Circuit model-driven investigation of hot-spot behavior in n-type TBC photovoltaic modules

Against the backdrop of the global energy transition and the ever-growing demand for high-performance photovoltaic (PV) technologies, n-type TOPCon back contact (TBC) modules have witnessed rapid expansion in application scale, thanks to their advantages such as front-side shading-free design and high conversion efficiency. However, industrialized TBC solar cells generally exhibit low shunt resistance, leading to the failure of researchers to effectively identify the hot-spot risks of such modules when conducting tests in accordance with the IEC 61215 MQT09 method. Consequently, the evaluation process is time-consuming with poor accuracy. To address this limitation, this study proposes a two-stage collaborative approach at the substring-module level. At the substring level, an equivalent circuit model was established to simulate the power dissipation characteristics under different local shading scenarios. Meanwhile, the correlation between power consumption and temperature during hot-spot formation was determined through experiments. The results demonstrate that the temperature trend predicted by the substring model is basically consistent with that of the TBC module. Furthermore, the maximum temperature of the module during outdoor hot-spot occurrence aligns with the expectations verified by the substring model, which confirms the model's accuracy and practical reliability. This two-stage collaborative approach can effectively identify the hot-spot risks of TBC modules, thereby providing an efficient and cost-effective technical method for the hot-spot reliability screening of n-type TBC PV modules.