Wireless resonance coupled energy transmission

• US 9,577,714 B2
• Filed: 01/22/2014
• Issued: 02/21/2017
• Est. Priority Date: 02/08/2013
• Status: Active Grant

• Current Assignee: Markus Rehm
• Original Assignee: Markus Rehm
• Inventors: Rehm, Markus
• Primary Examiner(s): Wong, Albert
• Application Number:
  US13/999,134
• Publication Number:
  US 20140225458A1
• Time in Patent Office: 1,126 Days
• Field of Search: 320/108
• US Class Current: 1/1
• CPC Class Codes: H02J 50/05 using capacitive coupling
• 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 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: H02M 1/36 Means for starting or stopping converters
• CPC Class Codes: H02M 7/4815 Resonant converters H02M7/4811 and H02M7/4826 take precedence
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/263 Multiple coils at either side
• CPC Class Codes: H04B 5/75 for isolation purposes
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

In a first aspect of the present invention, a wireless power transmission link is proposed, which while substantially maintaining resonant coupling condition (resonance frequency of the source resonant circuit is substantially equal to the resonance frequency of the load resonant circuit) detects a coupling condition of the wireless power transmission link.

In a further aspect of the present invention, a wireless power transmission link is suggested, which while substantially maintaining resonant coupling condition (resonance frequency of the source resonant circuit is substantially equal to the resonance frequency of the load resonance circuit) controlling the operating state of the wireless power transmission link such, that the coupling condition of wireless power transmission link is substantially limited to the critical coupling condition.

Claims

1. A wireless electrical power transmission system based on nearfield coupled resonant circuits between a source unit and at least one load comprising:

at least one first capacitor and at least one first inductor forming at least one first resonant circuit in said source unit for emitting electrical power,

at least one second capacitor and at least one second inductor forming at least one a second resonant circuit, a resonance frequency of said at least one second resonant circuit being substantially equal to a resonant frequency of said at least one first resonant circuit, for receiving at least a part of the electrical power emitted by said at least one first resonant circuit and for delivering the at least a part of the electrical power to said at least one load,

at least one detector for detecting a coupling condition of said at least one first and second resonant circuits, and

at least one controller for controlling power transmission between said source unit and said at least one load, wherein said power transmission is at least one of interrupted, minimized and continued at a different emitted frequency, responsive to at least one of a detected critical- and overcritical coupling condition of said at least one first- and second resonant circuits.

2. A wireless electrical power transmission system according to claim 1, further comprising:

at least one power control loop for controlling the transmitted power from said source unit to said at least one load when said at least one of said critical and overcritical coupling condition is not detected.

3. A wireless electrical power transmission system according to claim 1, wherein a detector is responsive to a period or frequency of at least one of said at least one first and second resonant circuits to detect at least one of said critical and overcritical coupling condition.

4. A wireless electrical power transmission system according to claim 1, further comprising:

a frequency generator control loop for driving said at least one first resonant circuit at its resonance frequency.

5. A wireless electrical power transmission system according to claim 1, further comprising:

at least one third inductor or at least one third capacitor for controlling the resonance frequency of said at least one first resonant circuit, wherein said third inductor or said third capacitor is coupled to said at least one first resonant circuit by at least one switch for a controllable coupling interval, said controllable coupling interval being smaller than a voltage or current period in said at least one first resonant circuit.

6. A wireless electrical power transmission system according to claim 5, wherein said at least one third inductor or at least one third capacitor for controlling the resonance frequency of said at least one first resonant circuit is part of a large signal VCO included in a phase control loop for controlling a frequency of said emitted electrical power.

14. A wireless electrical power transmission system according to claim 1, further comprising:

at least two detectors for detecting a coupling condition of said at least one first and second resonant circuits, wherein said at least two detectors have different response times for detecting a coupling condition of said at least one first and second resonant circuits.

7. A method to control power transmission over an electrical wireless power transmission link based on a nearfield coupled resonant circuits comprising at least one first and at least one second resonant circuit which have substantially a same resonance frequency, said method comprising:

a) transmitting power from a source unit to at least one load via said nearfield coupled resonant circuits,

b) detecting at least one coupling condition of said wireless power transmission link, wherein said transmitted power is responsive to at least one of a detected critical- and overcritical coupling condition, and at least one of;

c1) disables said transmitting power,

c2) minimizes said transmitting power, and

c3) continues said transmitting power at a different transmission frequency.

8. The method according to claim 7, further comprising:

d) controlling said transmitting power from said source unit to said at least one load by a power control loop.

9. The method according to claim 7, wherein said detecting includes:

generating said at least one of a detected critical- and overcritical coupling condition responsive to a period or frequency of at least one of said at least one first and second resonant circuits.

10. The method according to claim 7, further comprising:

e) resonance detecting a resonance frequency of at least one of said at least one first and second resonant circuits, and

f) driving said at least one of said at least one first and second resonant circuits at a resonance frequency responsive to said resonance detecting.

11. The method according to claim 7, further comprising:

g) coupling of at least one of an additional inductor or capacitor to at least one of said at least one first and second resonant circuits for a variable coupling interval, the variable coupling interval being smaller than a voltage- or current period in said resonant circuit.

12. The method according to claim 11, further comprising:

h) controlling the frequency of said wireless power transmission link by retuning said variable coupling interval in a large signal VCO which is part of a phase control loop.

13. The method according to claim 7, wherein said detecting is executed at least twice independently with at least two different time responses.

15. A wireless electrical power transmission system based on nearfield coupled resonant circuits comprising:

at least one first resonant circuit coupled to at least one second resonant circuit for transmitting power from at least one source to at least one load, wherein a resonance frequency of said first resonant circuit is substantially equal to a resonance frequency of said second resonant circuit,

at least one detector for detecting a coupling condition of said at least one first and second resonant circuits, and

at least one controller for controlling the power transmission between said at least one source and said at least one load, wherein said power transmission is at least one of interrupted, minimized and continued at a different emitted frequency, responsive to at least one of a detected critical and overcritical coupling.

16. The wireless electrical power transmission system according to claim 15, further comprising:

a frequency control loop for driving a least one of said at least one first and second resonant circuits at its resonance frequency.

17. The wireless electrical power transmission system according to claim 15, further comprising:

at least one resonance frequency control loop for controlling the resonance frequency of at least one of said at least one first and second resonant circuits, wherein at least a part of electrical power in said wireless electrical power transmission system is transmitted at said resonance frequency of said at least one of said at least one first and second resonant circuits.

18. The wireless electrical power transmission system according to claim 17, wherein said at least one resonance frequency control loop comprises:

at least one third inductor or at least one third capacitor for controlling the resonance frequency of at least one of said at least one first and second resonant circuits, wherein said third inductor or said third capacitor is coupled to at least one of said at least one first and second resonant circuits by at least one switch for a controllable coupling interval which is smaller than a voltage- or current period in at least one of said first and second resonant circuits.

19. The wireless electrical power transmission system according to claim 15, wherein a detector is responsive to a period or frequency of at least one of said at least one first and second resonant circuits to detect at least one of said critical- and overcritical coupling condition.

20. A wireless electrical power transmission system according to claim 15, further comprising:

at least two detectors for detecting a coupling condition of said at least one first and second resonant circuits, wherein said at least two detectors have different response times for detecting a coupling condition of said at least one first and second resonant circuits.