Impact Factor:4.472
DOI number:10.1109/JESTPE.2019.2941583
Journal:IEEE Journal of Emerging and Selected Topics in Power Electronics
Key Words:Resonant converters; Topology; Pulse width modulation; Bidirectional power flow; Rectifiers; Clamps; Constant power limitation; constant voltage gain; isolated bidirectional dc– dc converter; natural bidirectional power flow
Abstract:For the high-power Li-ion battery (LIB) formation and grading system, using a multistage conversion structure, an isolated bidirectional dc-dc converter with a high input voltage, and a large output current is needed to achieve isolation and a relatively fixed voltage conversion gain. This article proposes a modulation strategy and modifies the topology to achieve natural bidirectional power transfer, automatic power sharing, and power limitation for an input-series-output-parallel (ISOP) LLC-DC transformer (DCX) converter. First, an active pulsewidth modulation (PWM) strategy is proposed to avoid synchronous rectifier (SR) sensing and to achieve the natural bidirectional power flow for each submodule. The resonant current always keeps discontinuous, and the conversion gain can keep constant if ignoring the conductive resistance. Second, clamping diodes are added in the conventional LLC converter to limit the inrush current during startup, and to achieve a constant power limitation under an overload condition. Third, with the proposed modulation, the power sharing of the two-module ISOP LLC converter is analyzed and compared with the conventional ISOP LLC converter. Finally, experiments based on an 8-kW (output: 15 V/533 A) prototype composed of the two-module ISOP LLC converter are conducted to verify the effectiveness of the proposed solution.
Co-author:Xie, Shiming, Han, Hua, Su, Mei, Sun, Yao, Wang, Hui, Liu, Yonglu, Xiong, Wenjing
First Author:Chen, Xiaoying
Indexed by:Journal paper
Correspondence Author:Xu, Guo
Document Code:20115052
Discipline:Engineering
First-Level Discipline:Electrical Engineering
Volume:8
Issue:4
Page Number:3618-3632
ISSN No.:2168-6777
Translation or Not:no
Included Journals:EI、SCI
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