Attenuation of hotspot phenomenon in PV systems

Abstract

ABSTRACT PV waste management is a looming problem and a growing concern for environmental engineers and energy policymakers, as the early PV installations are approaching their end-of-life. Hence, improvement of PV reliability and prevention of early failures has now become more important than ever. Notably, the formation of hotspots in PV cells under partial shading and other mismatch conditions remains a dominant cause of early failures in PV modules. In this study, we undertake an experimental investigation to assess the effectiveness of the extant bypass mechanism in preventing hotspot formation in PV modules. The findings reveal several limitations associated with the conventional bypass approach. Although the bypass diode partially fulfills its intended purpose within a string array configuration, its effectiveness is entirely compromised when connected in the configuration of real-world installations, such as in a series-parallel (SP) array. The hotspot temperature in the SP array increased up to 70.7°C under partial shading conditions at the operating point (i.e., at MPP), whereas no hotspot was created (below 46.1°C) in a string array, except in the single-cell shading scenario. To make the bypass circuits effective, in the present work, a novel bypass strategy is proposed.