Abstract:With the promotion of the strategic goal of carbon peaking and carbon neutrality, photovoltaic power generation has become an important part of electricity energy. Photovoltaic system is composed of a large number of power electronic devices and equipment, which is easy to be damaged by lightning strikes, and there is a lack of effective lightning protection theoretical design guidance. In view of the lack of effective methods for grounding modeling of photovoltaic modules and electromagnetic transient calculation of hybrid AC/DC systems, this paper studied the Partial-Element-Equivalent-Circuit (PEEC) and Multiple-Transmission-Line (MTL) hybrid method, used PEEC method to complete the modeling of complex multi-conductor systems, and used MTL method to complete the modeling of long-distance transmission lines. The grounding effect of photovoltaic array and the influence of grounding layout of whole system were discussed. The results show that when the DC side of the PV system was hit by direct lightning, the DC line would produce serious over-voltage. Connecting the PV array to the whole AC system helps to reduce the over-voltage of the system. In order to ensure the safe operation of the photovoltaic system, lightning protection devices need to be installed at both ends of the cable, and both ends of the cable sheath need to be grounded.