Optimizing bypass diode performance with modified hotspot mitigation circuit

Abstract

The frequently changing environmental conditions have a substantial impact on the performance of photovoltaic (PV) systems, which makes it challenging to ensure its high-performance ratios. Mismatch of solar cells is one such factor, that leads to formation of hotspot in solar PV systems and reduces its reliability. The experimental findings presented in this article shows the inadequacy of conventional bypass circuit to protect the shaded PV module from adverse thermal impacts of small shaded areas at all operating points and for large shaded areas at maximum power point. Its performance is assessed through I-V, P-V, and bypass characteristic of the PV system for various partial shading scenarios. Previous attempts to mitigate hotspots were considered complex and costly for practical use. This article suggests a cost-effective remedy by simplifying the triggering of MOSFET based hotspot mitigation circuit. The performance of the proposed circuit is demonstrated using a 3x3 TCT connected PV array and its efficacy is confirmed via thermographic images, validating the enhanced reliability aspect. The findings reveal that the implemented solution effectively reduces the temperature of the shadowed cell(s) by up to 27.45 % when compared with conventional bypass circuit.