An Interference Isolation Method for Wireless Power and Signal Parallel Transmissions on CPT Systems

  • Zhou, Wei (College of Automation, Chongqing University) ;
  • Su, Yu-Gang (State Key Laboratory of Power Transmission Equipment and System Security and New Technology, Chongqing University) ;
  • Xie, Shi-Yun (College of Automation, Chongqing University) ;
  • Chen, Long (College of Automation, Chongqing University) ;
  • Dai, Xin (College of Automation, Chongqing University) ;
  • Zhao, Yu-Ming (College of Automation, Chongqing University)
  • Received : 2016.03.18
  • Accepted : 2016.11.14
  • Published : 2017.01.20


A novel interference isolation method is proposed by using several designed coils in capacitive power transfer systems as isolation impedances. For each designed coil, its stray parameters such as the inter-turn capacitance, coil resistance and capacitance between the coil and the core, etc. are taken into account. An equivalent circuit model of the designed coil is established. According to this equivalent circuit, the impedance characteristic of the coil is calculated. In addition, the maximum impedance point and the corresponding excitation frequency of the coil are obtained. Based on this analysis, six designed coils are adopted to isolate the interference from power delivery. The proposed method is verified through experiments with a power carrier frequency of 1MHz and a data carrier frequency of 8.7MHz. The power and data are transferred parrallelly with a data carrier attenuation lower than -5dB and a power attenuation on the sensing resistor higher than -45dB.


Supported by : National Natural Science Foundation of China, Chongqing International Science and Technology Cooperation Base


  1. J. H. Kim, B. Lee, J. Lee, S. Lee, C. Park, S. Jung, S. Lee, K. Yi, and J. Baek, "Development of 1-MW inductive power transfer system for a high-speed train," IEEE Trans. Ind. Electron., Vol. 62, No. 10, pp. 6242-6250, Oct. 2015.
  2. Y. Su, H. Zhang, Z. Wang, A. P. Hu, L. Chen, and Y. Sun, "Steady-state load identification method of inductive power transfer system based on switching capacitors," IEEE Trans. Power Electron., Vol. 30, No. 11, pp. 6349-6355, Nov. 2015.
  3. J. Huh, W. Lee, S. Choi, G. Cho, and C. Rim, "Frequency-domain circuit model and analysis of coupled magnetic resonance systems," Journal of Power Electronics, Vol. 13, No. 2, pp. 275-286, Mar. 2013.
  4. X. Dai, Y. Zou, and Y. Sun, "Uncertainty modeling and robust control for LCL resonant inductive power transfer system," Journal of Power Electronics, Vol. 13, No. 5, pp. 814-828, Sep. 2013.
  5. J. Dai and D. C. Ludois, "A survey of wireless power transfer and a critical comparison of inductive and capacitive coupling for small gap applications," IEEE Trans. Power Electron., Vol. 30, No. 11, pp. 6017-6029, Nov. 2015.
  6. L. Huang and A. P. Hu, "Defining the mutual coupling of capacitive power transfer for wireless power transfer," Electronics Letters, Vol. 51, No. 22, pp. 1806-1807, Oct. 2015.
  7. M. P. Theodoridis, "Effective capacitive power transfer," IEEE Trans. Power Electron., Vol. 27, No. 12, pp. 4906-4913, Dec. 2012.
  8. C. Liu, A. P. Hu, and N. K. C. Nair, "Modelling and analysis of a capacitively coupled contactless power transfer system," IET Power Electronics, Vol. 4, No. 7, pp. 808-815, Aug. 2011.
  9. D. C. Ludois, M. J. Erickson, and J. K. Reed, "Aerodynamic fluid bearings for translational and rotating capacitors in noncontact capacitive power transfer systems," IEEE Trans. Ind. Appl., Vol. 50, No. 2, pp. 1025-1033, Mar./Apr. 2014.
  10. A. P. Hu, C. Liu, and H. L. Li, "A novel contactless battery charging system for soccer playing robot," in International Conference on Mechatronics and Machine Vision in Practice, pp. 623-627, 2008.
  11. A. I. Al-Kalbani, M. R. Yuce, and J. Redoute, "A biosafety comparison between capacitive and inductive coupling in biomedical implants," IEEE Antennas and Wireless Propagation Letters, Vol. 13, No. 1, pp. 1168-1171, Jun. 2014.
  12. B. H. Choi, D. T. Nguyen, S. J. Yoo, J. H. Kim, and C. T. Rim, "A novel source-side monitored capacitive power transfer system for contactless mobile charger using Class-E converter," in Vehicular Technology Conference, pp. 1-5, 2014.
  13. F. Lu, H. Zhang, H. Hofmann, and C. Mi, "A double-sided LCLC-compensated capacitive power transfer system for electric vehicle charging," IEEE Trans. Power Electron., Vol. 30, No. 11, pp. 6011-6014, Nov. 2015.
  14. J. Dai and D. C. Ludois, "Wireless electric vehicle charging via capacitive power transfer through a conformal bumper," in Applied Power Electronics Conference and Exposition, pp. 3307-3313, 2015.
  15. C. Liu, A. P. Hu, B. Wang, and N. C. Nair, "A capacitively coupled contactless matrix charging platform with soft switched transformer control," IEEE Trans. Ind. Electron., Vol. 60, No. 1, pp. 249-260, Jan. 2013.
  16. Y. Su, S. Xie, A. Hu, C. Tang, and W. Zhou, "Transmission property analysis of electric-field coupled wireless power transfer system with LCL resonant network," Transactions of China Electrotechnical Society, Vol. 30, No. 19, pp. 55-60, Oct. 2015.
  17. H. L. Li, A. P. Hu, and G. A. Covic, "Primary current generation for a contact less power transfer system using free oscillation and energy injection control," Journal of Power Electronics, Vol. 11, No. 3, pp. 256-263, May 2011.
  18. G. Wang, P. Wang, Y. Tang, and W. Liu, "Analysis of dual band power and data telemetry for biomedical implants," IEEE Trans. Biomed. Circuits Syst., Vol. 6, No. 3, pp. 208-215, Jun. 2012.
  19. Y. Su, W. Zhou, A. Hu, Y. Sun, and L. Chen, "A power-signal parallel transmission technology for ECPT systems based on duty cycle modulation of square wave carrier," Transactions of China Electrotechnical Society, Vol. 30, No. 21, pp. 51-56, Nov. 2015.
  20. J. Wu, C. Zhao, J. Du, Z. Lin, Y. Hu, and X. He, "Wireless power and data transfer via a common inductive link using frequency division multiplexing," IEEE Trans. Ind. Electron., Vol. 62, No. 12, pp. 7810-7820, Dec. 2015.
  21. J. Hirai, T. Kim, and A. Kawamura, "Integral motor with driver and wireless transmission of power and information for autonomous subspindle drive," IEEE Trans. Power Electron., Vol. 15, No. 1, pp. 13-20, Jan. 2000.
  22. R. L. Steigerwald, "A comparison of half-bridge resonant converter topologies," IEEE Trans. Power Electron., Vol. 3, No. 2, pp. 174-182, Apr. 1988.