Current-Fed Dual-Bridge DC–DC Converter

Current-Fed Dual-Bridge DC–DC Converter

ABSTRACT

A new isolated current-fed pulse width modulation dc–dc converter—current-fed dual-bridge dc–dc converter—with small inductance and no dead time operation is presented and analyzed. The new topology has more than 3 smaller inductance than that of current-fed full-bridge converter, thus having faster transient response speed. Other characteristics include simple self-driven synchronous rectification, simple housekeeping power supply, and smaller output filter capacitance. Detailed analysis shows the proposed converter can have either lower voltage stress

on all primary side power switches or soft switching properties when different driving schemes are applied. A 48-V/125-W prototype dc–dc converter with dual output has been tested for the verification of the principles. Both simulations and experiments verify the feasibility and advantages of the new topology.

KEYWORDS

1.     Current-fed

2.     Dc–dc converter

3.     Dead time

4.     Dual-bridge

5.     Full-bridge

6.     Zero voltage switching (ZVS)

SOFTWARE: MATLAB/SIMULINK

CIRCUIT  DIAGRAM:

Fig. 1.Current-fed full-bridge dc–dc converter.

CONCLUSION:

A new topology, isolated current-fed dc–dc converter, characterized by small inductor and no dead time operation, is presented and analyzed. An experimental prototype with 48-V (36–62 V) input and dual outputs of 5 V/20 A and 12.5 V/2 A verifies the validity and merits of the new topology. It has small inductor (corresponding to faster transient response speed), and no RHP zero in its transfer characteristic. Its output ripple current is smaller in contrast to other current-fed topologies [1]–[10], and it has no start-up problem mentioned in [1] and [10]. The main limitations of the new topology are that six power switches are used, and that input voltage range should remain within 2:1 in order to maintain the no dead time property.

REFERENCES:

[1] L. Zhu, K. Wang, F. C. Lee, and J. S. Lai, “New start-up schemes for isolated full-bridge boost converters,” IEEE Trans. Power Electron., vol. 18, no. 4, pp. 946–951, Jul. 2003.

[2] V. Yakushev, V. Meleshin, and S. Fraidlin, “Full-bridge isolated current fed converter with active clamp,” in Proc. IEEE Appl. Power Electron. Conf., 1999, pp. 560–566.

[3] K. Wang, F. C. Lee, and J. Lai, “Operation principles of bi-directional full-bridge dc–dc converter with unified soft-switching scheme and soft-starting capability,” in Proc. IEEE PESC, 2000, pp. 111–118.

[4] P. Tenti, L. Rossetto, L. Malesani, R. Borgatti, and R. Stefani, “Single stage current-fed dc–dc converter with time-sharing control of output voltage and input current,” IEEE Trans. Power Electron., vol. 5, no. 4, pp. 389–397, Oct. 1990.

[5] R. Borgatti, R. Stefani, O. Bressan, F. Bicciato, P. Tenti, and L. Rossetto, “1 kW, 9 kV dc–dc converter module with time-sharing control of oupout voltage and input current,” IEEE Trans. Power Electron., vol.8, no. 4, pp. 606–614, Oct. 1993.