Computation of Power Extraction from Photovoltaic Arrays under Various Fault Conditions

Abstract

Photovoltaic (PV) faults such as partial shading, bypass-diode defects, degradation of PV modules, and wiring issues greatly affect the power output and cause various peaks in P-V curves of a PV system. Although, commonly used Total-Cross-Tied (TCT) scheme in PV arrays is considered instrumental for reducing power losses there lies a great scope to evaluate power extraction through reconfiguration of modules with different PV materials. This paper presents detailed investigation of power extraction using number placement reconfiguration method under numerous faults. PV power extraction is carried out and compared with three different interconnections of PV modules, including series-parallel (SP), bridge-link (BL) and TCT. In order to conduct a thorough investigation and better evaluate the performance of PV arrays, we have studied reconfiguration of PV modules with polycrystalline and copper indium gallium selenide (CIGS) PV technologies. In addition, this paper contains detailed quantification of the impact of the studied PV faults on power grid. The results obtained in MATLAB/Simulink demonstrate that CIGS PV technology performs better than polycrystalline in terms of power output during different faulty conditions. It becomes evident from the presented results that optimal reconfiguration of PV arrays can increase the power extraction from PV system with reduced number of P-V peaks. Hence, leading to improved performance of the PV system.