Research on lightning overvoltages of solar arrays in a rooftop photovoltaic power system

Lightning overvoltages threaten the safe operation of the photovoltaic (PV) power system. This document uses the generalized modified mesh current method and establishes a time-domain multiport model of thin-wire system to simulate the lightning transient process of the solar arrays in a rooftop PV power system with and without the external lightning protection system. Different factors of the PV power system are simulated in order to study the effects of these factors on the induced lightning overvoltages. The simulation results show that the induced lightning overvoltage of the solar arrays in a rooftop PV power system is highly dependent on the lightning striking position, the lightning current amplitude, the building's height, the soil resistivity, and the distance to the external protection system. Therefore, when choosing the SPD configuration for a PV power system, the factors mentioned above should be considered comprehensively.

► The generalized modified mesh current method and a time-domain multiport model of thin-wire system are established to simulate the lightning transient process of the solar arrays in a rooftop PV power system.
► The influence of different factors of the PV power system on the induced lightning overvoltages of the solar arrays are analyzed, including the lightning striking spot, the lightning current amplitude, the building height, the soil resistivity, and the distance between the solar arrays and the external protection system.
► The induced lightning overvoltage of the solar arrays in a rooftop PV power system is highly dependent on all simulated factors.
► The influence of different factors of the PV power system on the induced lightning overvoltages of the solar arrays should be considered comprehensively in choosing the SPD configuration for the PV power system.