Comparative Performance Analysis of Healthy and Potential Induced Degraded c-Si PV Modules Under Partial Shading Condition

Potential-induced degradation shunting (PID-s) has emerged as a critical reliability concern in crystalline silicon (c-Si) photovoltaic (PV) modules, especially in large-scale installations. This work presents a comparative performance analysis of healthy and PID-s affected PV modules under various partial shading conditions using PSpice-based simulations. A 36-cell c-Si PV module was modeled and divided into two submodules, each with a bypass diode, and corner cells were assigned PID-s characteristics to reflect real-world degradation behavior. The impact of PID-s and partial shading was analyzed through six shading scenarios: single-cell shading, row shading, column shading, diagonal shading, row shading with bypass diode failure and column shading with bypass diode failure. The relative power output was calculated for both healthy and degraded module across a full range of shading intensities. Results reveal that while healthy modules perform better under low shading conditions, PID-s affected modules exhibit lower initial performance. Notably, under high shading levels, the relative performance gap narrows, with PID-s modules occasionally outperforming healthy ones due to their already diminished output power. The findings emphasize the importance of PID mitigation in PV system design and highlight the complex interplay between degradation and environmental stressors like shading.