Power transmission system
A power transmission system that can prevent a plunge in power transmission efficiency even when there is a positional shift of a power reception antenna with respect to a power transmission antenna. A power transmission system includes: a power transmission antenna that includes a wound power transmission coil that is placed on the ground; a power reception antenna that is disposed in such a way as to face the power transmission antenna, includes a wound power reception coil, and receives electric energy from the power transmission antenna via an electromagnetic field, wherein an area of a first projection plane that is formed by the power transmission coil in a vertical direction with respect to a horizontal plane is larger than an area of a second projection plane that is formed by the power reception coil in the vertical direction with respect to the horizontal plane.
1. A power transmission system comprising:
a power transmission antenna that includes a racetrack-shaped wound power transmission coil, having a long side, that is placed on the ground; and
a power reception antenna that is disposed in such a way as to face the power transmission antenna, includes a wound power reception coil, and receives electric energy from the power transmission antenna via an electromagnetic field, wherein
an area of a first projection plane that is formed by the power transmission coil in a vertical direction with respect to a horizontal plane is larger than an area of a second projection plane that is formed by the power reception coil in the vertical direction with respect to the horizontal plane,
when a distance between inner edges of the power transmission coil in a predetermined direction is represented by T i , a distance between outer edges of the power transmission coil in the predetermined direction is represented by T o , a distance between inner edges of the power reception coil in the predetermined direction is represented by R i , and a distance between outer edges of the power reception coil in the predetermined direction is represented by R o , the following relation is satisfied: T i <R i <R o <T o ,
the predetermined direction is a direction perpendicular to a direction in which a positional shift occurs between the power reception antenna and the power transmission antenna, and
in the direction in which the positional shift occurs, an internal diameter of the power transmission coil is larger than an internal diameter of the wound power reception coil, such that:
L
1
C
1
>
L
2
C
2
wherein the inductance component of the power transmission antenna is represented by L 1 , the capacitance component of the power transmission antenna is represented by C 1 , the inductance component of the power reception antenna is represented by L 2 , and the capacitance component of the power reception antenna is represented by C 2 .
2. The power transmission system according to claim 1 , wherein the long side of the race track-shaped wound power transmission coil is parallel to a width of a vehicle in which the power reception antenna is installed, when the vehicle is parked.