Wireless power transmitting apparatus and method thereof

• US 10,148,127 B2
• Filed: 01/23/2014
• Issued: 12/04/2018
• Est. Priority Date: 01/29/2013
• Status: Active Grant

• Current Assignee: LG Innotek Company Limited (LG Corporation)
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Bae, Su Ho
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Evans, James
• Application Number:
  US14/763,934
• Publication Number:
  US 20150372497A1
• Time in Patent Office: 1,776 Days
• Field of Search: None
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields

Abstract

Disclosed is a wireless power transmitting apparatus to wirelessly transmit power to a wireless power receiving apparatus through a transmission resonance coil by using resonance. An AC power generating unit generates quasi square-wave AC power having quasi square-wave voltage. A transmission induction coil transmits the quasi square-wave AC power to the transmission resonance coil through electromagnetic induction.

Claims

1. A wireless power transmitting apparatus to wirelessly transmit power to a wireless power receiving apparatus through a transmission resonance coil using resonance, the wireless power transmitting apparatus comprising:

an AC power generating unit to generate quasi square-wave AC power having quasi square-wave voltage; and

a transmission induction coil to transmit the quasi square-wave AC power to the transmission resonance coil through electromagnetic induction,

wherein an input impedance of the wireless power transmitting apparatus has a maximum value at a fundamental frequency component, and

wherein the input impedance of the wireless power transmitting apparatus has a minimum value at a second harmonic frequency component, and is increased as an order of a harmonic frequency component is increased from the second harmonic frequency component.

2. The wireless power transmitting apparatus of claim 1, wherein a duty ratio of the quasi square-wave AC power has a value allowing a power ratio of the quasi square-wave AC power at the fundamental frequency component to be greater than a power ratio of square-wave AC power at a fundamental frequency component when a duty ratio of the square-wave AC power is 50%.

3. The wireless power transmitting apparatus of claim 2, wherein the duty ratio of the quasi square-wave AC power is in a range of 23% to 48%.

4. The wireless power transmitting apparatus of claim 3, wherein the duty ratio of the quasi square-wave AC power is in a range of 28% to 34%.

5. The wireless power transmitting apparatus of claim 4, wherein the duty ratio of the quasi square-wave AC power is in a range of 29% to 31%.

6. The wireless power transmitting apparatus of claim 1, wherein a duty ratio of the quasi square-wave AC power has a value allowing a power ratio of the quasi square-wave AC power at the fundamental frequency component to be greater than a power ratio of square-wave AC power at a fundamental frequency component when a duty ratio of the square-wave AC power is 50%.

7. The wireless power transmitting apparatus of claim 1, wherein a duty ratio of the quasi square-wave AC power has a value allowing a power ratio of the quasi square-wave AC power at the fundamental frequency component to be greater than a power ratio of square-wave AC power at a fundamental frequency component when a duty ratio of the square-wave AC power is 50%.

8. A method of wirelessly transmitting power to a wireless power receiving apparatus through a transmission resonance coil using resonance by a wireless power transmitting apparatus, the method comprising:

generating quasi square-wave AC power having quasi square-wave voltage; and

transmitting the quasi square-wave AC power to the transmission resonance coil through electromagnetic induction,

wherein an input impedance of the wireless power transmitting apparatus has a maximum value at a fundamental frequency component, and

wherein the input impedance of the wireless power transmitting apparatus has a minimum value at a second harmonic frequency component, and is increased as an order of a harmonic frequency component is increased from the second harmonic frequency component.

9. The method of claim 8, further comprising:

generating DC power;

generating a sine wave; and

generating an AC power control signal based on the sine wave,

wherein the generating of the quasi square-wave AC power having the quasi square-wave voltage comprises generating the quasi square-wave AC power based on the AC power control signal.

10. The method of claim 9, wherein a duty ratio of the quasi square-wave AC power has a value allowing a power ratio of the quasi square-wave AC power at the fundamental frequency component to be greater than a power ratio of square-wave AC power at the fundamental frequency component when a duty ratio of the square-wave AC power is 50%.

11. The method of claim 8, wherein a duty ratio of the quasi square-wave AC power has a value allowing a power ratio of the quasi square-wave AC power at the fundamental frequency component to be greater than a power ratio of square-wave AC power at the fundamental frequency component when a duty ratio of the square-wave AC power is 50%.

12. A wireless power transmitting apparatus to wirelessly transmit power to a wireless power receiving apparatus through a transmission resonance coil using resonance, the wireless power transmitting apparatus comprising:

an AC power control unit to generate an AC power control signal;

a full-bridge structure transistor circuit part to output quasi square-wave AC power having quasi square-wave voltage based on the AC power control signal; and

a transmission induction coil to transmit the quasi square-wave AC power to the transmission resonance coil through electromagnetic induction,

wherein an input impedance of the wireless power transmitting apparatus has a maximum value at a fundamental frequency component, and

wherein the input impedance of the wireless power transmitting apparatus has a minimum value at a second harmonic frequency component, and is increased at a second harmonic frequency component or more as an order of a harmonic frequency component is increased.

13. The wireless power transmitting apparatus of claim 12, wherein the full-bridge structure transistor circuit part comprises:

a first transistor comprising a drain electrode, to which DC power is applied, and a source electrode connected to one terminal of the transmission induction coil;

a second transistor comprising a drain electrode connected to the source electrode of the first transistor and a source electrode connected to a ground;

a third transistor comprising a drain electrode, to which the DC power is applied, and a source electrode connected to an opposite terminal of the transmission induction coil; and

a fourth transistor comprising a drain electrode connected to the source electrode of the third transistor and a source electrode connected to the ground,

wherein the source electrode of the first transistor and the source electrode of the third transistor output the quasi square-wave AC power.

14. The wireless power transmitting apparatus of claim 13, wherein a duty ratio of the quasi square-wave AC power at the fundamental frequency component has a value allowing a power ratio of the quasi square-wave AC power at the fundamental frequency component to be greater than a power ratio of square-wave AC power at the fundamental frequency component when a duty ratio of the square-wave AC power is 50%.

15. The wireless power transmitting apparatus of claim 12, wherein a duty ratio of the quasi square-wave AC power at the fundamental frequency component has a value allowing a power ratio of the quasi square-wave AC power at the fundamental frequency component to be greater than a power ratio of square-wave AC power at the fundamental frequency component when a duty ratio of the square-wave AC power is 50%.

16. The wireless power transmitting apparatus of claim 15, wherein the duty ratio of the quasi square-wave AC power is in a range of 23% to 48%.