Inductive power transfer apparatus
View Patent ↗A magnetic flux pad for generating or receiving magnetic flux has two pole areas ( 11, 12 ), a permeable core ( 14 ) and a coil ( 16 ) wound about the core. The pad allows useable flux to be generated at a significant height above a surface of the pad.
1. A magnetic flux pad for generating or receiving magnetic flux, the pad having a front face and a back face and comprising:
a magnetically permeable material having two ends from which magnetic flux is directed into an area beyond the front face of the pad;
two separated solenoidal windings connected magnetically in series and magnetically associated with the permeable material; and
a magnetic flux repelling member adjacent to the back face.
2. A magnetic flux pad as claimed in claim 1 wherein the magnetic flux repelling member directs magnetic flux into an area beyond the front face of the pad.
3. A magnetic flux pad as claimed in claim 1 further comprising a further flux repelling member located between the ends and on a side of the permeable material adjacent to the front face of the pad.
4. A magnetic flux pad as claimed in claim 1 wherein the windings are connected electrically in parallel.
5. A magnetic flux pad as claimed in claim 1 wherein each end comprises a plurality of fingers.
6. An IPT system including a magnetic flux pad or IPT power transfer pad according to claim 1 .
7. An IPT system as claimed in claim 6 wherein the system supplies power to an electric vehicle.
8. A magnetic flux pad as claimed in claim 1 wherein the permeable material is elongate and each end of the core comprises a pole area.
9. A magnetic flux pad as claimed in claim 1 wherein each winding is provided adjacent to a pole area.
10. A magnetic flux pad as claimed in claim 1 wherein each winding provides substantially the same flux linkages.
11. A magnetic flux pad having a front face and a back face for generating a magnetic flux in a space beyond the front face of the pad, the pad comprising:
two pole areas for sending or receiving flux;
a magnetically permeable core magnetically connecting the pole areas;
a winding magnetically associated with the core;
a flux repelling member provided adjacent to a rear face; and
wherein each pole area includes a plurality of fingers.
12. An IPT system including a magnetic flux pad or IPT power transfer pad according to claim 11 .
13. A magnetic flux pad as claimed in claim 11 wherein each winding provides substantially the same flux linkages.
14. A magnetic flux pad as claimed in claim 11 further comprising a further flux repelling member located adjacent to the front face of the pad.
15. A magnetic flux pad as claimed in claim 11 wherein the winding comprises two windings.
16. A magnetic flux pad as claimed in claim 15 wherein the windings are connected electrically in parallel.
17. A magnetic flux pad as claimed in claim 15 wherein the windings are connected magnetically in series.
18. A magnetic flux pad as claimed in claim 15 wherein the windings are separated.
19. A magnetic flux pad as claimed in claim 18 wherein each winding is provided adjacent to a pole area.
20. A magnetic flux pad as claimed in claim 15 wherein each winding provides substantially the same flux linkages.
21. A magnetic flux pad as claimed in claim 11 wherein the cores is elongate and the pole areas are at either end of the core.
22. An IPT system including a first magnetic flux pad or IPT power transfer pad for connection to a power supply and a second magnetic flux pad or IPT power transfer pad for connection to a load, the first and second magnetic flux pads or IPT power pads having one or more windings with a same number of turns, and wherein the number of turns is selected dependent on a required operating frequency.
23. An IPT system as claimed in claim 22 wherein the system supplies power to an electric vehicle.