Abstract
This paper proposes a reconfigurable dual-active-bridge (DAB) converter that is capable of switching between two converter structures for enhancing its performances at different output power levels. For 50%-100% load, the converter operates in full-bridge mode and achieves soft-switching in all switches independently of the input-to-output voltage ratio. Below 50% load, the converter is reconfigured to operate in half-bridge mode for reduced circulating current and improved light-load efficiency while maintaining the desired soft-switching characteristic of full-bridge mode. The achievement of soft-switching is aided by the use of a tuned LCL resonant tank, which enables an accurate prediction of the phases of tank currents with respect to tank voltages, and therefore simplifies the realization of soft-switching. The effects of dead time are discussed and expressions for guiding the selection of appropriate dead time for ensuring soft-switching in practical implementation are derived. The proposed converter and the modulation scheme are experimentally verified with a 1.6-kW converter prototype, which demonstrates their merits in comparison with a nonreconfigurable, full-bridge DAB topology and conventional modulation schemes.
Original language | English |
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Article number | 8424871 |
Pages (from-to) | 4195-4207 |
Number of pages | 13 |
Journal | IEEE Transactions on Power Electronics |
Volume | 34 |
Issue number | 5 |
DOIs | |
Publication status | Published - May 2019 |
Keywords
- Dual-active-bridge (DAB) converter
- immittance network
- reconfigurability
- resonant converter
- soft-switching
ASJC Scopus subject areas
- Electrical and Electronic Engineering