A Two-Phase Interleaved Bidirectional DC-DC Converter With Asymmetrical Duty Limit Control for Wide-Range DC-Bus Voltage Applications
Ching‐Ming Lai, Wei-Hsuan Lin, Hao-En Liu, Shiqiang Liu, Tomokazu Mishima, Jiashen Teh
Abstract
The two-phase interleaved charge-pump bidirectional dc/dc converter topology (ICPBDC) exhibits an excellent performance in terms of enhanced voltage gain, reduced conduction loss and switch stress, fast transient response, and high power density. However, the applicability of ICPBDC topology is restricted because of its operating duty cycle. This article presents a cost-effective asymmetrical duty limit control (DLC) strategy for wide-range DC-bus voltage and full operating range, which includes bidirectional power flow and inherent current-balancing characteristics. The realization of charge and discharge modes of ICPBDC with asymmetrical DLC strategy are demonstrated for an electric vehicle-connected DC-microgrid (EV-DCMG) with wide-range DC-bus voltage. Furthermore, the operating principles, steady-state analyses, and closed-loop control of the converter are illustrated. Finally, a prototype with 500 W power rating has been implemented which verifies a wide voltage gain range for this converter between the adjustable DC-bus voltage (200–380 V) and the constant low-side voltage (60 V). In both charge and discharge modes, the converter achieves maximum efficiencies above 97.51%. The experimental results also validate the feasibility of the proposed concept.