Novel Zero-Current Switching Current-Fed Half-Bridge Isolated Dc/Dc Converter for Fuel Cell Based Applications

ABSTRACT:

This paper presents a novel zero-current switching (ZCS) current-fed half-bridge isolated dc/dc converter. It is a potential topology for front-end dc/dc power conversion for fuel cell inverters. This proposed converter is unique, not reported in literature and provides a simple solution to switch turn-off problem with ZCS without increase in components count. This will lead to reduced size, lower cost and higher efficiency. Analysis, design and simulation results of the proposed converter are reported in this paper. A comparison with existing active-clamped ZVS current-fed half-bridge converter has been illustrated.

KEYWORDS:

1.      Zero-current switching

2.      Dc/Dc converter

3.      Current-fed

4.      Fuel cells

5.      High efficiency

SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Fig. 1. Conventional hard-switched current-fed half-bridge dc/dc converter

Fig. 2 Active-clamped ZVS current-fed half-bridge dc/dc converter

Fig. 3. Proposed ZCS current-fed half-bridge dc/dc converter.

 EXPECTED SIMULATION RESULTS:

Fig. 4. Zero-current switching of primary-side switches. The ripple frequency of input current I_in is 200 kHz, which

is same twice the switching frequency f_s. The transformer

Fig. 5. Zero-current turn-on of primary-side switches. V(S1) is voltage across switch S₁ and I(S1) is current through switch S₁. The current waveform is scaled for clarity.

Fig. 6. Current-waveforms through the secondary-side switches.

Fig. 7. Zero-current turn-on of secondary-side switches. V(Sr1) is voltage across switch S_r1 and I(Sr1) is current through switch S_\r1. The current waveform is scaled for clarity.

Fig. 8. Current waveforms through input inductors L₁ and L₂.

Fig. 9. . Input current (I_in) and transformer current I(Ls) waveforms.

REFERENCES:

[1] www.fossil.gov.in

[2] S. K. Mazumder, R. K. Burra, and K. Acharya, “A ripple-mitigating and energy-efficient fuel cell power-conditioning system,” IEEE Transactions on Power Electronics, vol. 22, 2007, pp. 1437-1452.

[3] Jin-Tae Kim, Byoung-Kuk Lee, Tae-Won Lee, Su-Jin Jang, Soo-Seok Kim, and Chung-Yuen Won, “An active clamping current-fed half bridge converter for fuel-cell generation systems,” in Proceedings 2004 IEEE Power Electronics Specialists Conference, pp. 4709-4714.

[4] S. Han, H. Yoon, G. Moon, M. Youn, Y. Kim, and K. Lee, “A new active-clamping zero-voltage switching PWM current-fed half-bridge converter,” IEEE Transactions on Power Electronics, vol. 20, pp 1271- 1279, 2006.

[5] S. J. Jang, C. Y. Won, B. K. Lee and J. Hur, “Fuel cell generation system with a new active clamping current-fed half-bridge converter,” IEEE Trans. on Energy Conversion, vol. 22, pp. 332-340, June 2007.