The document describes the design of a wireless power transfer system using magnetic resonant coupling at 13.56MHz. It discusses different wireless power transfer techniques and applications. The author aims to design an improved system with high efficiency. The methodology includes designing a rectifier, H-bridge amplifier/oscillator, and coil antennas. Parameters for the designed antennas are presented. Simulations of the equivalent circuit, S-parameters, and power transfer efficiency are shown, demonstrating that the designed system achieves 78.18% efficiency at a coupling coefficient of 0.00429, significantly higher than two and three coil systems. The document concludes that an improved high-efficiency wireless power transfer system was achieved.

1. Design of Wireless Power
Transfer System via
Magnetic Resonant Coupling
at 13.56MHz
Ajay Kumar Sah
ajayshah2005@yahoo.com

2. Introduction
 Power
 Wireless Power transmission (WPT)
 Magnetic induction
 Resonant coupling
 Maximum power transfer
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3. Types Of WPT Techniques
On the basis of Distance:
Near field Mid field Far field
On the basis of mode of Coupling:
Inductive Capacitive Laser Microwave
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Application:
Implantable medical devices
smart cards and electric vehicle
mobile electronics
And many more..

4. Objective
To design an improved WPT system
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Block diagram of the system

5. Methodology
Rectifier Design I/p & o/p on PSPICE
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6. Methodology (Contd…)
Designed H Bridge
Amplifier/Oscillator
O/p of H-bridge
Amplifier/Oscillator
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7. Antenna System Design
7
The classic formula for single-layer inductance
(air core) is called Wheeler's formula is given
as:
Where,
L = inductance in micro Henries
N= number of turns of wire
R= radius of coil in cm
H= height of coil in cm Coil antenna
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8. Parameters of designed antenna
Coil
(antenna)
N(turns) R(cm) H(cm) L(uH) F(MHz) C(Pf)
Power 2 5 3.3 0.5 13.56 278.518
Tx 3 6 4.4 13 13.56 105.968
Rx 1.67 6 4.4 0.4 13.56 344.398
Load 1 3.7 2 0.1 13.56 1.377 nf
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9. Equivalent circuit of WPT system on ADS
9
Simulation set up of WPT system on ADS
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10. S-parameters of WPT System
10
Simulation result showing │S11│ and │S21│
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11. Power Transfer Efficiency of WPT System
11
Simulation set up for Power transfer efficiency
Power transfer efficiency of WPT system
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12. S parameters at variable k
12
Simulation result showing│S21│ at different k
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13. Comparison of all three WPT Systems
13
Simulation result showing │S11│ and │S21
Systems k │S11│ │S21│ Efficiency
2 coil system 0.5 0.929 0.367 13.46%
3 coil system 0.5 0.667 0.743 55.20%
Designed system 0.00429 0.012 0.884 78.18%
Table: Efficiency of Two coil, three coil and designed WPT SystemIOE – Graduate Conference , 29th November 2013, Central Campus , Pulchowk

14. Advantages
Wire-free
Does not need LOS
No radiation
Does not interfere with radio waves.
Very useful in biological implants.
Highly resonant strong coupling provides high
efficiency over distance.
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15. Conclusion
An improved WPT system was designed.
 Efficiency 78.18% at k=0.00429.
Significant improvements in terms of power-
transfer efficiency have been achieved.
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16. References
1. Sabuj Das Gupta, Md. Shahinur Islam, Kawser Md. Nuronnabi, Mohammad Sakib Hossain, Md. Zahid
Hasan - Design & Implementation of Cost Effective Wireless Power Transmission Model: GOOD BYE
Wires – published at: “International Journal of Scientific and Research Publications(IJSRP), Volume 2,
Issue 12, December 2012 Edition” .
2. William C. Brown, "The history of wireless power transmission," Solar Energy, vol.56, no.1, pp. 3-21,
January 1996
3. Sanghoon Cheon, Yong-Hae Kim, Seung-Youl Kang, Myung Lae Lee, and Taehyoung Zyung “Wireless
Energy Transfer System with Multiple Coils via Coupled Magnetic Resonances” ETRI Journal, Volume 34,
Number 4, August 2012
4. Mandip Jung Sibakoti, Professor Derin Sherman and Joey Hambleton “Wireless Power Transmission Using
Magnetic Resonance” Cornell College PHY312, December 2011.
5. Kurs, A. Karalis, R. Moffatt, J. D. Joannopoulos, P. Fisher, M. Soijacic, “Wireless Power Transfer via
Strongly Coupled Magnetic Resonances”, Massachusetts Institute of Technology, 2007 Science, Vol. 317.
no. 5834, pp. 83— 86, June 2007.
6. Kawamura, Atsuo, and Tae-Woong Kim. "Proposed Equivalent Circuit and Parameter Identification Method
for Electro-Magnetic Resonance Based Wireless Power Transfer.” April 2013.
7. Hoang, Huy, and Franklin Bien. "Maximizing Efficiency of Electromagnetic Resonance Wireless Power
Transmission Systems with Adaptive Circuits."Wireless Power Transfer–Principles and Engineering
Explorations: K. Y. Kim, ed., InTech, 2012. Print.
8. Jordan, Edward C., and K. G. Balmain. “Electromagnetic Waves and Radiating Systems”, Second ed. New
Dehli: Prentice-Hall of India, August 2006. Print.
9. Nilsson, James William., and Susan A. Riedel. “Electric Circuits”. Boston: Prentice Hall, January 2011.
Print.
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17. Thank You !
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