Wireless power transmission apparatus and method

• US 10,193,387 B2
• Filed: 03/05/2015
• Issued: 01/29/2019
• Est. Priority Date: 03/07/2014
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Jaesung, Park, Jinmoo, Lee, Jihyun
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): Inge, Joseph
• Application Number:
  US15/123,836
• Publication Number:
  US 20170018965A1
• Time in Patent Office: 1,426 Days
• Field of Search: 307104
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment

Abstract

A wireless power transmission device is disclosed. The wireless power transmission device, which is a medium-power wireless power transmission device that transmits power to a low-power wireless power reception device or a medium-power wireless power reception device, includes: a power conversion unit that converts electrical energy to a power signal; and a communications and control unit that communicates with the wireless power reception device and controls power transfer, the power conversion unit including: an inverter that converts DC input to an AC waveform that drives a resonant circuit; a primary coil that creates a magnetic field; and a current sensor that monitors the current in the primary coil, wherein the inverter operates in a full-bridge mode that drives a plurality of bridges or in a half-bridge mode that drives a single bridge.

Claims

1. A wireless power transfer device, which is a medium-power wireless power transfer device that transfers power to a low-power wireless power reception device or a medium-power wireless power reception device, the wireless power transfer device comprising:

a power conversion unit that converts electrical energy to a power signal; and

a communications and control unit that communicates with the wireless power reception device and controls power transfer,

the power conversion unit comprising;

an inverter that converts DC input to an AC waveform that drives a resonant circuit;

a primary coil that generates a magnetic field;

a shield material aligned with the primary coil; and

a current sensor that monitors current in the primary coil,

wherein the primary coil has a rectangular shape with a single layer of which a number of turns is 12, and consists of 105 strands Litz wire of which the diameter is 0.08 mm,

wherein the shield material is at least 1.5 mm thick and extends at least 2.5 mm beyond the outside of the primary coil,

wherein the primary coil and the shield material have a self-inductance 10.0 μ

H, and

wherein the inverter operates in a full-bridge mode or in a half-bridge mode, the initial operation mode is set to the half-bridge mode, and if a detected wireless power reception device is the medium-power wireless power reception device, the communications and control unit changes the inverter operation mode from the half-bridge mode to the full-bridge mode alter receiving a control error packet from the wireless power reception device.

2. The wireless power transfer device of claim 1, wherein the control error packet indicates a control error value that the wireless power reception device calculates using a desired control point and an actual control point.

3. The wireless power transfer device of claim 1, wherein, when the inverter operation mode is changed from the half-bridge mode to the full-bridge mode, an operating frequency in the initial operation mode is maintained, and a duty cycle is changed.

4. The wireless power transfer device of claim 1, wherein the low-power wireless power reception device supports power reception of up to about 5 watt and the medium-power wireless power reception device supports power reception of up to about 15 watt.

5. The wireless power transfer device of claim 1, wherein the inverter comprises a first bridge and a second bridge, the inverter operates in the full-bridge mode if driving pulse signals are applied to the first bridge and the second bridge, and the inverter operates in the half-bridge mode if a driving pulse signal is applied to the first bridge and no driving pulse signal is applied to the second bridge.