3.2.2. Experimental Results and Analysis

According to the experimental method of Section 3.2.1, a large impulse current experimental platform was built. The impulse current with amplitude of nearly 100 kA and waveform of 10/350 μs was applied to Sample C by using Haefely SSGA 180–200 ICG. The first impulse current waveform is shown in Figure 12. Table 2 illustrates the parameters of the lightning current in three shots. The waveform of lightning current is defined as T1/T2, where T1 indicates the peak time of lightning current and T2 indicates the time from the beginning to the attenuation to 1/2 amplitude. Transfer charge Qs is the time integral of lightning current in duration; Specific energy W/R is the time integral of lightning current squared in duration.

**Figure 12.** The first impulse current waveform.

**Table 2.** Impulse current parameter.


Due to the impedance of the experimental loop, the impulse currents flowing through the metal frame were a little smaller than 100 kA, i.e., 96.313 kA, 96.508 kA and 96.938 kA respectively. The specific energies of the impulse currents flowing through the metal frame were 2496 MJ/ Ω, 2426 MJ/ Ω and 2451 MJ/ Ω respectively. After three shots, the experimental results showed that the metal frame of Sample C had no signs of deformation and solar cells were not damaged, which was consistent with the results of the thermoelectric coupling analysis model. This shows that the metal frame of BIPV module has adequate lightning energy withstand capability.
