Wireless power transmission system and method for designing the same
A wireless power transmission system includes a transmitting antenna, a power supply for supplying power of a resonance frequency f 0 to the transmitting antenna, a first capacitor connected in series to the transmitting antenna, a receiving antenna magnetically coupled to the transmitting antenna, a load connected to the receiving antenna, and a second capacitor connected in series to the receiving antenna. Supposing that the coupling factor between the transmitting antenna and the receiving antenna is represented by k, the internal resistance of the power supply by Rs and the resistance of the load by R L , then the self-inductance L S of the transmitting antenna and the self-inductance L L of the receiving antenna are determined to satisfy an equation: L S ×L L =R S ×R 1 /(2πf 0 k) 2 . Further, the capacitance C S of the first capacitor and the capacitance C L of the second capacitor are determined to satisfy equations: C S =1/(2πf 0 ) 2 L S and C L =1/(2πf 0 ) 2 L L .
1. A wireless power transmission system comprising:
a transmitting antenna;
a power supply for supplying electric power of a resonance frequency f 0 to the transmitting antenna;
a first capacitor connected in series to the transmitting antenna;
a receiving antenna magnetically coupled to the transmitting antenna;
a load connected to the receiving antenna; and
a second capacitor connected in series to the receiving antenna;
wherein when a coupling factor between the transmitting antenna and the receiving antenna is represented by k, an internal resistance of the power supply is represented by Rs and a resistance of the load is represented by R L ,
a self-inductance L S of the transmitting antenna and a self-inductance L L of the receiving antenna satisfy equation (1) below:
L
S
×
L
L
=
R
S
×
R
L
(
2
π
f
0
k
)
2
(
1
)
and a capacitance C S of the first capacitor and a capacitance C L of the second capacitor satisfy equations (2), (3) below:
C
S
=
1
(
2
π
f
0
)
2
L
S
(
2
)
C
L
=
1
(
2
π
f
0
)
2
L
L
.
(
3
)
2. The wireless power transmission system according to claim 1 , wherein the self-inductance L S of the transmitting antenna and the self-inductance L L of the receiving antenna are equal to each other.
3. The wireless power transmission system according to claim 1 , wherein the transmitting antenna comprises two electroconductive line elements parallel to each other.
4. The wireless power transmission system according to claim 2 , wherein the transmitting antenna comprises two electroconductive line elements parallel to each other.
5. A method for designing a wireless power transmission system that includes a transmitting antenna, a power supply for supplying electric power of a resonance frequency f 0 to the transmitting antenna, a first capacitor connected in series to the transmitting antenna, a receiving antenna magnetically coupled to the transmitting antenna, a load connected to the receiving antenna, and a second capacitor connected in series to the receiving antenna, where a coupling factor between the transmitting antenna and the receiving antenna is represented by k, an internal resistance of the power supply is represented by R S and a resistance of the load is represented by R L ,
the method comprising:
a first step of setting a self-inductance L S of the transmitting antenna and a self-inductance L L of the receiving antenna so as to satisfy equation (4) below:
L
S
×
L
L
=
R
S
×
R
L
(
2
π
f
0
k
)
2
,
(
4
)
and
a second step of setting a capacitance C S of the first capacitor and a capacitance C L of the second capacitor so as to satisfy equations (5) and (6) below:
C
S
=
1
(
2
π
f
0
)
2
L
S
(
5
)
C
L
=
1
(
2
π
f
0
)
2
L
L
.
(
6
)