ABSTRACT:
This paper presents a hybrid-type full-bridge dc/dc converter
with high efficiency. Using a hybrid control scheme with a simple circuit
structure, the proposed dc/dc converter has a hybrid operation mode. Under a
normal input range, the proposed converter operates as a phase-shift
full-bridge series-resonant converter that provides high efficiency by applying
soft switching on all switches and rectifier diodes and reducing conduction
losses. When the input is lower than the normal input range, the converter operates
as an active-clamp step-up converter that enhances an operation range. Due to
the hybrid operation, the proposed converter operates with larger phase-shift
value than the conventional converters under the normal input range. Thus, the
proposed converter is capable of being designed to give high power conversion efficiency
and its operation range is extended. A 1-kW prototype is implemented to confirm
the theoretical analysis and validity of the proposed converter.
KEYWORDS:
1.
Active-clamp
circuit
2.
Full-bridge
circuit
3.
Phase shift control.
SOFTWARE: MATLAB/SIMULINK
CIRCUIT DIAGRAM:
Fig.
1. Circuit diagram of the proposed hybrid-type full-bridge dc/dc converter.
EXPECTED SIMULATION RESULTS:
Fig.
2. Experimental waveforms for the gate signals and output voltage according to
the operation mode. (a) PSFB series-resonant converter mode when Vd = 350 V. (b) Active-clamp step-up converter when Vd = 250 V.
Fig.
3. Experimental waveforms for soft switching in the PSFB series resonant converter
mode. (a) ZVS turn-on of S1 . (b) ZVS
turn-on and ZCS turn-off of S2
.
Fig.
4. Experimental waveforms for the current stress when Vd = 350 V. (a) Conventional PSFB series-resonant
converter. (b) Proposed converter.
Fig.
5. Experimental waveforms for the input voltage Vd and output voltage Vo
in
the transition-state.
CONCLUSION:
The
novel hybrid-type full-bridge dc/dc converter with high efficiency has been
introduced and verified by the analysis and experimental results. By using the
hybrid control scheme with the simple circuit structure, the proposed converter
has both the step-down and step-up functions, which ensure to cover the wide
input range. Under the normal input range, the proposed converter achieves high
efficiency by providing soft switching technique to all the switches and
rectifier diodes, and reducing the current stress. When the input is lower than
the normal input range, the proposed converter provides the step-up function by
using the active-clamp circuit and voltage doubler, which extends the operation
range. To confirm the validity of the proposed converter, 1 kW prototype was
built and tested. Under the normal input range, the conversion efficiency is
over 96% at full-load condition, and the input range from 250 to 350 V is guaranteed.
Thus, the proposed converter has many advantages such as high efficiency and
wide input range.
REFERENCES:
[1]
J. A. Sabat´e, V. Vlatkovic, R. B. Ridley, F. C. Lee, and B. H. Cho, “Design considerations
for high-voltage high-power full-bridge zero-voltage switching PWM converter,”
in Proc. Appl. Power Electron. Conf., 1990, pp. 275–284.
[2]
I. O. Lee and G. W. Moon, “Phase-shifted PWM converter with a wide ZVS range
and reduced circulating current,” IEEE Trans. Power Electron., vol. 28,
no. 2, pp. 908–919, Feb. 2013.
[3]
Y. S. Shin, S. S. Hong, D. J. Kim, D. S. Oh, and S. K. Han, “A new changeable
full bridge dc/dc converter for wide input voltage range,” in Proc. 8th Int.
Conf. Power Electron. ECCE Asia, May 2011, pp. 2328–2335.
[4]
P. K. Jain, W., Kang, H. Soin, and Y. Xi, “Analysis and design considerations of
a load and line independent zero voltage switching full bridge dc/dc converter
topology,” IEEE Trans. Power Electron., vol. 17, no. 5, pp. 649–657,
Sep. 2002.
[5]
I. O. Lee and G. W. Moon, “Soft-switching DC/DC converter with a full ZVS range
and reduced output filter for high-voltage application,” IEEE Trans. Power
Electron., vol. 28, no. 1, pp. 112–122, Jan. 2013.
