DESIGN AND IMPLEMENTATION OF SOFT SWITCHED HIGH GAIN CURRENT FED FULL

BRIDGE DC-DC CONVERTER FOR FUEL CELL APPLICATIONS

D Elangovan Asst.Prof (Senior)

Dr.R.Saravanakumar Professor

Siddhartha NigamUG Student

Dr.D.P.KothariProfessor

School of Electrical Engineering , VIT University ,Vellore

Members

BACKGROUND TO THE RESEARCH

Recently, green power concept has potentially attracted the attention of researchers, industries as well as common men.

With the concept of smart grid, smart meters and smart buildings, alternative energy sources are getting increasingly importance

The alternative energy sources cannot be used as such as they provide unregulated electric power.

A power electronics interface is required to convert power from alternative energy sources into usable power for several applications including grid-interface, vehicles, residential or standalone load applications

BACKGROUND TO THE RESEARCH

Among fuel cells, wind & solar power, fuel cells are considered a potential and capable candidate energy source as they can provide continuous power in all seasons as long as the continuity of fuel supply is maintained.

Fuel cells are regarded as one option for a more environmentally friendly energy market in the future.[1]

The main issues in power generation using fuel cell: High efficiency during load operation Large step-up ratio Low input ripple current to increase the fuel cell

lifetime.Challenges:

Design and interfacing an efficient and low cost power converter.

Literature Review

Boost Converter-The boost converter is one of the most important non isolated converter A conventional boost converters are able to

achieve high step-up voltage gain in heavy duty Vo = Vdc / (1-D) where D is the duty ratio =

Ton / T

With a very high duty ratio, the output rectifier conducts for only a very short time during each switching cycle

Very narrow turnoff pulses Serious output diode reverse

recovery problem The switch-off loss due to the

rectifier diode will degrade the efficiency

Literature Review

Ref.no Journal Topic Strengths weaknesses

[ 2 ] IEEE Trans. Power Electron, Mar.2008

Voltage multiplier cells applied to non-isolated DC–DC converters

High voltage gain without high duty ratio

diode reverse recovery issues

Requires additional resonant inductors to cope with the diode reverse recovery problem

[3] IEEE Trans. Power Electron, Jul.2007

Interleaved boost converter for PFC front end,”

[4] IEEE Int. Symp. Power Electron. (ISIE), Jun. 2003

An interleaved boost DC–DC converter with large conversion ratio

Topology : Interleaved boost – Non isolatedLiterature Review

Ref.No Journal Topic Strengths weaknesses

[5] IEEE Trans. Power Electron, Jul.2008

“A family of interleaved DC–DC converters deduced from a basic cell with coupled inductors,”

Interleaved converter is an attractive solution for high voltage gain applications, but it is complex and high cost (two sets of power devices, magnetic core & control circuit)

diode reverse recovery affects the overall efficiency

coupled inductor turns ratio that allows to boost the output voltage without high duty ratio

.

Leakage inductance of the coupled inductor affects the efficiency

[6] IEEE Vehicle Power Propulsion Conf. (VPPC), Sep.2007

A novel high efficiency high power interleaved coupled-inductor boost DC–DC converter for hybrid and fuel cell electric vehicle

[7] IEEE Trans. Ind. Electron,Feb. 2007

High-efficiency DC–DC converter with high voltage gain and reduced switch stress,

Topology : Coupled Inductor

Ref.No Journal Topic Strengths weaknesses

[ 11 ] IEEE Trans. Power Electron, Jan.2003

“High-efficiency, high step-ip DC–DC converters,

Rectifier diode turnoff current is limited by leakage inductance of the coupled inductor itself.

Additional clamping circuit is necessary to circulate leakage energy

[10] IEE Proc. Electr. Power Appl, Mar. 2004

“Novel high-efficiency step-up converter

[9] IEE Proc. Electr. Power Appl, Jul. 2005

“High-efficiency DC/DC converter with high voltage gain,

Topology : Coupled Inductor

Ref.no Journal Topic Strengths weaknesses

[ 13 ] IEEE Trans. Power Electron, Nov.2011

High Step-Up Ratio Flyback Converter With Active Clamp and Voltage Multiplier

High voltage gain without high duty ratio

diode reverse recovery issues

Combines Isolation with soft commutation

Voltage stress across the rectifier diode

Single winding carries a current

Operates in discontinuous mode

High off state voltage

core utilization

[15] Proc. IEEE Appl. Power Electron, Jul.2006

A low power topology derived from flyback with active clamp based on a very simple transformer

[17] IEEE Trans. Power Electron, Nov.2005

Analysis, design and implementation of an active clamp flyback converter

Topology : Flyback Converter

Ref.no Journal Topic Strengths weaknesses

[ 18 ] ELSEVIERInternational Journal of hydrogen energy 3 4 ( 2 0 0 9)

Interleaved soft-switched active-clamped L–L type current-fed half-bridge DC–DC converter for fuel cell applications

High voltage gain without high duty ratio

Justified Current fed topology is best for fuel cell application

High efficiency compared to other topologies

Output diode suffers from reverse recovery problem.

The isolation transformer turns ration is high

[19] IEEE Trans. Inds Electron, Jan 2012

Analysis, Design and Experimental Results of Wide Range ZVS Active-Clamped L-L Type Current-Fed DC/DC Converter for Fuel Cells to Utility Interface

[20] IEEE Trans ENERGY CONVERSIONJun. 2007

Fuel Cell Generation System With a New Active Clamping Current-Fed Half-Bridge Converter

Topology : Half bridge DC-DC Converter

Filling knowledge gap

Ref.no Journal Topic Strengths weaknesses

[ 22 ] IEEE2012

Control Design of Current-fed Full-bridge Isolated Dc/Dc Converter with Active-clamp

High Power compared with half bridge

High efficieny.

Output diode suffers from reverse recovery problem.

The isolation transformer turns ration is high

[23] IEEE Trans. Power Electr, Jan 2008

Current-fed Full-bridge Boost Converter with Zero Current Switching for High Voltage Applications

[24] IEEE Trans. Power Electr, Mar 2007

Analysis & Implementation of a High Efficiency, Interleaved Current-Fed Full Bridge Converter for Fuel Cell System

Topology : Fullbridge DC-DC Converter

Conclusion High voltage gain possible without high duty ratio Leakage inductance energy is recycled using Clamping circuits

thereby reducing the switch voltage stress

Compact and Cost-effective power supplies with low losses and high efficiency are major concern.

Our work focuses on reducing the size of power supplies and maximizing the power density by introducing new Dc-Dc converter

Proposed Converter

STEADY STATE ANALYSIS

OF THE PROPOSED

CONVERTER

Modes of operationMode-1

At t=t2, iLk=0 and thus

Mode-2

Mode-3

Mode-4

Mode-5

Mode-6

Equivalent circuits

Theoretical Waveforms

Half-Wave Cockroft-Walton Voltage Multiplier

OPTIMAL DESIGN CALCULATIONS

REFERENCE:-Ioannis C. Kobougias and Emmanuel C. Tatakis (2010), “Optimal Design of a Half-Wave Cockcroft–Walton Voltage Multiplier With Minimum Total Capacitance”. IEEE Trans. Power Electron., VOL. 25, NO. 9.

• The C-W VM circuit topology is an easy and an efficient way of achieving a high voltage conversion ratio.

• Due to the AC impedance of the capacitors, there is a voltage drop and a peak to peak ripple when the circuit is fully loaded.

• Moreover, most of the C-W VM circuits are designed with equal capacitances.

Case 1: C2i = C2i−1 = C (the classical case where all capacitors are equal)

Case 2: C1=C2 = 2C and C2i = C2i−1 = C for i = 1 (case often found in the bibliography)

Case 3: C2i = C2i−1 = (n + 1 − i)C

Case 4: C2i = (n + 1 − i)C and C2i−1 = (n + 1 − i)2C

i : number of every stage C : capacitance of the last stage, defined as base capacitance.

Choice of capacitance

• Thus, an optimized H-W C-W VM circuit design is chosen.• There are 4 optimal design cases present for the V-M circuit present

Case 3 can be characterized as the best choice among the four cases for an optimizeddesign of a H-W C-W VM, because it gives the desired output voltage with a nearly optimum number of stages, a relatively small voltage ripple and the minimum total capacitance.

Simulation of the Proposed Converter

Parameter Values

Input voltage 30V

Transformer primary turns 25

Transformer secondary turns 25

Output voltage 240V

Switching Frequency 100KhZ

Simulation Parameters

Input & Output Voltage

Transformer Primary & Secondary Voltage

ZCS

HARDWARE IMPLEMENTATION

Hardware Model

High Frequency Transformer

Source

CSI

Voltage Multiplier

Step Down Transformer

Rectifier with filter

Microcontroller and driver setup

Conclusion

• The size of the transformer gets reduced and the

• Efficiency of the proposed method is more compared to the conventional

method

References

[1] Prasanna U R, Member, IEEE, and Akshay K Rathore, Member, IEEE ,” Analysis and Design of Zero-Voltage-Switching Current-Fed Isolated Full-Bridge Dc/Dc Converter” IEEE PEDS 2011, Singapore, 5 - 8 December 2011

Interleaved boost – Non isolated

[2] M. Prudente, L. L. Pfitscher, G. Emmendoerfer, E. F. Romaneli, and R. Gules, “Voltage multiplier cells applied to non-isolated DC–DC converters,” IEEE Trans. Power Electron., vol. 23, no. 2, pp. 871–887, Mar.2008

[3] Y. Jang and M. M. Jovanovic, “Interleaved boost converter with intrinsic voltage-doubler characteristic for universal-line PFC front end,” IEEE Trans. Power Electron., vol. 22, no. 4, pp. 1394–1401, Jul.2007.

[4] R. Gules, L. L. Pfitscher, and L. C. Franco, “An interleaved boost DC–DC converter with large conversion ratio,” in Proc. IEEE Int. Symp. Power Electron. (ISIE), Jun. 2003, vol. 1, pp. 411–416

References- Coupled Inductor

[5] W. Li and X. He, “A family of interleaved DC–DC converters deduced from a basic cell with winding-cross-coupled inductors,” IEEE Trans.Power Electron., vol. 23, no. 4, pp. 1791–1801, Jul. 2008.

[6] S.M. Dwari and L. Parsa, “A novel high efficiency high power interleaved coupled-inductor boost DC–DC converter for hybrid and fuel cell electric vehicle,” in Proc. IEEE Vehicle Power Propulsion Conf. (VPPC), Sep.2007, pp. 399–404

[7] R. J. Wai, C. Y. Lin, R. Y. Duan, and Y. R. Chang, “High-efficiency DC–DC converter with high voltage gain and reduced switch stress,” IEEE Trans. Ind. Electron., vol. 54, no. 1, pp. 354–364, Feb. 2007.

[8] T. J. Liang and K. C. Tseng, “Analysis of integrated boost-flyback step-up converter,” IEE Proc. Electr. Power Appl., vol. 152, no. 2, pp. 217–225,Mar. 2005.

References- Coupled Inductor

[9] R. J. Wai and R. Y. Duan, “High-efficiency DC/DC converter with high voltage gain,” IEE Proc. Electr. Power Appl., vol. 152, no. 4, pp. 793–802, Jul. 2005

[10] T. J. Liang and K. C. Tseng, “Novel high-efficiency step-up converter,”IEE Proc. Electr. Power Appl., vol. 151, no. 2, pp. 182–190, Mar. 2004.

[11] Q. Zhao and F. C. Lee, “High-efficiency, high step-ip DC–DC converters,”IEEE Trans. Power Electron., vol. 18, no. 1, pp. 65–73, Jan. 2003.

References- Flyback

[12] A. Bakkali, P. Alou, J. A. Oliver, and J. A. Cobos, “Average modeling and analysis of a flyback with active clamp topology based on a very simple transformer,” in Proc. IEEE Appl. Power Electron. Conf. (APEC), 2007,pp. 500–506

[13] Giorgio Spiazzi, , Paolo Mattavelli, and Alessandro Costabeber “High Step-Up Ratio Flyback Converter With Active Clamp and Voltage Multiplier” IEEE Trans.on power Electronics,VOL. 26, NO. 11, NOVEMBER 2011

References1. B.R.Lin, K.Huang, and D.Wang, (2005) “Analysis and Implementation of Full

Bridge Converter with Current Doubler Rectifier ”, in IEEE Proceedings Electric PowerApplications,Vol.152,No.5, pp.1193–1202.

2. Juergen Biela, Member, IEEE, Owe Badstuebner, Student Member, IEEE, and JohannW. Kolar, Senior Member, IEEE (2009),“Impact of Power Density Maximization on Efficiency of DC–DC Converter Systems” , IEEE Ttransactions on Power electronics, Vol. 24, No. 1.

3. Tereň, A., Feňo, I., Špánik, P (2001), “DC/DC Converters with Soft (ZVS) Switching.” In Conf. Proc. ELEKTRO 2001, section -Electrical Engineering. Zilina, pp. 82-90,

4. Y. Jiang, Z. Chen, J. Pan, X.I Zhao, and P. Lee (2008) , “A novel phase-shift full-bridge converter with voltage-doubler and decoupling integrated magnetics in PV system” IEEE-Vol. 56, No. 3.

5. Hyun-Lark Do (2010), “Soft switching dc-dc converter with high voltage gain”, IEEE Trans. Power Electron., VOL. 25. NO.5.

References6. Ioannis C. Kobougias and Emmanuel C. Tatakis (2010), “Optimal Design of a

Half-Wave Cockcroft–Walton Voltage Multiplier With Minimum Total Capacitance”. IEEE Trans. Power Electron., VOL. 25, NO. 9.

7. M. Prudente, L. L. Pfitscher, G. Emmendoerfer, E. F. Romaneli, and R. Gules (2008), “Voltage multiplier cells applied to non-isolated DC-DC converters,” IEEE Trans. Power Electron., vol. 23, no. 2, pp. 871–887.

8. J. M. Kwon and B. H. Kwon (2009), “High step-up active-clamp converter with input-current doubler and output-voltage doubler for fuel cell power systems,” IEEE Trans. Power Electron., vol. 24, no. 1, pp. 108–115.

9. Y. Hsieh, T.Hsueh, and H.Yen (2009), “An Interleaved boost converter with zero-voltage transition, “ IEEE Trans. Power Electron., Vol.24, NO.4, pp.973-978.

10.  D.Elangovan, P.D.Dharmesh, V.Ashwini (2010),“Power density maximisation of DC-DC converter” in IEEE proceedings IICPE, Vol.3, No.31, pp 31.

References- Flyback

[14] P. Alou, O. Garc´ıa, J. A. Cobos, J. Uceda, and M. Rasc´on, “Flyback with active clamp: A suitable topology for low power and very wide input voltage range applications,” in Proc. IEEE Appl. Power Electron. Conf. (APEC), 2002, pp. 242–248.

[15] P. Alou, A. Bakkali, I. Barbero, J. A. Cobos, and M. Rascon, “A low power topology derived from flyback with active clamp based on a very simple transformer,” in Proc. IEEE Appl. Power Electron. Conf. (APEC), 2006, pp. 627–632.

.

[16] N. P. Papanikolaou and E. C. Tatakis, “Active voltage clamp in flyback converters operating in CCM mode under wide load variation,” IEEE Trans. Ind. Electron., vol. 51, no. 3, pp. 632–640, Jun. 2004.

[17] B. R. Lin, H. K. Chiang, K. C. Chen, and D. Wang, “Analysis, design and implementation of an active clamp flyback converter,” in Proc. IEEE Power Electron. Drive Syst. (PEDS), 2005, pp. 424–429.

References- Halfbridge

[18] Akshay K. Rathore, Interleaved soft-switched active-clamped L–L type current-fed half-bridge DC–DC converter for fuel cell applications, International journal of hydrogen energy 3 4 ( 2 0 0 9 ) page no 9 8 0 2 – 9 8 1 5

[19] Akshay K. Rathore, Ashoka K. S. Bhat and Ramesh Oruganti “Analysis, Design and Experimental Results of Wide Range ZVS Active-Clamped L-L Type Current-Fed DC/DC Converter for Fuel Cells to Utility Interface “IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 59, NO. 1, JANUARY 2012

.

[20] Su-Jin Jang, Chung-Yuen Won, Byoung-Kuk Lee, “Fuel Cell Generation System With a New Active Clamping Current-Fed Half-Bridge Converter”, IEEE TRANSACTIONS ON ENERGY CONVERSION, VOL. 22, NO. 2, JUNE 2007

[21] S.-K. Han, H.-K. Youn, G.-W. Moon, M.-J. Youn, and Y.-H. Kim, “A new active clamping zero-voltage switching PWM current-fed half-bridge converter,” IEEE Trans. Ind. Electron., vol. 20, no. 6, pp. 1271–1279, Nov.2005.

References- Full bridge

[22] Prasanna UR, and Akshay K. Rathore, “Control Design of Current-fed Full-bridge Isolated Dc/Dc Converter with Active-clamp,” 978-1-4673-0158-9/12/$31.00 ©2012 IEEE

[23] Jiann-Fuh Chen, Ren-Yi Chen, and Tsorng-Juu Liang,” Study and Implementation of a Single-Stage Current-Fed Boost PFC Converter With ZCS for High Voltage Applications,” IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 23, NO. 1, JANUARY 2008

.

[24] Xin Kong, and Ashwin M. Khambadkone, “Analysis & Implementation of a High Efficiency, Interleaved Current-Fed Full Bridge Converter for Fuel Cell System”, IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 22, NO. 2, MARCH 2007

[25] G. Moschopoulos and P. Jain, “Single-stage ZVS PWM full-bridge converter,” IEEE Trans. Aerosp. Electron. Syst., vol. 39, no. 4, pp.1122–1133, Oct. 2003.

Thank you

Thank you…