A Composite Current-Fed LLC Resonant Converter for Wide Input Voltage

The LLC resonant converter is the most commonly used unidirectional isolated DC/DC converter. However, the gain adjustment range of conventional LLC resonant converters is limited and not suitable for applications with wide input voltage. In this paper, a C-LLC resonant converter topology suitable f...

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Bibliographic Details
Published in2022 4th International Conference on Smart Power & Internet Energy Systems (SPIES) pp. 774 - 779
Main Authors Liu, Caifeng, Liu, Shuang, Zhu, Donghai, Yan, Xu, Zou, Xudong
Format Conference Proceeding
LanguageEnglish
Published IEEE 09.12.2022
Subjects
efficiency optimization
Energy
isolated dc-dc converter
LLC resonant converter
Phase modulation
Prototypes
Resonant converters
Soft switching
Switches
Voltage
wide voltage
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Summary:The LLC resonant converter is the most commonly used unidirectional isolated DC/DC converter. However, the gain adjustment range of conventional LLC resonant converters is limited and not suitable for applications with wide input voltage. In this paper, a C-LLC resonant converter topology suitable for wide input voltage range is obtained by improving the current-fed LLC resonant converter. The operational modes and stages of the C-LLC resonant converter employing the basic pulse width modulated + double phase shift modulation (PWM+DPS) are analyzed. Then an optimized modulation strategy for efficiency improvement is proposed by optimizing the soft switching range and current RMS values. Finally, a prototype is built to verify the analysis. The efficiency is improved by up to 5% when the optimized modulation strategy is adopted compared to the conventional LLC resonant conversion at voltage mismatch condition.
DOI:10.1109/SPIES55999.2022.10082514