根据太阳电池直流模型和最大功率点数学条件，推出短路电流、开路电压、最大功率点电流和电压 以及填充因子随日照强度变化的数学关系式；并选取２个电池分别计算出在不同日照强度下上述电池参数随日 照强度的变化率。验证了短路电流和最大功率点电流是近似跟日照强度成正比，开路电压和最大功率点电压是 近似跟日照强度的自然对数成正比。并提出了填充因子随日照强度的变化关系不具有简单的函数形式，而对不 同的太阳电池其变化关系也迥异。最后用Multisim的模拟结果检验了理论分析计算的正确性。

Based on the solar cell DC model and the mathematic expression of maximum power point,  the equations describing short circuit current,  open circuit voltage,  maximum power current,  voltage and filling factor varying along with the illumination intensity are deduced and calculated with two real solar cells data. The fact that short circuit current and maximum power current are proportional to the illumination intensity, and open circuit voltage and maximum power voltage are proportional to the natural logarithm of illumination intensity is certified. The relation of filling factor varying along with the illumination intensity is not a simple functional expression and effected by the solar cell model parameters is present. A simulated experiment is established to valid the theoretic analysis and calculating by Multisim.