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An Isolated Soft-switching Buck-Boost Converter Utilizing
Two Transformers and Embedded Bidirectional Switches on
Secondary-side for Wide Voltage Applications
Abstract:
A dual-phase-shift controlled isolated buck-boost converter is
presented for wide input or output voltage range applications.
Two transformers and a voltage-double rectifier with embedded
bidirectional switch are employed. The primary windings of the
two transformers are in series and the secondary windings are in
parallel. With optimized dual-phase-shift modulation strategies,
zero voltage switching (ZVS) is achieved for both the primaryand secondary-side power MOSFETs in a wide load range. The
reverse recovery problem of rectifying diodes is eliminated as
well. Leakage inductances of the transformers are utilized for
power transferring. The voltage stresses of primary-side and
secondary-side power MOSFETs are clamped to the input
voltage and half of the output voltage, respectively. Besides, the
converter can operate in the buck, balance and boost modes to
achieve a wide voltage range. The operational principles are
analyzed and experimental results of a 1-kW 100-kHz prototype
are provided to verify the effectiveness of the presented
converter.
Existing system:
 Isolated DC-DC converters with wide input/output voltage
ranges have been widely used in the applications of
renewable energy, storage and electric vehicles’ power
systems.
 A novel soft-switching IBB converter utilizing two
transformers and embedded bidirectional switch on
secondary side voltage-double rectifier is presented for
wide voltage range applications.
Proposed system:
 With optimized control scheme, soft switching is achieved
for all MOSFETs and diodes within a wide load range.
 Leakage inductance of transformers is used to for power
transferring and the voltage spike problem is rectified in
this proposed system.
 A unique structure with two transformers and a voltagedouble rectifier is employed in the proposed converter to
decrease the voltage and current stresses of the
transformers and rectifying devices.
Circuit diagram:
Reference:
[1] D. S. Gautam, F. Musavi, W. Eberle, and W. G. Dunford, “A
zero voltage switching full-bridge DC-DC converter with
capacitive output filter for plug-in hybrid electric vehicle battery
charging,” IEEE Trans. Power Electronics, vol. 28, no. 12, pp.
5728-5735, Dec. 2013.
[2] H. Wu, Y. Xing, “Families of forward converters suitable for
wide input voltage range applications,” IEEE Trans. Power
Electronics, vol. 29, no. 11, pp. 6006-6017, Nov. 2014.
[3] Y. Zhao, W. Li, Y. Deng, and X. He, “Analysis, design, and
experimentation of an isolated ZVT boost converter with
coupled inductors,” IEEE Trans. Power Electronics, vol. 26, no.
2, pp. 541-550, Feb. 2011.
[4] Y. Wang, W. Liu, H. Ma, L. Chen, “Resonance analysis and
soft switching design of isolated boost converter with coupled
inductors for vehicle inverter application,” IEEE Trans. Power
Electronics, vol. 30, no. 3, pp. 1383-1392, Mar. 2015.