Inductive power receiver apparatus

• US 9,620,281 B2
• Filed: 08/05/2011
• Issued: 04/11/2017
• Est. Priority Date: 08/06/2010
• Status: Active Grant

• Current Assignee: Auckland UniServices Limited (Auckland University)
• Original Assignee: Auckland UniServices Limited (Auckland University)
• Inventors: Covic, Grant Anthony, Budhia, Mickel Bipin
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Pham, Duc M
• Application Number:
  US13/814,542
• Publication Number:
  US 20130285463A1
• Time in Patent Office: 2,076 Days
• Field of Search: 307104
• CPC Class Codes: H01F 27/2823 Wires H01F27/2866 takes precedence
• CPC Class Codes: H01F 27/2885 with shields or electrodes shields or electrodes for pancake coils H01F27/2871; construction of electric or magnetic shields or screens H01F27/36
• CPC Class Codes: H01F 27/346 Preventing or reducing leakage fields using magnetic shields H01F27/36; using auxiliary windings H01F27/38
• 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 41/04 for manufacturing coils coils for transformer or inductances H01F27/28
• 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 50/10 using inductive 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 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

A magnetic flux pad (BPP) is provided for receiving magnetic flux. The pad may be used with an inductive power transfer system, and comprises a magnetically permeable core (4) and two substantially flat overlapping coils (2, 3) magnetically associated with the core (4).

Claims

1. A magnetic flux pad for receiving magnetic flux, the pad comprising a magnetically permeable material, and two coils magnetically associated with the magnetically permeable material, the coils overlapping each other so as to have minimal mutual coupling.

2. A magnetic flux pad as claimed in claim 1 and wherein magnetic properties of the coils are substantially the same.

3. A magnetic flux pad as claimed in claim 1 wherein there is substantially no mutual coupling between the coils.

4. A magnetic flux pad as claimed in claim 1 wherein the coils are substantially completely magnetically decoupled.

5. A magnetic flux pad as claimed in claim 1 wherein the coils are substantially flat.

6. A magnetic flux pad as claimed in claim 1 wherein the coils are provided on one side of the magnetically permeable material, and a shielding is provided on another side of the core magnetically permeable material.

7. A magnetic flux pad as claimed in claim 6 wherein the shielding comprises a shielding plate.

8. A magnetic flux pad as claimed in claim 7 wherein the shielding plate is made from aluminium or magnesium or other suitable material.

9. A magnetic flux pad as claimed in claim 1 wherein a dielectric cover is provided on a side of the coils opposite the magnetically permeable material.

10. A magnetic flux pad as claimed in claim 1 further comprising apparatus adapted to tune each coil and combine an output of each tuned coil to thereby provide power.

17. A magnetic flux pad as recited in claim 1, adapted for transfer of power over an air gap greater than substantially 100 mm.

18. A magnetic flux pad as recited in claim 1, adapted for transfer of power over an air gap between substantially 100-300 mm.

19. A magnetic flux pad as recited in claim 1, wherein a dimension of each coil extends beyond the magnetic permeable material.

20. A magnetic flux pad as recited in claim 1, wherein the coils extend beyond the magnetic permeable material.

11. Pick-up apparatus for an inductive power transfer system, the pick-up apparatus comprising:

a magnetic flux pad for receiving a magnetic flux, the pad comprising a magnetically permeable material, two coils magnetically associated with the magnetic permeable material, the coils overlapping each other so as to have minimal mutual coupling; and

apparatus adapted to tune each coil and combine an output of each tuned coil to provide power to an output of the pick-up.

12. Pick-up apparatus as claimed in claim 11 further comprising a switch to regulate the power available at the output.

13. Pick-up apparatus as claimed in claim 11 further comprising a detector to detect alignment of the magnetic flux pad of the pick-up with a transmitter flux pad.

16. A magnetic flux pad as claimed in claim 13, wherein the detector is adapted to sense a short circuit current or an open circuit voltage of the coils.

14. A method for providing an IPT magnetic flux receiver pad having a plurality of coils in which there is no mutual magnetic coupling between the coils, the method comprising:

overlapping the coils; and

varying the overlap between the coils such that an overlap position is achieved whereby there is substantially no mutual coupling between the coils.

15. A method as claimed in claim 14 wherein absence of mutual coupling is detected by detecting when an open circuit voltage induced in one of the coils by energisation of the other coil is minimised.