Thus, this paper presents a preliminary analysis of the parameters and their interactions of the welding process (by parallel-gap resistance welding) of interconnections between solar cells using design of experiments. In this welding process, the cell undergoes a certain level of degradation.
The ununiform temperature field, mismatched thermal expansion coefficient and local plastic deformation during welding are the root causes of residual welding stress. The influence of welding process on the yield of solar cells has been discussed above.
The thickness of silicon wafer is 160 μm, the thickness of PV copper strip is 0.1 mm, the thickness of Sn alloy coating is 15 μm and 25 μm respectively. The physical properties of materials used in solar cell welding are shown in Table 6.
This technique helps in optimizing the best adjustments to obtain the expected results. Thus, this paper presents a preliminary analysis of the parameters and their interactions of the welding process (by parallel-gap resistance welding) of interconnections between solar cells using design of experiments.
Connection of Cells in Photovoltaic Modules. As shown in Fig. 5, the solar cells in the modules with different surface structures of welding strips have no cracks, and there is no open welding, false welding and desoldering, which indicates that it can be used for the subsequent research.
According to IEC61215 standard, the light emitted by solar simulator is vertically incident on the surface of photovoltaic welding strip through glass and EVA. The change of surface structure of photovoltaic welding strip will change the reflection path of light on the surface of photovoltaic welding strip, affecting the size of α 1 in Fig. 1.