Isolated DC to Single-Phase AC Converter with Active Power Decoupling Capability Using Coupled Inductor

Abstract

This paper proposes a novel active power decoupling circuit that is integrated with an interleaved boost converter for isolated DC to single-phase AC conversion applications. The proposed isolated converter consists of two full-bridge inverters with a coupled inductor, a small buffer capacitor for active power decoupling, and a diode rectifier. Further, the proposed isolated converter is controlled for active power decoupling and DC to single-phase AC power conversion independently by the coupling inductor and common-mode operation of the interleaved boost converter, respectively. This paper presents the control method of the proposed converter and design criteria of the passive components. In addition, the performance of the proposed isolated converter is demonstrated by the experimental results in order to confirm the validity of the proposed method. As the experimental results, the second-order harmonic due to the double-line frequency power ripple is reduced by 84.5% owing to the active power decoupling capability. Finally, a maximum efficiency of 94.5% is obtained using the proposed converter.