Design of high-efficiency dual-input interleaved DC-DC converter

Abstract

This study develops a high-efficiency dual-input interleaved dc-dc converter for reversible power sources, e.g., reversible solid-oxide fuel cell (RSOFC) and rechargeable battery. The proposed converter can convert low-voltage reversible power sources to a high-voltage dc bus individually or simultaneously by the phase-shift control, also can step-down the high-voltage dc bus to charge the power sources. Moreover, the reversible power sources can charge each other respectively. According to various situations, the operational states of the proposed converter can be divided into four states including a single-input step-up state, a dual-input step-up state, a dual-output step-down state, and a dual power source step-up/step-down state. In addition, the inductors in the proposed converter are designed to operate in synchronous conduction mode (SCM) for achieving turn-on zero-voltage-switching (ZVS) of all switches. Furthermore, the effectiveness of the designed circuit topology and the ZVS properties are verified by experimental results of a 5kW-level prototype, and the goal of high-efficiency conversion can be obtained.