A novel comparative robustness index for evaluating the performance of grid-tied PV inverters

Increasing the integration of PV systems requires more reliable and more robust PV inverter architectures. This paper presents a novel index called Smart Inverter Robustness Index (SIRI) to evaluate the robustness of grid-tied PV inverters. Proposed index considering four major operational characteristics such as efficiency, Total Harmonic Distortion (THD), Maximum Power Point Tracking (MPPT) effectiveness and Power Factor (PF) compliance provides a comparative evaluation of PV inverters. Robustness of a single-phase grid-tied PV inverter under varying manufacturing inaccuracies is analyzed by using SIRI index and a boundary for robust operation is determined. Statistical analysis and Random Latin Hypercube Sampling (RLHS) algorithm are used to model the impact of physical variations of passive components on PV inverter operation with minimum sampling points. Effectiveness and feasibility of proposed index is verified by simulation and experimental results of a single-phase grid-tied PV inverter.