Electrical Degradation of Photovoltaic Modules Caused by Lightning Induced Voltage

Lightning strikes can lead to failure and cause degradation of Photovoltaic (PV) modules. The paper studies the electrical degradation of a polycrystalline silicon PV module (rated 6 V, 1.5 W) caused by lightning induced voltage. The PV module was subjected to 1.2/50 mu s standard lightning impulse voltages with positive polarity. The peak voltage of these testing lightning impulse voltages are 1000 V. Two groups of experiments were performed. Samples in test group one were subjected to lightning impulse voltage tests up to 3000 impulses. Their Current-Voltage (I-V) characteristics were presented. In test group two, heat treatment was performed to a PV module until bubbles appeared in its insulation layer. Then, this module was taken into lightning impulse voltage test at the same test condition as in test group one. Comparisons are made between test group one and two. The lightning impulse voltage causes strong degradation of the sample with bubbles that leads to breakdown of the PV module.