Power Enhancement and Hotspot Reduction of a Rooftop Solar PV Array Using MOSFETs

Abstract

In photovoltaic (PV) panels, the reliability issue known as “hot spots” occurs when an improperly matched cell warms up substantially, reducing the solar PV panel's output power performance. Hot areas can cause solar PV cell temperatures to rise, causing encapsulation damage and a second failure. Both of these breakdowns cause the PV panel to sustain lasting damage. Hotspots occur when there is any imperfection in solar cells, such as cracks, improper soldering, or mismatching. In this paper, hotspots that occurred due to partial shading are mainly focused on analyzing the effect of panel performance because of shading; different partial shading patterns like horizontal shape, L-shape patterns, and diagonal shape patterns are considered. A MATLAB/Simulink model for a 7x2 array size solar panel connected in series-parallel arrangements has been developed here, and all these partial shading patterns are considered. Previously, bypass diodes were connected across each module to increase the efficiency of solar panels under shading conditions. In this paper, two different arrangements are taken: in the first, MOSFETs are connected across every 14 modules, and in the second, alternate bypass diodes and MOSFETs are connected across each module. This study compares conventional hotspot mitigation techniques power-voltage characteristics with the two novel hotspot mitigation techniques.