最近幾年來，隨著攜帶式裝置的使用不斷增加，無線功率傳輸技術逐漸吸引廣泛的關注。本篇論文提出了模糊控制頻率調變追蹤最大效率控制系統，為無線功率傳輸系統提供穩定的效率。透過參考線圈不對齊的數學模型和計算線圈參數得以改善該系統追踪無線功率傳輸之最大效率。本篇論文使用Labview，一個National Instruments的系統設計平台和可視化編程開發環境語言，編譯好程式後上傳至NImyRIO，並控制壓控制振盪器（VCO），來完成頻率調變模糊控制追蹤無線功率傳輸最大效率。在這個論文中將設計兩種控制器，一個是PID控制器，另一個是模糊控制器。這兩個控制器將設計人機介面（UI）以便即時監控接收電壓和追踪最大效率。 無線功率傳輸系統結構包含NImyRIO，PC端的人機介面，壓控制振盪器調變頻率，NMOSFET開關，與發射線圈和接收線圈。 無線功率傳輸系統的設計過程將從了解兩個平面螺旋線圈的配置開始，然後實現正確設計的控制器。在完成系統設置和設計控制器之後，模糊控制器與PID控制器將互相比較。最後兩個控制器比較的結果顯示，模糊控制器具有更好的接收電壓效率並且比PID控制器穩定。

Recently, the wireless power transfer(WPT) technology is attracting
attention widely because of the expanding use of portable devices. This
thesis present the steps in designing control systems for frequency tuning
method that provide a constant efficiency for WPT system. By considering
coils misalignment mathematical module and the coils parameters that improve
this system tracking the maximum efficiency. And using Labview, a
system-design platform and development environment for a visual programming
language from National Instruments, to program NImyRIO and adjust voltage
control oscillator(VCO), the frequency tuning method for tracking maximum
efficiency will accomplish by appropriately designed controllers. In this
thesis, there are two controller will be designed, one is PID controller and
the other is fuzzy controller. These two controllers with an user
interface(UI) can real-time monitoring the receive voltage and tracking the
maximum efficiency. The WPT structure contain a PC which control NImyRIO and
monitor the voltage feedback, a VCO for tuning frequency, an NMOSFET, a
transmit coil and a receive coil. The process of WPT system start with
understanding the configuration of two planar spiral coils, then implement
the properly designed controllers. After finishing the system setup and
designing controller, the performance of two controller will compare to each
other. The result from the comparison of two controllers shows that the
fuzzy controller has the better performance of receiving voltage and more
stable than PID controller.

Abstract in Chinese I
Abstract in English II
Contents IV
List of Figures VI
List of Tables VIII
1 Introduction 1
1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Problem Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2 Theory of wireless power transfer 7
2.1 Coil configuration and coil modeling . . . . . . . . . . . . . . . . . . . 7
2.1.1 Inductance modeling . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1.2 Parasitic capacitance modeling . . . . . . . . . . . . . . . . . . 9
2.1.3 Parasitic resistance modeling . . . . . . . . . . . . . . . . . . . . 9
2.1.4 Q-factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1.5 Coupling coefficient between two coupled coils . . . . . . . . . . 10
2.1.6 Coil Misalignment Model . . . . . . . . . . . . . . . . . . . . . . 11
2.2 The effect of frequency ω . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3 Control Strategies 20
3.1 Wireless Power Transfer Structure . . . . . . . . . . . . . . . . . . . . . 21
3.2 Fuzzy Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.3 PID controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4 Experiment and Simulation Result 27
4.1 Comparison of fuzzy control and PID control . . . . . . . . . . . . . . . 29
5 Conclusion 34
References 35
List of Figures 
1.1 Nikola Tesla operated an experiment of radio wave for power transmission. 3
1.2 (a)Super-lens [23]; (b)Bean array [22] . . . . . . . . . . . . . . . . . . . 4
1.3 Microwave-power helicopter. . . . . . . . . . . . . . . . . . . . . . . . . 5
1.4 Microwave-power helicopter. . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1 Geometrical architecture of circular-shaped resonators. . . . . . . . . . 7
2.2 Resonator lumped model. . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.3 Equivalent circuital model of an inductive link. . . . . . . . . . . . . . . 12
2.4 (a)Lateral Misalignment; (b)Angular Misalignment . . . . . . . . . . . 14
2.5 Short solenoid. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.6 Planar spiral coil. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.7 The effect of frequency. . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.8 Equivalent circuit lumped model. . . . . . . . . . . . . . . . . . . . . . 17
3.1 Wireless power transfer structure. . . . . . . . . . . . . . . . . . . . . . 21
3.2 Fuzzy controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.3 Input f membership function. . . . . . . . . . . . . . . . . . . . . . . . 23
3.4 Input Verror membership function. . . . . . . . . . . . . . . . . . . . . . 24
3.5 Output u membership function. . . . . . . . . . . . . . . . . . . . . . . 24
3.6 Fuzzy Test system by Labview. . . . . . . . . . . . . . . . . . . . . . . 25
3.7 Fuzzy controller block diagram. . . . . . . . . . . . . . . . . . . . . . . 25
3.8 PID controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.9 PID controller block diagram. . . . . . . . . . . . . . . . . . . . . . . . 26
4.1 Wireless power system setup. . . . . . . . . . . . . . . . . . . . . . . . 27
4.2 Wireless power system prototype. . . . . . . . . . . . . . . . . . . . . . 28
4.3 Resonant frequency at different distance. . . . . . . . . . . . . . . . . . 29
4.4 Relation between distance and efficiency . . . . . . . . . . . . . . . . . 30
4.5 Fuzzy controller tuned efficiency. . . . . . . . . . . . . . . . . . . . . . 30
4.6 Fuzzy controller user interface. . . . . . . . . . . . . . . . . . . . . . . . 31
4.7 PID controller tuned efficiency. . . . . . . . . . . . . . . . . . . . . . . 31
4.8 PID controller user interface. . . . . . . . . . . . . . . . . . . . . . . . . 32
4.9 Comparison of fuzzy control and PID control. . . . . . . . . . . . . . . 32
4.10 (a)Fuzzy control on oscilloscope; (b)PID control on oscilloscope . . . . 33
List of Tables 
2.1 Parameters of planar spiral . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.1 Fuzzy rule table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

[1] G. Lipworth, J. Ensworth, K. Seetharam, D. Huang, J. S. Lee, P. Schmalenberg,
T. Nomura, M. S. Reynolds, D. R. Smith, and Y. Urzhumov, “Magnetic metamaterial
superlens for increased range wireless power transfer,” Scienti c reports,
vol. 4, p. 3642, 2014.
[2] N. Shinohara, “Beam control technologies with a high-efficiency phased array for
microwave power transmission in japan,” Proceedings of the IEEE, vol. 101, no. 6,
pp. 1448–1463, 2013.
[3] Wireless power reader technologies. [Online]. Available: http://www.appannie.com
[4] S. A. Ahson and M. Ilyas, RFID handbook: applications, technology, security, and
privacy. CRC press, 2008.
[5] G. A. Covic and J. T. Boys, “Inductive power transfer,” Proceedings of the IEEE,
vol. 101, no. 6, pp. 1276–1289, 2013.
[6] I. Systems Control Technology, “Roadway powered electric vehicle project track
construction and testing program phase 3d,” Tech. Rep., 1994.
[7] Smartpower wireless power. Smartpower Technology Global Company. [Online].
Available: http://www.smartpowertec.com
[8] K. Fotopoulou and B. W. Flynn, “Wireless power transfer in loosely coupled links:
Coil misalignment model,” IEEE Transactions on Magnetics, vol. 47, no. 2, pp.
416–430, 2011.
[9] M. Soma, D. C. Galbraith, and R. L. White, “Radio-frequency coils in implantable
devices: Misalignment analysis and design procedure,” IEEE transactions on
biomedical engineering, no. 4, pp. 276–282, 1987.
[10] H. Li, K. Wang, L. Huang, W. Chen, and X. Yang, “Dynamic modeling based on
coupled modes for wireless power transfer systems,” IEEE Transactions on Power
Electronics, vol. 30, no. 11, pp. 6245–6253, 2015.
[11] G. Vandevoorde and R. Puers, “Wireless energy transfer for stand-alone systems:
a comparison between low and high power applicability,” Sensors and Actuators
A: Physical, vol. 92, no. 1, pp. 305–311, 2001.
[12] F. W. Grover, Inductance calculations: working formulas and tables. Courier
Corporation, 2004.
[13] F. E. Terman et al., “Radio engineer’s handbook,” 1943.
[14] F. Flack, E. James, and D. Schlapp, “Mutual inductance of air-cored coils: Effect
on design of radio-frequency coupled implants,” Medical and Biological Engineering
and Computing, vol. 9, no. 2, pp. 79–85, 1971.
[15] E. S. Hochmair, “System optimization for improved accuracy in transcutaneous
signal and power transmission,” IEEE Transactions on biomedical engineering,
no. 2, pp. 177–186, 1984.
[16] A. P. Sample, B. H. Waters, S. T. Wisdom, and J. R. Smith, “Enabling seamless
wireless power delivery in dynamic environments,” Proceedings of the IEEE, vol.
101, no. 6, pp. 1343–1358, 2013.
[17] S. F. Pichorim and P. J. Abatti, “Design of coils for millimeter-and submillimetersized
biotelemetry,” IEEE Transactions on Biomedical Engineering, vol. 51, no. 8,
pp. 1487–1489, 2004.
[18] P. R. Troyk, “Injectable electronic identification, monitoring, and stimulation systems,”
Annual review of biomedical engineering, vol. 1, no. 1, pp. 177–209, 1999.
[19] C.-J. Chen, T.-H. Chu, C.-L. Lin, and Z.-C. Jou, “A study of loosely coupled
coils for wireless power transfer,” IEEE Transactions on Circuits and Systems II:
Express Briefs, vol. 57, no. 7, pp. 536–540, 2010.
[20] M. Zargham and P. G. Gulak, “Maximum achievable efficiency in near-field coupled
power-transfer systems,” IEEE Transactions on Biomedical Circuits and Systems,
vol. 6, no. 3, pp. 228–245, 2012.
[21] K. Koh, T. Beh, T. Imura, and Y. Hori, “Multi-receiver and repeater wireless power
transfer via magnetic resonance couplingximpedance matching and power division
utilizing impedance inverter,” in Electrical Machines and Systems (ICEMS), 2012
15th International Conference on. IEEE, 2012, pp. 1–6.
[22] M. Ettorre and A. Grbic, “A transponder-based, nonradiative wireless power transfer,”
IEEE Antennas and Wireless Propagation Letters, vol. 11, pp. 1150–1153,
2012.
[23] S. Y. R. Hui, W. Zhong, and C. K. Lee, “A critical review of recent progress
in mid-range wireless power transfer,” IEEE Transactions on Power Electronics,
vol. 29, no. 9, pp. 4500–4511, 2014.
[24] D. Huang, Y. Urzhumov, D. R. Smith, K. Hoo Teo, and J. Zhang, “Magnetic
superlens-enhanced inductive coupling for wireless power transfer,” Journal of Ap-
plied Physics, vol. 111, no. 6, p. 064902, 2012.
[25] A. P. Sample, D. T. Meyer, and J. R. Smith, “Analysis, experimental results, and
range adaptation of magnetically coupled resonators for wireless power transfer,”
IEEE Transactions on Industrial Electronics, vol. 58, no. 2, pp. 544–554, 2011.
[26] J. Park, Y. Tak, Y. Kim, Y. Kim, and S. Nam, “Investigation of adaptive matching
methods for near-field wireless power transfer,” IEEE Transactions on Antennas
and Propagation, vol. 59, no. 5, pp. 1769–1773, 2011.
[27] T. Imura, H. Okabe, and Y. Hori, “Basic experimental study on helical antennas of
wireless power transfer for electric vehicles by using magnetic resonant couplings,”
in Vehicle Power and Propulsion Conference, 2009. VPPC'09. IEEE. IEEE, 2009,
pp. 936–940.
[28] W. C. Brown, “The history of power transmission by radio waves,” IEEE Trans-
actions on Microwave Theory and Techniques, vol. 32, no. 9, pp. 1230–1242, 1984.
[29] Z. Popovic, “Cut the cord: Low-power far-field wireless powering,” IEEE Mi-
crowave Magazine, vol. 14, no. 2, pp. 55–62, 2013.
[30] S. S. Mohan, M. del Mar Hershenson, S. P. Boyd, and T. H. Lee, “Simple accurate
expressions for planar spiral inductances,” IEEE Journal of solid-state circuits,
vol. 34, no. 10, pp. 1419–1424, 1999.
[31] S. Raju, R. Wu, M. Chan, and C. P. Yue, “Modeling of mutual coupling between
planar inductors in wireless power applications,” IEEE Transactions on Power
Electronics, vol. 29, no. 1, pp. 481–490, 2014.
[32] M. Zolog, D. Pitica, and O. Pop, “Characterization of spiral planar inductors built
on printed circuit boards,” in Electronics Technology, 30th International Spring
Seminar on. IEEE, 2007, pp. 308–313.
[33] A. K. RamRakhyani, S. Mirabbasi, and M. Chiao, “Design and optimization of
resonance-based efficient wireless power delivery systems for biomedical implants,”
IEEE Transactions on Biomedical Circuits and Systems, vol. 5, no. 1, pp. 48–63,
2011.
[34] L. J. Paulsen, “Control of wireless power transfer systems for marine applications,”
Master’s thesis, NTNU, 2016.
[35] K. Van Schuylenbergh and R. Puers, Inductive powering: basic theory and appli-
cation to biomedical systems. Springer Science & Business Media, 2009.
[36] D. C. Galbraith, M. Soma, and R. L. White, “A wide-band efficient inductive transdennal
power and data link with coupling insensitive gain,” IEEE Transactions on
Biomedical Engineering, no. 4, pp. 265–275, 1987.
[37] S. Ramo, J. R. Whinnery, and T. Van Duzer, Fields and waves in communication
electronics. John Wiley & Sons, 2008.
[38] K. Yamaguchi, T. Hirata, and I. Hodaka, “High power wireless power transfer
driven by square wave inputs,” Genetic and Evolutionary Computing, p. 341, 2016.
[39] J. D. Heebl, E. M. Thomas, R. P. Penno, and A. Grbic, “Comprehensive analysis
and measurement of frequency-tuned and impedance-tuned wireless non-radiative
power-transfer systems,” IEEE Antennas and Propagation Magazine, vol. 56, no. 5,
pp. 131–148, 2014.