Abstract
This paper proposes a four-degrees-of-freedom modulation scheme to mitigate the conduction and switching losses in a dual-active-bridge (DAB) series-resonant converter. Under wide-range variations in the voltage gain and output current, the increased reactive power and root-mean-square tank current can contribute significantly to the conduction loss in a DAB converter, while the occurrence of hard switching leads to a switching loss and an increased device stress. The proposed modulation scheme utilizes internal, external phase shifts, and switching frequency as modulation parameters to achieve zero reactive power, minimum-tank-current, and complete soft-switching operation. Analysis of the proposed modulation scheme is given for both buck- and boost-mode operations. The proposed modulation scheme is validated by means of a 1-kW experimental prototype of a DAB series-resonant converter operating at 100 kHz, designed to interface a supercapacitor with a rated output voltage of 48 V to a 250-V dc bus. The effectiveness of the proposed topology for charging/discharging a supercapacitor under wide-range variations in the voltage gain and output current is verified by simulations and experimental results. A maximum efficiency of 97.7% is recorded from the experimental prototype (The experimental setup used for measuring converter's efficiency is shown in the supplementary material).
Original language | English |
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Article number | 8438973 |
Pages (from-to) | 1065-1081 |
Number of pages | 17 |
Journal | IEEE Transactions on Power Electronics |
Volume | 34 |
Issue number | 2 |
DOIs | |
Publication status | Published - Feb 2019 |
Keywords
- Dual-active-bridge (DAB) converter
- four-degrees-of-freedom (4-DOF) modulation strategy
- power loss minimization
- soft switching
- supercapacitor
- zero reactive power
ASJC Scopus subject areas
- Electrical and Electronic Engineering