3.2.1. Experimental Method

After multi-physical field simulation analysis, Sample C was selected for experimental verification. As shown in Figure 11, a large current experimental platform for simulating lightning stroke was set up in the laboratory. Sample C was horizontally placed on an insulating table. One copper wire was used to connect the output end of Impulse Current Generator (ICG) to the expected lightning striking point on the metal frame. Another copper wire was used to connect the other end of the metal frame to the grounding electrode.

**Figure 11.** Lightning current withstand performance experiment (**a**) Schematic diagram of experimental platform; (**b**) Layout of experimental setup.

According to the IEC standard [21], the lightning conductor of the highest grade (H-grade) should withstand the impulse current with 100 kA peak value and 2.5 MJ/Ω specific energy, which represents the equivalent energy of the first return stroke component (FRSC) of nature lightning. Since the metal frame of the BIPV module is easy to be struck by lightning, it can function as the lightning receptor on the buildings. The PV module frame should also meet the H-grade impulse current withstand level. In this paper, Haefely SSGA 180–200 ICG was used to output the impulse current with 100 kA peak value and

2.5 MJ/ Ω specific energy. Each sample receives three shots. During each shot, the current waveform was measured by a Rogowski coil. The status of the metal frame is observed after each shot to check whether it is damaged.
