Resonant and a new disturbance-observer combined control for off-grid voltage source inverter

<span lang="EN-US">This paper presents a new control strategy based on the combination between resonant controller and disturbance-observer (RSCDO) for stand-alone four-leg Voltage Source Inverter (VSI). The aim of is to regulate inverter output voltage, reducing as much possible voltage Total Harmonic Distortion (THDv) in every load condition. allows adjust fundamental harmonic, whereas disturbance observer designed compensating harmonics when non-linear loads have be fed. proposed has been tested using 40 kVA three-phase 4-leg VSI dedicated board, which uses National Instruments System-on-Module sbRIO-9651. Experimental results demonstrate good behavior RSCDO reject well dynamic response.</span>