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Adjusting the frequency of an autonomous push–pull converter for wireless power transfer through a voltage-controlled variable capacitor structure

Published online by Cambridge University Press:  16 February 2017

Jianlong Tian*
Affiliation:
Electrical and Computer Engineering, University of Auckland, 368 Khyber Pass Road, Newmarket, Auckland 1023, New Zealand
Patrick Hu
Affiliation:
Electrical and Computer Engineering, University of Auckland, 38 Princes St, Auckland Central, Auckland, New Zealand
*
Corresponding author: J. Tian Email: jtia983@aucklanduni.ac.nz
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Abstract

This paper proposes a Voltage-controlled Variable Capacitor Structure (VVCS) to adjust the frequency of an autonomous push–pull converter. Unlike traditional switch mode capacitors or inductors where active switches are used, the equivalent capacitance of the VVCS varies with the on/off periods of a diode controlled by a DC voltage. The frequency of the autonomous push–pull converter can be controlled by this DC voltage when the VVCS is used as a variable resonant capacitor. As no active switching is involved in the VVCS, the circuit operates more smoothly than its switch mode counterpart so as to provide a simple way to adjust the operating frequency of the autonomous push–pull converter for high frequency and low electro magnetic interference operations. Mathematical model is developed for the relationship between the equivalent capacitance of the VVCS and the DC control voltage, and is verified by experimental results at more than 900 kHz with an approximately 12 W inductive power transfer system.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2017 

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References

[1] Covic, G.A.; Boys, J.T.; Tam, A.M.W.; Peng, J.C.H.: Self tuning pick-ups for inductive power transfer, in IEEE Power Electronics Specialists Conf., 2008. PESC 2008, 2008, 34893494.Google Scholar
[2] James, J.; Boys, J.; Covic, G.: A variable inductor based tuning method for ICPT pickups, in The 7th Int. Power Engineering Conf., 2005. IPEC 2005, 2005, 2, 11421146.Google Scholar
[3] Si, P.; Hu, A.P.; Malpas, S.; Budgett, D.: Switching frequency analysis of dynamically detuned ICPT power pick-ups, in Int. Conf. on Power System Technology, 2006. PowerCon 2006, 2006, 18.Google Scholar
[4] Hsu, J.U.W.; Hu, A.P.: Determining the variable inductance range for an LCL wireless power pick-up, in IEEE Conf. on Electron Devices and Solid-State Circuits, 2007. EDSSC 2007, 2007, 489492.Google Scholar
[5] Si, P.; Hu, A.P.; Malpas, S.; Budgett, D.: A frequency control method for regulating wireless power to implantable devices, IEEE Trans. Biomed. Circuits Syst, 2008, 2, 2229.Google Scholar
[6] Hamill, D.C.; Bina, M.T.: The bootstrap variable inductance and its applications in AC power systems, in 14th Annual Applied Power Electronics Conf. and Exposition. APEC ‘99, 1999, 2, 896902.Google Scholar
[7] Al-Kuran, S.: GaAs switched capacitor voltage converter, in WESCON/96, 1996, 130134.Google Scholar
[8] Wong, C.S.; Loo, K.H.; Lai, Y.M.; Chow, M.H.L.; Tse, C.K.: Accurate capacitive current balancing in multistring LED lighting systems based on switched-capacitor-controlled LCC resonant network. IEEE Trans. Power Electron., PP (2016), 1.Google Scholar
[9] Gu, W.-J.; Harada, K.: A new method to regulate resonant converters. IEEE Trans. Power Electron., 3 (1988), 430439.Google Scholar
[10] Gu, W.-J.; Harada, K.: A circuit model for the class E resonant DC-DC converter regulated at a fixed switching frequency. IEEE Trans. Power Electron., 7 (1992), 99110.Google Scholar
[11] Harada, K.; Gu, W.-J.: Steady state analysis of Class E resonant DC-DC converter regulated under fixed switching frequency, 19th Annual IEEE in Power Electron. Specialists Conf. PESC'88 Record, 1988, 38.Google Scholar
[12] Harada, K.; Gu, W.J.; Murata, K.: Controlled resonant converters with switching frequency fixed, IEEE in Power Electronics Specialists Conf., 1987, 431438.Google Scholar
[13] Perez-Nicoli, P.; Castro, P.; Silveira, F.: A series-parallel switched capacitor step-up DC-DC converter and its gate-control circuits for over the supply rail switches, in 2014 IEEE 5th Latin American Symp. on Circuits and Systems (LASCAS), 2014, 14.Google Scholar
[14] Aghdam, S.R.; Babaei, E.; Zadeh, S.G.: Improvement the performance of switched-inductor Z-source inverter, in Industrial Electronics Society, IECON 2013 – IEEE 39th Annual Conf., 2013, 876881.Google Scholar
[15] Fang Lin, L.; Hong, Y.: Switched inductor two-quadrant DC/DC converter with fuzzy logic control, in Proc. of the IEEE 1999 Int. Conf. on Power Electronics and Drive Systems. PEDS ‘99, 1999, 2, 773778.Google Scholar
[16] Hu, Y.; Li, K.; Yin, Z., Ioinovici, A.: Switched-inductor-based non-isolated large conversion ratio, low components count DC-DC regulators, in 2015 IEEE Energy Conversion Congress and Exposition (ECCE), 2015, 13981405.Google Scholar
[17] Ismeil, M.A.; Kouzou, A.; Kennel, R.; Ibrahim, A.A.; Orabi, M., Ahmed, M.E.: Modeling of non-ideal improved Switched Inductor (SL) Z-source inverter, in Int. Aegean Conf. on Electrical Machines and Power Electronics and Electromotion, Joint Conf., 2011, 472477.Google Scholar
[18] Kossel, M.; Morf, T.; Buchmann, P.; Schmatz, M.L.; Menolfi, C.; Toifl, T.: Switched Inductor with wide tuning range and small inductance step sizes. IEEE Microw. Wireless Compon. Lett., 19 (2009), 515517.Google Scholar
[19] Liu, H.; Li, F.: A novel high step-up converter with a quasi-active switched-inductor structure for renewable energy systems. IEEE Trans. Power Electron., 31 (2016), 50305039.Google Scholar
[20] Mousa, M.; Ahmed, M.E.; Orabi, M.: New converter circuitry for high v applications using switched inductor multilevel converter, in 2011 IEEE 33rd Int. Telecommunications Energy Conf. (INTELEC), 2011, 18.Google Scholar
[21] Nguyen, M.K.; Le, T.V.; Park, S.J.; Lim, Y.C.; Yoo, J.Y.: Class of high boost inverters based on switched-inductor structure. IET Power Electron., 8 (2015), 750759.Google Scholar
[22] Tang, Y.; Fu, D.; Wang, T.; Xu, Z.: Hybrid switched-inductor converters for high step-up conversion. IEEE Trans. Ind. Electron., 62 (2015), 14801490.Google Scholar
[23] Tian, J., Hu, A.P.: Adjusting the frequency of an autonomous push pull converter for wireless power transfer by varying the equivalent resonant capacitance through balanced DC voltage control, in 2015 IEEE PELS Workshop on Emerging Technologies: Wireless Power (WoW), 2015, 14.Google Scholar
[24] Hu, A.P.: Selected resonant converters for IPT power supplies. PhD thesis, The University of Auckland, ResearchSpace@ Auckland, 2001.Google Scholar
[25] Si, P.; Hu, A.P.; Budgett, D.; Malpas, S.; Yang, J.; Gao, J.: Stabilizing the operating frequency of a resonant converter for wireless power transfer to implantable biomedical sensors, in Proc. 1st Int. Conf. Sensing Technology, 2005, 477482.Google Scholar