A novel reconfiguration technique for improvement of PV reliability

Abstract

Generation of the hot spot in photovoltaic cells (PV) cells under partial shading conditions (PSC) is a persistent issue associated with PV systems which not only affects the PV performance but also increases the cell temperature (up to 400 °C in extreme cases), and thereby causes premature failure. This article presents a novel technique to prevent the reverse breakdown and thereby mitigate the hot spot temperature of the PV cells under partial shading by reducing reverse current through automated reconfiguration of PV array. The efficacy of the proposed technique is evaluated by simulating eight different shading scenarios, under which the reconfiguration algorithm automatically switched different PV configurations based on the nature of the shading pattern. The performance of the PV arrays is evaluated using IGBT as the switching device, and the performance is compared with an ideal switch-based circuit. The proposed technique is found to reduce the reverse voltage and reverse current and through the affected modules and thereby increase the reliability index in 82% of the cases. Hence the proposed reconfiguration algorithm is expected to increase the PV reliability and thereby increase the performance ratio of the PV projects, especially which are susceptible to frequent partial shading conditions.