**Author details**

**Figure 21.** Magnetic field cancellation using a resonant coil.

124 Wireless Power Transfer - Fundamentals and Technologies

KAIST published a paper in 2013, proposing an active shielding method using a resonant coil. A switching array is used to change the values of compensated capacitors, thereby controlling the amplitude and phase of the cancelling field. An experiment was performed using green public transportation [25]. In 2015, an improved version using double loop and phase adjust‐ ment to achieve resonance was proposed to achieve an active shielding without power supply. The shielding coils are placed at the side of the coupling mechanism as shown in **Figure 22**. The current induced by leakage field is then sensed. Magnetic field with the same amplitude

In 2013, ORNL proposed using an aluminum board to reduce electromagnetic interference [27]. As shown in **Figure 23**, a 1‐mm‐thick aluminum shield is placed above the cables. The magnetic field measured at the passenger‐side front tire is reduced from 18.72 μT to 3.22 μT.

but opposite polarity with the leakage is then created for field cancellation [26].

**Figure 22.** Resonant reactive power shielding with double coils and four capacitors.

**Figure 23.** Suppression of magnetic field after adding aluminum plate and its effect.

Kai Song1\*, Kim Ean Koh2 , Chunbo Zhu1 , Jinhai Jiang1 , Chao Wang1 and Xiaoliang Huang2

\*Address all correspondence to: kaisong@hit.edu.cn

1 School of Electrical Engineering, Harbin Institute of Technology, Harbin, China

2 Department of Electrical Engineering, The University of Tokyo, Tokyo, Japan

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