Investigation on induced voltage of photovoltaic system on complex terrain

Abstract

Abstract Large-scale photovoltaic (PV) systems are normally installed on wide-open area for converting sunlight into electricity. They face a great challenge of lightning strike. A computational model for lightning-induced voltage on PV system is proposed in this article based on finite-difference time-domain (FDTD) method. Both the medium property and electromagnetic wave propagation are considered. The lightning-induced voltages for PV systems on complex terrain, including flat land, lake and mountain, are investigated for the first time. It suggests that the lightning-induced voltage is strongly dependent on the ground conductivity due to the variation of wave reflection coefficient at the interface. The terrain with low conductivity and great permittivity would result in a large voltage, which becomes higher as the mounting height increases. The characteristics for that on lake are completely different from that on land; the lightning threat for floating PV is relatively small. The electromagnetic field, along with the propagation path, leads to the distinction on mountain. The V-shaped terrain has a greater risk; the mountain slope also plays a role. The proposed method is compared with existing methods and further validated. The results provide guidance for lightning protection design for PV system on complex terrain.