Figure 1.
Passive shielding using ferrite [
14].
Figure 1.
Passive shielding using ferrite [
14].
Figure 2.
Passive shielding using conductive materials [
14].
Figure 2.
Passive shielding using conductive materials [
14].
Figure 3.
Active shielding using additional power sources.
Figure 3.
Active shielding using additional power sources.
Figure 4.
Resonant reactive current shielding.
Figure 4.
Resonant reactive current shielding.
Figure 5.
Electromagnetic wave behavior inside and outside of the shielding materials.
Figure 5.
Electromagnetic wave behavior inside and outside of the shielding materials.
Figure 6.
Wireless power transfer (WPT) system pad structure in the presence of ferrite cores.
Figure 6.
Wireless power transfer (WPT) system pad structure in the presence of ferrite cores.
Figure 7.
Power transfer efficiency in the absence and the presence of ferrite cores after readjusting the capacitors.
Figure 7.
Power transfer efficiency in the absence and the presence of ferrite cores after readjusting the capacitors.
Figure 8.
Power transfer efficiency in the absence and the presence of ferrite cores after readjusting the capacitors.
Figure 8.
Power transfer efficiency in the absence and the presence of ferrite cores after readjusting the capacitors.
Figure 9.
Magnetic field intensity (A/m), (a) two coils w/o ferrite core; (b) two coils with ferrite cores.
Figure 9.
Magnetic field intensity (A/m), (a) two coils w/o ferrite core; (b) two coils with ferrite cores.
Figure 10.
WPT approximation model in the presence of metallic materials.
Figure 10.
WPT approximation model in the presence of metallic materials.
Figure 11.
WPT system pad structure in the presence of ferrite cores and Al plates.
Figure 11.
WPT system pad structure in the presence of ferrite cores and Al plates.
Figure 12.
System performances for coils with ferrite cores and with ferrite and Al plates.
Figure 12.
System performances for coils with ferrite cores and with ferrite and Al plates.
Figure 13.
Magnetic field intensity (A/m), (a) two coils with ferrite core; (b) two coils with ferrite cores and Al plates.
Figure 13.
Magnetic field intensity (A/m), (a) two coils with ferrite core; (b) two coils with ferrite cores and Al plates.
Figure 14.
WPT system with the resonant reactive current shielding equivalent circuit model.
Figure 14.
WPT system with the resonant reactive current shielding equivalent circuit model.
Figure 15.
Resonant reactive shield impedance; (a) impedance magnitude; and (b) impedance phase.
Figure 15.
Resonant reactive shield impedance; (a) impedance magnitude; and (b) impedance phase.
Figure 16.
The proposed shielding loop positions; (a) the two loops on the same levels with the WPT coils, and (b) the two loops located above and under the ferrite cores.
Figure 16.
The proposed shielding loop positions; (a) the two loops on the same levels with the WPT coils, and (b) the two loops located above and under the ferrite cores.
Figure 17.
Observation points configurations for testing the Electromagnetic Field (EMF) level on the x and z-axes.
Figure 17.
Observation points configurations for testing the Electromagnetic Field (EMF) level on the x and z-axes.
Figure 18.
The EMF level for the two proposed designs observed on (a) z-axis points and (b) x-axis points.
Figure 18.
The EMF level for the two proposed designs observed on (a) z-axis points and (b) x-axis points.
Figure 19.
Magnetic flux distributions for side plane (T); (a) case 1 and (b) case 2.
Figure 19.
Magnetic flux distributions for side plane (T); (a) case 1 and (b) case 2.
Figure 20.
The total pad weight for the three proposed shielding techniques.
Figure 20.
The total pad weight for the three proposed shielding techniques.
Figure 21.
The magnetic flux density distribution (T), (a) is the ferrite shield; (b) is the aluminum shield; and (c) is the resonant reactive current shield.
Figure 21.
The magnetic flux density distribution (T), (a) is the ferrite shield; (b) is the aluminum shield; and (c) is the resonant reactive current shield.
Figure 22.
The experimental set-up.
Figure 22.
The experimental set-up.
Figure 23.
Measurement and simulation B-Mag (T) on the z-axis for the three shielding types.
Figure 23.
Measurement and simulation B-Mag (T) on the z-axis for the three shielding types.
Figure 24.
Measurement and simulation B-Mag (T) on the x-axis for the three shielding types.
Figure 24.
Measurement and simulation B-Mag (T) on the x-axis for the three shielding types.
Table 1.
The simulation design parameters.
Table 1.
The simulation design parameters.
Parameters | Value | Description |
---|
The WPT coil radius | 20 cm | Litz wire = 3.5 mm |
The ferrite core radius | 22.5 cm | S/m |
Ferrite core thickness (F-th) | 3 mm | - |
WPT coils Number of turns | 20 turns | - |
Air gap (d) | 15 cm | - |
Operating frequency | 85 kHz | - |
Power transfer | 500 W | - |
Table 2.
The simulation design results for coils and coils with cores.
Table 2.
The simulation design results for coils and coils with cores.
Parameters | Coils Only | Coils with Ferrite Cores |
---|
Tx Self-inductance (H) | | |
Rx Self-inductance (H) | | |
Mutual inductance (H) | | |
The coupling coefficient | | |
Primary current (A) | | |
Secondary current (A) | | |
Table 3.
The simulation design parameters.
Table 3.
The simulation design parameters.
Parameters | Value | Description |
---|
The WPT coil radius | 20 cm | Litz wire = 3.5 mm |
The ferrite core radius | 22.5 cm | = 4000; S/m |
The ferrite core thickness (F-th) | 3 mm | - |
Al plates radius | 30 cm | = 1; S/m |
Al plate thickness (Al-th) | 3 mm | - |
The WPT coil Number of turns | 20 turns | - |
Air gap (d) | 15 cm | - |
Operating frequency | 85 kHz | - |
Power transfer | 500 W | - |
Table 4.
The simulation design results for coils with ferrite and coils with core and shields.
Table 4.
The simulation design results for coils with ferrite and coils with core and shields.
Parameters | Coils with Ferrite | Coils with Ferrite and Al |
---|
Tx Self-inductance (H) | | |
Rx Self-inductance (H) | | |
Mutual inductance (H) | | |
The coupling coefficient | | |
Primary current (A) | | |
Secondary current (A) | | |
Table 5.
The design parameters of the Resonant Reactive Current (RRC) shielding loop position.
Table 5.
The design parameters of the Resonant Reactive Current (RRC) shielding loop position.
Parameters | Value | Description |
---|
The ferrite core radius | 22.5 cm | = 4000; S/m |
The shielding loop radius | 22.5 cm | Litz wire = 3.5 mm |
The WPT coil radius | 20 cm | Litz wire = 3.5 mm |
The ferrite core thickness | 5 mm | - |
RRC loop Number of turns | 3 turns | - |
WPT coil Number of turns | 20 turns | - |
Air gap | 15 cm | - |
Table 6.
The proposed shielding techniques’ design parameters.
Table 6.
The proposed shielding techniques’ design parameters.
Parameters | Value | Specifications |
---|
WPT coil loop radius | 20 cm | Litz wire = 3.5 mm; S/m; 8933 kg/m |
WPT coil number of turns | 20 turns | - |
Ferrite core radius | 22.5 cm | = 4000; S/m; 7870 kg/m |
Ferrite core thickness | 0.5 cm | - |
Al shield thickness | 0.5 cm | - |
Al shield radius | 25 cm | S/m; 2689 kg/m |
The reonant loop radius | 22.5 cm | - |
The resonant shield number of turns | 3 turns | - |
Air-gap | 15 cm | - |
Operating frequency | 85 kHz | - |
Power transfer | 5 kW | - |
Table 7.
Electromagnetic Field (EMF) averages for z-axis and x-axis observation points.
Table 7.
Electromagnetic Field (EMF) averages for z-axis and x-axis observation points.
The Shielding Type | z-Axis EMF | % | x-Axis EMF | % |
---|
Ferrite shield | | | | |
Al shield | | | | |
Resonant shield | | | | |
Table 8.
The inductances comparison for the proposed causes.
Table 8.
The inductances comparison for the proposed causes.
The Shielding Type | (T) | % | (T) | % | M (T) | % |
---|
Ferrite shield | | | | | | |
Al shield | | | | | | |
RRC shield | | | | | | |