局部阴影遮挡的太阳电池组件输出特性实验研究

结合太阳电池双二极管与雪崩击穿效应数学模型,设计太阳电池组件遮挡实验,并对组件性能进行实际测试。分别在有、无旁通二极管两种情况下,分析比较单片太阳电池小比例(1%～10%)、大比例(10%～100%)遮挡及多片电池阴影遮挡的太阳电池组件输出的I-V及P-V特性曲线。结果表明,有、无旁通二极管情况下,组件单片电池被遮挡1%～10%,整个组件输出功率下降比例均不超过2%,同一串电池片之间可允许存在小的功率差异或表面辐照强度差异(<5%)。同组件无旁通二极管多个电池遮挡实验显示,电池出现热斑效应时会被反向击穿,实验组件击穿电压约15V,为避免热斑损害,组件中应对少于15/0.6=25片串联电池并联一个旁通二极管。

EXPERIMENTAL STUDY ON CHARACTERISTICS OF PARTIAL SHADED SOLAR MODULE

Basing on the theoretical calculation and analysis,experiments for shading test of module were designed in this paper.I-V(current and voltage) and P-V(power and voltage) characteristics of modules were tested and analyzed when one or multi cells were shaded by low percentage shading(1%～10%) and large percentage(10%～100%) in which by-pass diodes would be designed or not.According to the test result,the output power(Pm) of solar module decreased slightly(less than 2%) while one of cells was shaded by 1%～10% in the module.So slightly difference among power of cells or asymmetrical radiation(<5%) on cells’surface in one module is acceptable.It was shown in the multi-cell shading test that cell would be destructed by reverse current while the reverse voltage reaches 15V when hot spot emerged.To avoid hot spot damage,it is necessary to connect at least one by-pass diode to the string as the pieces of cells is less than of 25(15/0.6=25).