Wireless power transfer system for selectively driving at least one transmitting coil among transmitting coils and operation method thereof
Disclosed a wireless power transfer system configured to selectively drive at least one transmitting coil among transmitting coils that are included in a transmitter; and an operation method of the wireless power transfer system, and more particularly, to a technology of verifying a coupling coefficient between each of transmitting coils and a receiving coil when the receiving coil is located on the transmitting coils and selectively driving at least one transmitting coil among the transmitting coils based on the verified coupling coefficient. According to an embodiment of the present disclosure, the wireless power transfer system includes a transmitter including the transmitting coils; a receiver including a receiving coil configured to receive wireless power from at least one transmitting coil among the transmitting coils; and a controller configured to verify a coupling coefficient between each of the transmitting coil and the receiving coil and selectively drive the at least one transmitting coil based on the verified coupling coefficient.
1. A wireless power transfer system for selectively driving at least one transmitting coil among transmitting coils, comprising:
a transmitter comprising the transmitting coils;
a receiver comprising a receiving coil configured to receive wireless power from at least one transmitting coil among the transmitting coils; and
a controller configured to verify a coupling coefficient between each of the transmitting coil and the receiving coil and selectively drive the at least one transmitting coil based on the verified coupling coefficient,
wherein the controller arranges the verified coupling coefficients in descending order and determines a driving order of the transmitting coils based on the coupling coefficients arranged in the descending order,
wherein the controller selectively drives the at least one transmitting coil based on the verified coupling coefficients and an equation 1 below:
k
m
>
m
(
m
-
1
)
-
(
m
-
1
)
m
-
1
(
∑
i
=
1
m
-
1
k
i
)
wherein the equation 1 comprises k m representing a coupling coefficient of an m-th transmitting coil, i representing “1”, k i representing a coupling coefficient of an i-th transmitting coil and m representing the driving order determined for a plurality of transmitting orders and to be any number from 2 to n, and
wherein the controller determines a coupling coefficient of k i while determining a coupling coefficient of k m by substituting the order of the transmitting coil according to the determined driving order into m.
2. The wireless power transfer system according to claim 1 , wherein the controller selectively drives a transmitting coil corresponding to m of k m when a coupling coefficient ratio between the coupling coefficient of k m and the coupling coefficient of k i is greater than a value calculated by an equation 2 below:
m
(
m
-
1
)
-
(
m
-
1
)
m
-
1
wherein the equation 2 comprises m representing an operating order determined for a plurality of transmitting orders and to be any number from 2 to n.
3. The wireless power transfer system according to claim 1 , wherein the controller verifies a coupling coefficient according to a position of a center of the receiving coil on the transmitting coils, determines a driving order of the transmitting coils using the verified coupling coefficient, and selectively drives at least one transmitting coil satisfying an equation 1 below by substituting the order of the transmitting coils based on the determined driving order into the equation 1 below:
k
m
>
m
(
m
-
1
)
-
(
m
-
1
)
m
-
1
(
∑
i
=
1
m
-
1
k
i
)
4. A method of operating a wireless power transfer system comprising a transmitter comprising transmitting coils; a receiver comprising a receiving coil configured to receive wireless power from at least one transmitting coil among the transmitting coils; and a controller configured to control operation of the transmitter and the receiver,
the method comprising:
verifying, by the controller, a coupling coefficient between each of the transmitting coils and the receiving coil;
arranging, by the controller, the verified coupling coefficients in descending order and determining a driving order of the transmitting coils based on the coupling coefficients arranged in the descending order; and
selectively driving, by the controller, the at least one transmitting coil based on the verified coupling coefficient and an equation 1 below:
k
m
>
m
(
m
-
1
)
-
(
m
-
1
)
m
-
1
(
∑
i
=
1
m
-
1
k
i
)
wherein the equation 1 comprises k m representing a coupling coefficient of an m-th transmitting coil, i representing “1”, k i representing a coupling coefficient of an i-th transmitting coil and m representing the driving order determined for a plurality of transmitting orders and to be any number from 2 to n, and
wherein the selectively driving comprises:
determining a coupling coefficient of k i while determining a coupling coefficient of k m by substituting the order of the transmitting coil according to the determined driving order into m.
5. The method according to claim 4 , wherein the selectively driving comprises:
selectively driving a transmitting coil corresponding to m when a coupling coefficient ratio between the coupling coefficient of k m and the coupling coefficient of k i is greater than a value calculated by an equation 2 below:
m
(
m
-
1
)
-
(
m
-
1
)
m
-
1
wherein the equation 2 comprises m representing an operating order determined for a plurality of transmitting orders and to be any number from 2 to n.