A Topology-Reconstructed Minimum-Current-Stress Modulation for a Single-Phase Isolated DC–AC Converter

Isolated dc–ac converters, driven by their high-power density and efficiency, have become a compelling alternative for line-frequency transformer-based dc–ac converters in applications requiring isolation and bidirectional power flow. In this article, a single-phase isolated dc–ac converter is studied, and a modified topology-reconstructed minimum-current-stress (MCS) modulation is proposed for achieving high efficiency and superior power quality. This method discusses the topology reconstruction of the dc–ac converter and treats it as two dual-active-bridge (DAB) dc–dc converters, allowing the dc–ac converter to inherit the efficiency optimized methods of the DAB converter. Then, by combining the MCS modulation of the high-efficiency DAB converter, the modified topology-reconstructed MCS modulation is proposed for the single-phase isolated dc–ac converter. In addition, superior power quality can also be achieved by using the proposed method. Finally, a small-scale experimental platform is constructed to verify the effectiveness of the proposed topology-reconstructed modulation scheme for the single-phase isolated dc–ac converter.