Power Quality Analysis for Selective Harmonic Compensation in Islanded AC Nanogrid

A comprehensive power quality analysis is conducted on an AC nanogrid system comprising of a 2-level voltage source inverter (2L VSI) and a 3-level T-type inverter (3L T-type). The research investigates voltage and current stability, harmonic distortion, and power quality performance under diverse load conditions, including linear, nonlinear, and unbalanced load scenarios. Employing the PLECS simulation environment, the study evaluates power quality indicators against European electric grid standards, specifically focusing on total harmonic distortion (THD), and voltage imbalance. The investigation uses an integrated control scheme incorporating multiple second-order generalized integrators (MSOGI), droop control, virtual impedance loops, and discretized proportional-resonant (PR) controllers. Fourier analysis techniques are applied to comprehensively assess harmonic characteristics and power quality metrics. The research contributes critical insights into nanogrid system performance, addressing emerging challenges in distributed energy infrastructure and providing a methodological framework for power quality evaluation in advanced electrical systems.