External Lightning Protection and Earthing to Reduce Stress on SPDs within Electrical Equipment in Photovoltaic Plants

Abstract

Lightning current transients injected onto the PV modules in large Solar Power Plants (SPPs) may cause damage to downstream connected systems, resulting in permanent equipment failure and power production down time. Surge protective devices installed to protect electronic equipment on SPPs will not be able to withstand the peak lightning currents without sufficient energy dissipation through the SPP. With the correct implementation of external lightning protection and earthing meshes, it is shown that the surge protection is not overstressed due to sufficient energy diversion and dissipation in the SPP before reaching critical equipment. The resultant current distribution, transient waveform and specific energy are calculated at critical locations in the PV field through XGSLab simulations. Advantages are shown for the strategic and cost-effective design considerations with regards to earthing, and how it reduces stress on equipment and surge protective devices during lightning events.