Dynamic Bypass Controller With Regenerative Feedback for Hot-Spot-Free PV Modules

Abstract

In the photovoltaic (PV) sector, ensuring the optimal performance and longevity of modules is vital for maximizing return on investment. One of the critical challenges in PV systems is the occurrence of localized overheating, or hot spots, which can lead to irreversible damage, reduced efficiency, and even fire hazards. This article presents a novel approach to mitigating hot spots at the submodule level through a dual-switch configuration. Unlike traditional bypass diodes, the proposed design features a dynamic bypass and disconnection circuit that adapts to bypass events, disconnecting the affected cells and reconnecting them once the bypass condition ceases. This article details the operation of this circuit and its impact on submodule performance under various shading scenarios. Experimental tests were conducted to compare the proposed solution with a conventional submodule protected by a standard bypass diode, under the worst case scenario of a malfunctioning cell. Infrared thermography was employed to analyze the temperature distribution across the submodules. The results show that, in the submodule with the proposed circuit, the temperature of the faulty cell remains close to that of the other cells, whereas the standard bypass diode causes the shaded cell to overheat significantly. This demonstrates the potential of the proposed design in enhancing PV system reliability, preventing hot spots, and improving thermal management.