Impact of lightning impulse voltage on polycrystalline silicon photovoltaic modules

Lightning is one of the factors that cause Photovoltaic (PV) system to fail. Both direct lightning strike and lightning induced voltages pose electrical stress to the PV system. The PV modules inside PV systems, like any other electric equipment, will be degraded under this stress. In this paper, experiments of applying standard lightning impulse voltages 1.2/50 μs of positive polarity (peak voltage 15 V, 30 V, and 90 V) on a type of polycrystalline silicon photovoltaic module were performed. Comparisons of their dark I-V characteristics curves and I-V characteristics are presented. Studies show that the repeated impulse stresses causes a drop in the modules power output when the stress voltage is 30 V and 90 V.