Due to the exposure characteristics of the installation location of photovoltaic array, the risk of direct lightning strike is high, such as:

① Direct lightning strike (direct strike on photovoltaic panels);
② indirect impact (surge impact of photovoltaic modules, combiner boxes, inverters, etc.);
③ impact on other lines (direct impact on signal lines or surge)
We must consider accidental operational losses such as downtime caused by lightning strikes, especially in high-power power generation applications. In addition, the risk of operating overvoltages must also be considered when PV systems are located in industrial field applications. At the same time, the risk level is directly related to the ground flash density and the exposure of local lines.

1. For low-voltage photovoltaic application systems, taking small residential buildings and office building rooftop power stations as examples, surge protection device must be performed on the DC side of the inverter connected to the photovoltaic array and the AC side of the inverter connected to the grid system. If the distance between the protective equipment (inverter or PV array) and the upstream spd is more than 10m, it is recommended to install an additional surge protector nearby to improve the protection capability.

2. Medium to large scale photovoltaic power generation systems can be installed on industrial test and service facilities. In order to avoid downtime and production losses due to direct or indirect lightning strikes, it is critical to install surge protectors at critical locations on equipment critical power and communication networks.

3. If the building does not have an air-termination system installed, it must be mandatory to install type 2 surge protectors on the AC and DC incoming lines of the inverter. On the photovoltaic side, for cables longer than 10m, a surge protector must be added at each end of the working cable.

4. If an air-termination system is installed, type 1 surge protection device must be installed on the AC input. On the DC side as well, Type 1 surge protectors are necessary in case the air-terminations are not installed to maintain an effective safe distance.