局部异物遮挡状态下光伏单元输出特性与故障诊断方法

OUTPUT CHARACTERISTICS AND FAULT DIAGNOSIS METHOD OF PV UNIT UNDER PARTIAL SHADING

为研究局部异物遮挡状态下光伏单元输出特性,并对遮挡面积与程度进行定量判断,基于太阳电池等效电路模型,建立光伏单元在局部异物遮挡状态下的输出特性模型,获得短路电流、开路电压变化规律,确定电路在局部异物遮挡状态时的诊断特征量,通过对特征量的计算,判断异物遮挡面积与程度。此外,通过搭建光伏发电系统,实验证明光伏单元在局部异物遮挡状态下输出特性模型的有效性和诊断特征量计算方法的可靠性。

In order to study the output characteristics of photovoltaic unit under partial shading and quantitatively judge the shading area and degree,the model of PV unit under partial shading is established based on the equivalent circuit model of solar cell and the variation principle of short circuit current and open circuit voltage is obtained.By calculating the characteristic quantity,the area and degree of partial shading can be judged.A set of small photovoltaic series power generation system is built and the experimental results showed that the output characteristic model of series photovoltaic circuit under partial shading is effective and the calculation method is feasible.