# Impact of Coil Misalignment in Data Transmission over the Inductive Link of an EV Wireless Charger

^{1}

^{2}

^{*}

## Abstract

**:**

## 1. Introduction

- (1).
- The coils are realistic for EV applications in terms of their dimensions and size.
- (2).
- Four types of compensation networks are considered, as Series–Series is not the only option considered in EV wireless chargers.
- (3).
- The reflected impedance is not neglected when deriving the electrical magnitudes affecting the computation of the channel capacity.
- (4).
- The vertical, horizontal and joint vertical and horizontal types of misalignments are analysed.

## 2. Overview of a Wireless EV Charger

## 3. Theoretical Analysis of the Coil Misalignment Effects on the Wireless Channel Capacity

## 4. Analysis of the Results

## 5. Conclusions

## Acknowledgments

## Author Contributions

## Conflicts of Interest

## References

- Riehl, P.S.; Satyamoorthy, A.; Akram, H.; Yen, Y.-C.; Yang, J.-C.; Juan, B.; Lee, C.; Lin, F.; Muratov, V.; Plumb, W.; et al. Wireless Power Systems for Mobile Devices Supporting Inductive and Resonant Operating Modes. IEEE Trans. Microw. Theory Tech.
**2015**, 63, 780–790. [Google Scholar] [CrossRef] - Kalwar, K.; Saad, M.; Mekhilef, A. Inductively coupled power transfer (ICPT) for electric vehicle charging—A review. Renew. Sustain. Energy Rev.
**2015**, 47, 462–475. [Google Scholar] [CrossRef] - Wang, Z.; Wei, X. Design Considerations for Wireless Charging Systems with an Analysis of Batteries. Energies
**2015**, 8, 10664–10683. [Google Scholar] [CrossRef] - Triviño-Cabrera, A.; Aguado, J.; González, J.M. Analytical characterisation of magnetic field generated by ICPT wireless charger. Electron. Lett.
**2017**, 53, 871–873. [Google Scholar] [CrossRef] - Niyato, D.; Hoang, D.T.; Wang, P.; Han, Z. Cyber Insurance for Plug-In Electric Vehicle Charging in Vehicle-to-Grid Systems. IEEE Netw.
**2017**, 31, 38–46. [Google Scholar] [CrossRef] - Shaukat, N.; Khan, B.; Ali, S.M.; Mehmood, C.A.; Khan, J.; Farid, U.; Majid, M.; Anwar, S.M.; Jawad, M.; Ullah, Z. A survey on electric vehicle transportation within smart grid system. Renew. Sustain. Energy Rev.
**2018**, 81, 1329–1349. [Google Scholar] [CrossRef] - Zou, Y.; Zhu, J.; Wang, X.; Hanzo, L. A Survey on Wireless Security: Technical Challenges, Recent Advances, and Future Trends. Proc. IEEE
**2016**, 104, 1727–1765. [Google Scholar] [CrossRef] - Wu, J.; Zhao, C.; Lin, Z.; Du, J.; Hu, Y.; He, X. Wireless Power and Data Transfer via a Common Inductive Link Using Frequency Division Multiplexing. IEEE Trans. Ind. Electron.
**2015**, 62, 7810–7820. [Google Scholar] [CrossRef] - Sun, Y.; Yan, P.-X.; Wang, Z.-H.; Luan, Y.-Y. The Parallel Transmission of Power and Data with the Shared Channel for an Inductive Power Transfer System. IEEE Trans. Power Electron.
**2016**, 31, 5495–5502. [Google Scholar] [CrossRef] - Huang, C.-C.; Lin, C.-L.; Wu, Y.-K. Simultaneous Wireless Power/Data Transfer for Electric Vehicle Charging. IEEE Trans. Ind. Electron.
**2017**, 64, 682–690. [Google Scholar] [CrossRef] - De Angelis, A.; Carbone, P.; Sisinni, E.; Flammini, A. Performance Assessment of Chirp-Based Time Dissemination and Data Communications in Inductively Coupled Links. IEEE Trans. Instrum. Meas.
**2017**, 66, 1–9. [Google Scholar] [CrossRef] - Huang, R.; Zhang, B. Frequency, Impedance Characteristics and HF Converters of Two-Coil and Four-Coil Wireless Power Transfer. IEEE J. Emerg. Sel. Top. Power Electron.
**2015**, 3, 177–183. [Google Scholar] [CrossRef] - García-Vázquez, C.; Llorens-Iborra, F.; Fernández-Ramírez, L.; Sánchez-Sain, H.; Jurado, F. Comparative study of dynamic wireless charging of electric vehicles in motorway, highway and urban stretches. Energy
**2017**, 137, 42–57. [Google Scholar] [CrossRef] - Sampath, J.P.K.; Alphones, A.; Vilathgamuwa, D.M. Figure of Merit for the Optimization of Wireless Power Transfer System against Misalignment Tolerance. IEEE Trans. Power Electron.
**2017**, 32, 4359–4369. [Google Scholar] [CrossRef] - Lee, K.; Cho, D.-H. Maximizing the Capacity of Magnetic Induction Communication for Embedded Sensor Networks in Strongly and Loosely Coupled Regions. IEEE Trans. Magn.
**2013**, 49, 5055–5062. [Google Scholar] [CrossRef] - Gulbahar, B. A Communication Theoretical Analysis of Multiple-Access Channel Capacity in Magneto-Inductive Wireless Networks. IEEE Trans. Commun.
**2017**, 65, 2594–2607. [Google Scholar] [CrossRef] - Azad, U.; Jing, H.C.; Wang, Y.E. Link Budget and Capacity Performance of Inductively Coupled Resonant Loops. IEEE Trans. Antennas Propag.
**2012**, 60, 2453–2461. [Google Scholar] [CrossRef] - Ortego-Isasa, I.; Benli, K.P.; Casado, F.; Sancho, J.I.; Valderas, D. Topology Analysis of Wireless Power Transfer Systems Manufactured Via Inkjet Printing Technology. IEEE Trans. Ind. Electron.
**2017**, 64, 7749–7757. [Google Scholar] [CrossRef] - Zhang, W.; Mi, C.C. Compensation Topologies of High-Power Wireless Power Transfer Systems. IEEE Trans. Veh. Technol.
**2016**, 65, 4768–4778. [Google Scholar] [CrossRef] - Jiang, C.; Chau, K.T.; Liu, C.; Lee, C.H.T. An Overview of Resonant Circuits for Wireless Power Transfer. Energies
**2017**, 10, 894. [Google Scholar] [CrossRef] - Lu, X.; Wang, P.; Niyato, D.; Kim, D.I.; Han, Z. Wireless Charging Technologies: Fundamentals, Standards, and Network Applications. IEEE Commun. Surv. Tutor.
**2016**, 18, 1413–1452. [Google Scholar] [CrossRef] - Wang, C.-S.; Covic, G.A.; Stielau, O.H. Power Transfer Capability and Bifurcation Phenomena of Loosely Coupled Inductive Power Transfer Systems. IEEE Trans. Ind. Electron.
**2004**, 51, 148–157. [Google Scholar] [CrossRef] - Villa, J.L.; Sallan, J.; Osorio, J.F.S.; Llombart, A. High-Misalignment Tolerant Compensation Topology for ICPT Systems. IEEE Trans. Ind. Electron.
**2012**, 59, 945–951. [Google Scholar] [CrossRef] - Xiao, C.; Liu, Y.; Cheng, D.; Wei, K. New Insight of Maximum Transferred Power by Matching Capacitance of a Wireless Power Transfer System. Energies
**2017**, 10, 688. [Google Scholar] - Dehui, W.; Qisheng, S.; Xiaohong, W.; Fan, Y. Analytical Model of Mutual Coupling between Rectangular Spiral Coils with Lateral Misalignment for Wireless Power Applications. Available online: http://digital-library.theiet.org/content/journals/10.1049/iet-pel.2017.0470 (accessed on 28 February 2018).
- Joy, E.R.; Dalal, A.; Kumar, P. Accurate Computation of Mutual Inductance of Two Air Core Square Coils with Lateral and Angular Misalignments in a Flat Planar Surface. IEEE Trans. Magn.
**2014**, 50, 1–9. [Google Scholar] [CrossRef]

**Figure 1.**Structure of an Inductively Coupled Power Transfer (ICPT) wireless charger for electric vehicles (EV).

**Figure 3.**Illustration of the types of coil misalignments that may occur in an EV wireless charger: (

**a**) vertical misalignment; (

**b**) horizontal misalignment; (

**c**) vertical and horizontal misalignment.

**Figure 4.**Variations in the wireless channel capacity due to vertical misalignments. SS, Series–Series; SP, Series–Parallel; PP, Parallel–Parallel; PS, Parallel–Series; PSIM (Power Simulation Technology).

Topology | ${\mathit{C}}_{1}$ | ${\mathit{C}}_{2}$ |
---|---|---|

Series–Series | $\frac{1}{{\omega}^{2}{L}_{1}}$ | $\frac{1}{{\omega}^{2}{L}_{2}}$ |

Series–Parallel | $\frac{{L}_{2}^{2}{C}_{2}}{{L}_{1}{L}_{2}-{M}^{2}}$ | $\frac{1}{{\omega}^{2}{L}_{2}}$ |

Parallel–Series | $\frac{{L}_{2}{C}_{2}}{{L}_{1}+\frac{{M}^{4}}{{L}_{1}{L}_{2}{C}_{2}{R}_{b}^{2}}}$ | $\frac{1}{{\omega}^{2}{L}_{2}}$ |

Parallel–Parallel | $\frac{\left({L}_{1}{L}_{2}-{M}^{2}\right){L}_{2}^{2}{C}_{2}}{\frac{{M}^{4}{R}_{L}^{2}{C}_{2}}{{L}_{2}}+{\left({L}_{1}{L}_{2}-{M}^{2}\right)}^{2}}$ | $\frac{1}{{\omega}^{2}{L}_{2}}$ |

Parameter | Value |
---|---|

Output | 3.7 kW @ 300 V |

f [kHz] | 85 |

N_{1} [number of turns in the primary coil] | 11 |

N_{2} [number of turns in the secondary coil] | 14 |

a1 × b1 [m^{2}] | 0.75 × 0.75 |

a2 × b2 [m^{2}] | 0.5 × 0.5 |

gd [m] | 0.2 |

L_{1} [µH] | 240.5 |

L_{2} [µH] | 230.6 |

R_{1} [mΩ] | 196 |

R_{2} [mΩ] | 143 |

R_{b} [Ω] | 30 |

C_{2} [nF] | 15.20 |

C_{1} [nF] @ SS | 14.57 |

C_{1} [nF] @ SP | 15.02 |

C_{1} [nF] @ PS | 15.02 |

C_{1} [nF] @ PP | 14.36 |

M [µH] @ gap = 15 cm, xm = 0 cm | 49.78 |

M [µH] @ gap = 20 cm, xm = 0 cm | 40.8 |

M [µH] @ gap = 25 cm, xm = 0 cm | 33.38 |

M [µH] @ xm = 5 cm, gap = gd | 40.39 |

M [µH] @ xm = 10 cm, gap = gd | 39.07 |

M [µH] @ xm = 15 cm, gap = gd | 36.72 |

M [µH] @ xm = 5 cm, gap = 10 cm | 59.9 |

M [µH] @ xm = 10 cm, gap = 20 cm | 39.07 |

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

## Share and Cite

**MDPI and ACS Style**

Triviño-Cabrera, A.; Lin, Z.; Aguado, J.A. Impact of Coil Misalignment in Data Transmission over the Inductive Link of an EV Wireless Charger. *Energies* **2018**, *11*, 538.
https://doi.org/10.3390/en11030538

**AMA Style**

Triviño-Cabrera A, Lin Z, Aguado JA. Impact of Coil Misalignment in Data Transmission over the Inductive Link of an EV Wireless Charger. *Energies*. 2018; 11(3):538.
https://doi.org/10.3390/en11030538

**Chicago/Turabian Style**

Triviño-Cabrera, Alicia, Zhengyu Lin, and José A. Aguado. 2018. "Impact of Coil Misalignment in Data Transmission over the Inductive Link of an EV Wireless Charger" *Energies* 11, no. 3: 538.
https://doi.org/10.3390/en11030538