CONTACTLESS POWER TRANSFER SYSTEM

• US 20140021795A1
• Filed: 09/23/2011
• Published: 01/23/2014
• Est. Priority Date: 09/23/2010
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: PowerbyProxi Limited (Apple Inc.)
• Inventors: Robertson, Daniel, Bhargava, Kunal, Mishriki, Fady, Ren, Saining Sunny, Walton, Robert, Lecias, Eugenio Sia Jr.
• Granted Patent: US 9,646,763 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H01F 38/18 Rotary transformers
• CPC Class Codes: H02J 50/10 using inductive coupling
• 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

Abstract

A contactless inductively coupled power transfer system is provided_including multiple pairs of power transmitter and power receiver coils and a power management module for controlling the supply of power to transmitter coils or the power supplied by the power receiver module to loads. The design is particularly suited for use in a wind turbine to supply power to the nacelle. The transmitter coils may be driven in phase at the same frequency or at different frequencies selected to avoid interaction between transmitter coils and the power transmitter module. The transmitter and receiver coils may be arranged in a traditional slip ring type configuration with adjacent coil pairs are physically spaced apart to avoid cross coupling with adjacent transmitter and receiver coil pairs shielded from each other. The power transmitter module may employ Zero Voltage Switching (ZVS).

Claims

1. A contactless near field inductively coupled power transfer system including:

a. one or more power transmitter coils;

b. a plurality of power receiver coils each inductively coupled in use to an associated power transmitter coil;

c. a power transmitter module for driving the power transmitter coils;

d. a power receiver module for supplying power received via the power receiver coils to a load; and

e. a power management module for controlling the supply of power to transmitter coils or the power supplied by the power receiver module to loads,

wherein the power management module controls;

the power transmitter module to distribute power to power transmitter coils based on transmitter side fault condition information;

or the power receiver module to distribute power loads based on receiver side fault condition information.

2. A power transfer system as claimed in claim 1 in which the power transmitter module is a single circuit driving all power transmitter coils.

3. A power transfer system as claimed in claim 2 wherein the power transmitter coils are driven in phase at the same frequency.

4. A power transfer system as claimed in claim 2 wherein the power transmitter coils are driven at different frequencies selected to avoid interference between power transmitter coils and the power transmitter module.

5. A power transfer system as claimed in claim 1 in which the power transmitter module includes multiple drive circuits driving respective power transmitter coils.

6. A power transfer system as claimed in claim 1 in which the power receiver module includes multiple receiver circuits driving respective power receiver coils.

7. A power transfer system as claimed in claim 5 wherein adjacent coil pairs are physically spaced apart to avoid cross coupling.

8. A power transfer system as claimed in claim 5 wherein the circuits are galvanically isolated.

9. A power transfer system as claimed in claim 5 wherein the circuits share a common ground.

10. A power transfer system as claimed in claim 5 wherein the power management module controls power distribution between drive circuits.

11. A power transfer system as claimed in claim 6 wherein the power management module controls power distribution between power receiver circuits.

12. A power transfer system as claimed in claim 1 wherein the power management module controls the power transmitter or receiver modules based on user specified power distribution.

13. A power transfer system as claimed in claim 1 including a sensor module for sensing operation of the system and supplying sensed information to the power management module.

14. A power transfer system as claimed in claim 13 wherein the sensor module senses transmitter side faults.

16. A power transfer system as claimed in claim 13 wherein the sensor module senses receiver side faults.

18. A power transfer system as claimed in claim 13 wherein the sensor module senses power demand of supplied loads.

19. A power transfer system as claimed in claim 1 wherein the power management module controls the power distribution module to utilise the smallest number of power transmitter coil and power receiver coil pairs possible to supply the required power to the receiver module.

20. A power transfer system as claimed claim 1 wherein adjacent power transmitter coil and power receiver coil pairs are shielded with a shield.

21. A power transfer system as claimed in claim 20 wherein the shield is formed from Litz wire.

22. A power transfer system as claimed claim 1 wherein the power transmitter and power receiver coils rotate with respect to each other.

23. A power transfer system as claimed claim 1 including a wireless communication link for transmitter information between transmitter and/or receiver and/or power management modules.

24. A power transfer system as claimed claim 1 wherein the power transmitter module employs Zero Voltage Switching (ZVS).

25. A power transfer system as claimed in claim 24 wherein at start up if there is stored resonant energy the power transmitter module follows the ZVS frequency of resonant energy stored.

26. A power transfer system as claimed in claim 24 wherein at start up if there is no stored resonant energy the power transmitter module briefly drives one or more transmission coil and after a delay follows the ZVS frequency of resonant energy stored.

27. A wind turbine including a power transfer system as claimed in claim 1.

15. (canceled)

17. (canceled)