏阵列的建模方法,比较和总结不同模型的优缺点以及实现的难易程度,基于工程四参数模型,提出一种改进型的局部阴影光伏阵列模型.仿真结果表明:该模型不仅考虑了局部阴影发生时二极管的管压降,且避免了对阴影电池开路电压的求解,减少了计算量.