TY - JOUR
T1 - A Dual Active Bridge Converter with an Extended High-Efficiency Range by DC Blocking Capacitor Voltage Control
AU - Qin, Zian
AU - Shen, Yanfeng
AU - Loh, Poh Chiang
AU - Wang, Huai
AU - Blaabjerg, Frede
PY - 2018/7
Y1 - 2018/7
N2 - A Dual Active Bridge (DAB) converter can achieve a wide high-efficiency range when its input and output voltages are equal, assuming a 1:1 turns ratio for its isolation transformer. If its input or output voltage is doubled, efficiency of the DAB will drop significantly, because of the introduction of hard switching and high circulating power. Thus, a new modulation scheme has been proposed, whose main idea is to introduce a voltage offset across the dc blocking capacitor connected in series with the transformer. Operational principle of the proposed modulation has been introduced, before analyzing its soft-switching area and circulating power mathematically. The final modulation scheme is not difficult to implement, but can help the DAB achieve soft switching, low circulating power, and thereby high efficiency, even with its input or output voltage doubled. These features have been verified by experimental results obtained with a 1.2 kW prototype.
AB - A Dual Active Bridge (DAB) converter can achieve a wide high-efficiency range when its input and output voltages are equal, assuming a 1:1 turns ratio for its isolation transformer. If its input or output voltage is doubled, efficiency of the DAB will drop significantly, because of the introduction of hard switching and high circulating power. Thus, a new modulation scheme has been proposed, whose main idea is to introduce a voltage offset across the dc blocking capacitor connected in series with the transformer. Operational principle of the proposed modulation has been introduced, before analyzing its soft-switching area and circulating power mathematically. The final modulation scheme is not difficult to implement, but can help the DAB achieve soft switching, low circulating power, and thereby high efficiency, even with its input or output voltage doubled. These features have been verified by experimental results obtained with a 1.2 kW prototype.
KW - Dual active bridge converters
KW - Modulation
KW - High efficiency
KW - Soft switching
KW - Circulating power
UR - http://www.scopus.com/inward/record.url?scp=85028707567&partnerID=8YFLogxK
U2 - 10.1109/TPEL.2017.2746518
DO - 10.1109/TPEL.2017.2746518
M3 - Journal article
SN - 0885-8993
VL - 33
SP - 5949
EP - 5966
JO - I E E E Transactions on Power Electronics
JF - I E E E Transactions on Power Electronics
IS - 7
ER -