Harmonic analysis for space-vector modulated grid-tied Quasi Z-source inverter

Current harmonics produced by power converters are strictly limited to ensure power quality in renewable energy integration systems. Quasi Z-source Inverter (qZSI) is used in such systems as a single stage Buck-Boost DC-AC converter. In this paper, the harmonic performance of space-vector modulated (SVM) three phase grid-tied qZSI is investigated. Traditional SVM and Modified-SVM schemes are analytically evaluated using double Fourier series technique. The current harmonic distortion is evaluated analytically using weighted total harmonic distortion factors. The variations in total and individual harmonic distortion levels versus the change in voltage gain are depicted. Simulation and experimental results at selected operation points are shown for a grid-tied qZSI to verify the analysis.