Assessment of PV String Optimizer Circuit Versus String and Central Inverters During Partial Shading Conditions

Abstract

Partial Shading (PS) of PV strings has become an issue of great importance as it causes a significant reduction of the generated PV power. There are numerous techniques that have been developed to mitigate the PS effects such as string inverter configuration and micro-inverter configuration beside maximum power point tracking (MPPT) methods, but most of these techniques are costly or complex. So, there is a demand for a cost-effective and reliable technique to overcome some of the inherent limitations of these techniques. String Optimizer Circuit (SOC) approach along with Global MPPT (GMPPT) the algorithm can be used with one central inverter to enhance the extracted PV power during PS conditions. The SOC approach provides approximately the same power level that extracted from the string inverter approach but with a lower number of semiconductor devices which has a positive effect on the system cost. In this paper, an assessment study is presented to show the effectiveness and the advantages of the SOC-based PV system over the conventional central and string inverter-based systems. MATLAB/SIMULINK software package is used for the assessment. The simulation results are presented to show the effectiveness of the SOC along with the GMMPT algorithm in enhancing the extracted PV power.