High voltage gain quasi Z‐source inverter unified with switched three‐winding coupled inductor

Abstract

SummaryThis paper presents a new high voltage gain quasi Z‐source inverter consisting of a switched‐inductor unit. A coupled inductor including three windings is utilized in structure of the switched inductor in a way to increase voltage gain effectively. In addition, the configuration includes an active switch with low number of components that has positive effects on voltage gain and two of its components recycles stored energy of the coupled inductor similar to a clamp circuit. The converter boosts voltage appropriately in low shoot‐through duty cycles and transfers power with a continuous input current, leading to a reduction in losses, requiring smaller output filter and improving the efficiency. Also, the converter can operate in high modulation index for similar voltage gains compared to the other works which improves quality of outputs. Low number of components and fewer cores for inductors are considered during the design of the converter, causing some superiorities for it in comparisons. In addition, the presented converter has appropriate condition from the viewpoint of voltage stress on its diodes. To validate quality of the converter performance, a 240‐W prototype is prepared that converts 35‐ to 60‐V DC to three‐phase sinusoidal voltages where effective voltage of each phase is equal to 110 V.