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Analysis Design and Experimental Verification of a Two-Switch Forward Converter

Virot Wuti(1*), Chanin Bunlaksananusorn(2)

(1) Faculty of engineering, King Mungkut's Institute of Technology Ladkrabang (KMITL), Thailand
(2) Faculty of engineering, King Mungkut's Institute of Technology Ladkrabang (KMITL), Thailand
(*) Corresponding author



A forward converter is an isolated DC-DC converter widely used in switching power supplies with output power ratings ranging from 50W to 400W. The conventional forward converter requires a transformer with a tertiary winding to assist in magnetic core reset and subjects its power switch to a high voltage at turn-off. These shortcomings are eliminated in the two-switch forward converter. This paper presents analysis, design and experimental verification of a two-switch forward converter. First, the converter operation is analyzed, enabling its key equations and important waveforms to be established. Then, the converter design, including both the power circuit and feedback controller, is illustrated in detail. Finally, experimental results from the prototype circuit are presented to confirm the validity of the analysis and design.
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Analysis; Design; Control; Two-Switch Forward Converter

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F. D Tan, The forward converter from the classic to the contemporary, Applied Power Electronic Conference and Exposition (APEC), vol. 2, 2002, pp. 857-864.

B. Andreycak, Active clamp and reset technique enhances forward converter performance, Texas Instrument Inc., 2001.

C. D. Bridge, Clamp voltage analysis for RCD forward converters, Applied Power Electronic Conference and Exposition (APEC), vol. 2, 2000, pp. 959-965.

A. I. Pressman, K. Billings, and T. Morey, Switching Power Supply Design (McGraw-Hill Companies, 2009).

D. W. Hart, Power Electronics (McGraw-Hill Companies, 2011).

M. Chen, D. Xu, and M. Matsui, Study on magnetizing inductance of high frequency transformer in the two-transistor forward converter, Power Conversion Conf. Proceedings, vol. 2, April 2002, pp. 597-602.

B. Bell, Two-switch topology benefits forward and flyback power converters, EDN Magazine, September 2000, pp. 107-111.

E. Walker, Design review: a step-by-step approach to ac line-powered converters, Texas Instrument Inc., 2005.

T. Sutto, 2 Switch-forward current mode converter, On Semiconductor Application Notes, 2010, Publication order number: AND8373/D.

V.S.A.K Choragudi, Analysis and design of pulse-width modulated two-switch forward dc-dc converter for universal laptop adapter, Master Thesis, Wright State University, 2011.

P. Zuk and S. Havanur, Two-switch forward converter: operation FOM and mosfet selection guide, Vishay Siliconix Application Notes, 2014, Document number: 91616.

J. Xu, X. Cao, and Q. Luo, An improved two-transistor forward converer, International Conference on Power Electronics and Drive Systems (PEDS), July 1999, pp. 225-228.

M. Prudik and P. Vorel, Advantages of using two-switch forward converter for high-voltage applications, International Symposium on Power Electronics, Electrical Drive, Automation and Motion, June 2012, pp.326-330.

Data sheet ETD 44/22/15 cores and accessories, EPCOS, 2006.

Data sheet E 42/21/15 E cores and accessories, ERROXCUBE, 2008.

R.W. Erickson and D. Maksimovic, Fundamentals of Power Electronics, 2nd ed., (Kluwer Academic Publishers, 2001).

B. C. Kuo and F. Golnaraghi, Automatic Control Systems, 8th ed., (John Wiley & Sons, 2002).

R. D. Middlebook and S. Cuk, A general unified approach to modeling switching-converter power stages, INTERNATIONAL JOURNAL OF ELECTRONICS, vol. 42, June 1977, pp. 521-550.

P. Chrin, S. Trakuldit, S. Polmai, and C. Bunlaksananusorn, Improvement of output dynamic performance of an average current mode controlled Buck converter with a parallel controller, International Power Electronics Conference (IPEC), June 2010, pp. 1916-1922.

V. Wuti, T. Kerdpol, and C. Bunlaksananusorn, Feedback compensator design for a two-switch forward converter, IEEE International Conference on Electron Devices And Solid State Circuits, 2012, pp. 1-4.


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