Energy transmission apparatus and method

• US 10,374,462 B2
• Filed: 11/28/2017
• Issued: 08/06/2019
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: LG Innotek Company Limited (LG Corporation)
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Bae, Su Ho, Lee, Ki Min
• Primary Examiner(s): Barnie, Rexford N
• Assistant Examiner(s): Inge, Joseph N
• Application Number:
  US15/824,683
• Publication Number:
  US 20180083492A1
• Time in Patent Office: 616 Days
• Field of Search: 307104
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/50 using additional energy repeaters between transmitting devices and receiving devices
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

An apparatus and method for wirelessly transmitting electromagnetic energy are provided. The apparatus includes a power source, a transmission unit, and a measurement unit. The power source supplies a power according to a certain frequency. The transmission unit receives the power to wirelessly transmit the received power through self resonance. The measurement unit measures a phase difference between a voltage and current of the transmission unit. The certain frequency is controlled according to the phase difference. Accordingly, the apparatus and method control only the frequency of the power supply when a resonance frequency is changed by the change of an ambient environment, thus enhancing energy transmission efficiency.

Claims

1. A wireless power transmitting apparatus comprising:

a power supply configured to generate AC power having a resonance frequency that is a first frequency when there is no object;

a transmitting coil configured to transmit wireless power to a wireless power receiving apparatus, based on the AC power; and

a measuring unit configured to sense an input impedance of the transmitting coil,

wherein the input impedance includes a real component and an imaginary component,

wherein when there is no object present to affect a magnetic field of the transmitting coil, resonance is generated by the AC power to have the resonance frequency such that the input impedance includes only the real component,

wherein when there is an object located on an energy transfer path such that the magnetic field of the transmitting coil is affected the object, the resonance frequency is changed to be a second frequency and to increase the imaginary component of the input impedance,

wherein the wireless power transmitting apparatus is configured;

to determine if the increased imaginary component of the input impedance is within a predetermined range, and

when the increased imaginary component of the input impedance is out of the predetermined range, to control the power supply to change the second frequency to be the resonance frequency such that the imaginary component of the input impedance is adjusted to be within the predetermined range.

2. The wireless power transmitting apparatus of claim 1, wherein the wireless power transmitting apparatus controls a resonance condition with the wireless power receiving apparatus.

3. The wireless power transmitting apparatus of claim 1, wherein the wireless power transmitting apparatus transmits the wireless power to a plurality of wireless power receiving devices of the wireless power receiving apparatus.

4. A wireless power transmitting method comprising:

generating, by a power supply, AC power having a resonance frequency that is a first frequency when there is no object;

transmitting wireless power to a wireless power receiving apparatus through a transmitting coil, based on the AC power;

sensing an input impedance of the transmitting coil, the input impedance including a real component and an imaginary component;

generating resonance by the AC power to have the resonance frequency such that the input impedance includes only the real component, when there is no object present to affect a magnetic field of the transmitting coil;

changing the resonance frequency to be a second frequency and to increase the imaginary component of the input impedance, when an object is located on an energy transfer path such that the magnetic field of the transmitting coil is affected by the object;

determining if the increased imaginary component of the input impedance is within a predetermined range; and

when the increased imaginary component of the input impedance is out of the predetermined range, controlling the power supply to change the second frequency to be the resonance frequency such that the imaginary component of the input impedance is adjusted to be within the predetermined range.

5. The method of claim 4, wherein the wireless power is transmitted to a plurality of wireless power receiving devices of the wireless power receiving apparatus.