Wireless power transmission device and system using impedance matching

• US 10,700,544 B2
• Filed: 02/02/2018
• Issued: 06/30/2020
• Est. Priority Date: 08/05/2014
• Status: Active Grant

• Current Assignee: Korea Electrotechnology Research Institute
• Original Assignee: Korea Electrotechnology Research Institute
• Inventors: Park, Young Jin, Kim, Jin Wook
• Primary Examiner(s): Zhou, Zixuan
• Application Number:
  US15/887,847
• Publication Number:
  US 20180159359A1
• Time in Patent Office: 879 Days
• Field of Search: 320108, 307104
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0024 Parallel/serial switching of connection of batteries to charge or load circuit
• CPC Class Codes: H03H 7/38 Impedance-matching networks

Abstract

The present invention relates to a battery charging system using wireless power transmission, including a charging power supply device that comprises: a power supply unit that supplies power for wireless power transmission; a power transmission unit that comprises at least one power transmission coil and wirelessly transmits power for charging a battery; and a transmission impedance matching unit that matches the impedance between the power supply unit and the power transmission unit; and a battery charging device that receives power wirelessly transmitted from the charging power supply device through power reception coils individually corresponding to one or more batteries and charges the batteries. According to the present invention, a plurality of unit batteries can be simultaneously charged by one charging power supply device, that is, one transmission module. With this advantage, a plurality of battery cells can be simultaneously charged wirelessly without wires, and quick charging is also possible.

Claims

1. A battery charging system using wireless power transmission, comprising:

a charging power supply device that comprises at least one power transmission coil and wirelessly transmits power for simultaneously charging a plurality of batteries; and

a battery charging device that receives power wirelessly transmitted from the charging power supply device through a plurality of power reception coils respectively corresponding to the plurality of batteries and that simultaneously charges the plurality of batteries, the battery charging device comprising;

a reception control unit that controls power charged to each battery by taking into account a charging state of each of the plurality of batteries, and

a plurality of reception impedance matching units respectively corresponding to the plurality of batteries,

wherein the battery charging device controls the plurality of reception impedance matching units according to the respective charging states of the plurality of batteries to simultaneously supply power to each battery, and

wherein the reception control unit selects a battery of the plurality to concentrate charging power to and adjusts an impedance of a reception impedance matching unit corresponding to the selected battery to increase a ratio of power supplied to the battery to power simultaneously supplied through the plurality of power reception coils by the charging power supply device.

2. The battery charging system of claim 1, wherein the reception control unit is provided in plurality to individually correspond to the plurality of batteries.

3. The battery charging system of claim 1, wherein the reception control unit is implemented with one module that controls charging of the plurality of batteries.

4. The battery charging system of claim 1, wherein the reception impedance matching units each comprise a first reception capacitor connected in parallel to an input terminal and a second reception capacitor connected in series to the first reception capacitor.

5. The battery charging system of claim 1, wherein the reception impedance matching units each comprise a first reception capacitor connected in series to an input terminal and a second reception capacitor connected in parallel to the first reception capacitor.

6. The battery charging system of claim 1, wherein the charging power supply device comprises a transmission control unit that controls the wirelessly transmitted power, and

the transmission control unit and the reception control unit interwork with each other to adjust the wirelessly transmitted power and the charged power.

7. The battery charging system of claim 6, wherein the transmission control unit comprises a transmission communication unit for wired or wireless communication with the reception control unit,

the reception control unit comprises a reception communication unit for wired or wireless communication with the transmission control unit, and

the transmission control unit controls a transmission power amount based on charging state information of the plurality of batteries that is transmitted from the reception control unit.

8. The battery charging system of claim 6, wherein the reception impedance matching units each comprise a first reception capacitor connected in parallel to an input terminal and a second reception capacitor connected in series to the first reception capacitor.

9. The battery charging system of claim 6, wherein the reception impedance matching units each comprise a first reception capacitor connected in series to an input terminal and a second reception capacitor connected in parallel to the first reception capacitor.

10. The battery charging system of claim 6, wherein the transmission control unit of the charging power supply device adjusts impedance of an impedance matching unit to control power supplied to the power transmission coil.

11. The battery charging system of claim 1, wherein the reception control unit of the battery charging device adjusts impedance of an impedance matching unit of each battery to control power charged to each battery.

12. The battery charging system of claim 1, wherein the control unit collects state information on the plurality of batteries from a plurality of battery charging units respectively, and adjusts impedance matching of the plurality of reception impedance matching units based on the state information, so as to adjust the ratio of power supplied to the battery to the power simultaneously supplied through the plurality of power reception coils by the charging power supply device.

13. The battery charging system of claim 1, wherein when the impedances of the reception impedance matching units are changed, each of the batteries is charged within a predetermined power transfer efficiency range.

14. The battery charging system of claim 1, wherein the charging power supply device comprises a wireless power transmission device capable of wirelessly transmitting power to a plurality of wireless power reception devices in a wireless power transmission system, the wireless power transmission device comprising:

a power transmission unit that comprises the at least one power transmission coil and transmits power to the wireless power reception devices;

a power supply unit that supplies power to the power transmission unit;

a transmission impedance matching unit that adjusts impedance between the power supply unit and the power transmission unit; and

a transmission control unit that controls the power wirelessly transmitted simultaneously to the plurality of wireless power reception devices and that communicates with a plurality of reception control units, the plurality of reception control units being respectively included in the plurality of wireless power reception devices,

wherein the transmission control unit receives from the plurality of reception control units the charging state information of respective batteries of the plurality of wireless power reception devices and controls the wirelessly transmitted power based on the charging state information to simultaneously charge the respective batteries of the plurality of wireless power reception devices, and

wherein the plurality of wireless power reception devices includes the battery charging device,

wherein the plurality of reception control units includes the reception control unit of the battery charging device, and

wherein the plurality of batteries includes the respective batteries of the plurality of wireless power reception devices.

15. The battery charging system of claim 1, wherein the battery charging device includes a wireless power reception device that receives power from a wireless power transmission device capable of wirelessly transmitting power simultaneously to a plurality of wireless power reception devices in a wireless power transmission system, the wireless power transmission device including the charging power supply device, and the wireless power reception device comprising:

a power reception unit comprising a power reception coil of the plurality of power reception coils, the power reception unit configured to receive power wirelessly transmitted from the wireless power transmission device;

a module power supply unit that supplies the power received from the power reception unit to a module, the module including at least one battery of the plurality of batteries;

a reception impedance matching unit corresponding to the module that performs impedance matching between the power reception unit and the module power supply unit,

wherein the reception control unit [[that]] controls power supplied to the module by taking into account a charging state of the module and communicates with the wireless power transmission device, and

wherein the reception control unit transmits information regarding the charging state of the module to the wireless power transmission device.

16. The wireless power reception device of claim 15, wherein the reception control unit controls power supplied to the module by controlling an impedance of the reception impedance matching unit corresponding to the module.

17. The wireless power reception device of claim 16,

wherein the module power supply unit measures the state of the module, and

wherein the reception control unit controls the impedance of the reception impedance matching unit corresponding to the module according to the state of the module measured by the module power supply unit.

18. The wireless power reception device of claim 15, wherein the reception impedance matching unit corresponding to the module comprises a first reception capacitor connected in parallel to the power supply unit and a second reception capacitor connected in series to the first reception capacitor.

19. The wireless power reception device of claim 15, wherein the reception impedance matching unit corresponding to the module comprises a first reception capacitor connected in series to the power supply unit and a second reception capacitor connected in parallel to the first reception capacitor.

20. The wireless power reception device of claim 15, wherein the information regarding the charging state of the module includes information regarding an amount of charging of the module.