Inductive power receiver apparatus

• US 10,424,967 B2
• Filed: 04/10/2017
• Issued: 09/24/2019
• 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:
  US15/483,838
• Publication Number:
  US 20170222485A1
• Time in Patent Office: 897 Days
• 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 core;

two overlapping substantially coplanar coils magnetically associated with the core, the coils overlapping each other such that there is reduced mutual coupling between the coils; and

an apparatus configured to tune each coil and combine an output of each tuned coil to thereby provide power.

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 the coils are substantially completely magnetically decoupled.

4. A magnetic flux pad as claimed in claim 1 wherein the coils partially overlap.

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 permeable core, and a shielding is provided on another side of the core.

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 magnetic core.

10. Pick-up apparatus for an inductive power transfer system, the power supply apparatus comprising:

a magnetic flux pad for receiving a magnetic flux, the pad comprising magnetically permeable core, two substantially flat overlapping coils magnetically associated with the core, wherein an overlap between the coils is such that there is reduced mutual coupling between the coils; 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.

11. Pick-up apparatus as claimed in claim 10 further comprising a switch to regulate the power available at the output.

12. Pick-up apparatus as claimed in claim 10 further comprising a detector to detect alignment of the magnetic flux pad of the pick-up with a transmitter flux pad.

13. 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;

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

providing apparatus configured to tune each coil independently.

14. A method as claimed in claim 13 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.