Quasi-Clamped ZSI With Two Transformers

Abstract

In this article, we present a new type of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Z</i> -source inverter (ZSI) that replaces two inductors in the original quasi-ZSI with two transformers. It can produce a very high output voltage with the high value of the modulation index. Moreover, it enables both to provide a better power quality of output and to reduce the switching loss. In particular, the proposed quasi-clamped ZSI with two transformers give a unique solution to obtain high gain by reducing the turns ratio, rather than increasing it. Also, the leakage inductance of the transformer might cause huge voltage spikes across the inverter bridge. To deal with this problem, an effective clamping technique is proposed. As a result, this increases the overall efficiency of the system by utilizing the low-power switching devices. The characteristics of the proposed quasi-clamped ZSI with two transformers are comprehensively discussed with the detailed theoretical analysis. Thereafter, its performances are evaluated by both simulation and experimental tests.