A simple test-bench to evaluate partial shading effects on the MPPT efficiency of a PV inverter

This paper focuses on the performance evaluation of grid-connected photovoltaic (PV) inverters in terms of static maximum power point tracking (MPPT) efficiency. A simple test-bench set-up is proposed to accurately analyze the behavior of commercial inverters applied to PV plants under partial shading conditions. The system performs a real-time monitoring of the operating point of the PV plant during the MPPT and compares the measured data to a traced I-V curve with the aim of distinguishing the dc power losses induced by shading from those ascribable to MPPT failures. A commercial inverter is tested for a PV string under sunny and partial shading conditions as a case study.