Abstract:With the promotion of the dual carbon target, photovoltaic power (PV) generation has become an important part of electricity energy. Photovoltaic systems are composed of a large number of power electronic devices and equipment. Over-voltage generated on the DC side during lightning strikes can easily cause damage to power electronic devices and equipment. At present, there is a lack of effective theoretical guidance for lightning protection in photovoltaic systems, especially in the modeling of photovoltaic module grounding and electromagnetic transient calculation of hybrid AC/DC systems, which still have certain gaps. In response to the above issues, based on the partial element equivalent circuit (PEEC) method and the multi transmission line (MTL) method, this paper proposes a PEEC-MTL (Partial Element Equivalent Circuit Multiple Transmission Line) hybrid method. We conducted in-depth research on the grounding effect of photovoltaic arrays and the impact on the overall system grounding layout. 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 helped to reduce the over-voltage of the system. In addition, installing lightning protection devices at both ends of the cable and grounding both ends of the cable sheath were more conducive to equipment safety.