Bi-plane wireless power transmission pad

Abstract

An apparatus includes a first charging coil with one or more conductors arranged in a first winding pattern, a second charging coil with one or more conductors arranged in a second winding pattern, and a ferrite structure with a main section with a top side, a first side section and a second side section. A portion of the top side of the main section is adjacent to a portion of the bottom side of the first side section and the second side section. A portion of the first and second charging coils are positioned adjacent to the top side of the main section interior in between the first and second side sections. A portion of the first charging coil is adjacent to the bottom of the first side section. A portion of the second charging coil is adjacent to the bottom of the second side section.

What is claimed is: 
     
       1. An apparatus comprising:
 a first charging coil comprising one or more conductors arranged in a first winding pattern; 
 a second charging coil comprising one or more conductors arranged in a second winding pattern; and 
 a multi-level ferrite structure comprising a main section at a first level, the main section comprising a top side along a plane, a first side portion and second side portion, a first side section at a second level and a second side section at the second level, the first side section and the second side section each comprising a bottom side positioned along the plane, 
 wherein the a first side portion of the top side of the main section is adjacent to a portion of the bottom side of the first side section along the plane and the a second side portion of the top side of the main section is adjacent to a portion of the bottom side of the second side section along the plane, and 
 wherein a portion of the first charging coil and a portion of the second charging coil are positioned adjacent to the top side of the main section in the first level along the plane and interior to where the first side section and the second side section are adjacent to the top side of the main section, a portion of the first charging coil is adjacent to the bottom side of the first side section in the second section along the plane and a portion of the second charging coil is adjacent to the bottom side of the second side section in the second section along the plane, 
 wherein a signal injected in the first and second charging coils generates an electromagnetic field radiating in a direction away from the top side of the main section. 
 
     
     
       2. The apparatus of  claim 1 , wherein the main section is magnetically coupled to the first side section and to the second side section. 
     
     
       3. The apparatus of  claim 1 , further comprising a space between the portion of the first charging coil and the portion of the second charging coil located adjacent to the top side of the main section. 
     
     
       4. The apparatus of  claim 1 , wherein the main section, the first side section and the second side section of the ferrite structure are separate and wherein the top side of the main section is in contact with the bottom side of to the first side section and with the bottom side of the second side section. 
     
     
       5. The apparatus of  claim 1 , wherein the portion of the first charging coil and the portion of the second charging coil adjacent to the top side of the main section are wound in a spiral pattern in a plane parallel to the top side of the main section. 
     
     
       6. The apparatus of  claim 1 , wherein the ferrite structure comprises a first edge and a second edge, the first and second edge edges located distal to a plane bisecting the main section, the first side section and the second side section, the first charging coil and the second charging coil extend extending past the first and second edges of the ferrite structure. 
     
     
       7. The apparatus of  claim 1 , wherein the ferrite structure further comprises a plurality of notches, each notch accommodating a portion of one of the first charging coil and the second charging coil during a transition between the main section and one of the first side section and the second side section. 
     
     
       8. The apparatus of  claim 1 , wherein the main section is joined to the first side section and the second side section. 
     
     
       9. The apparatus of  claim 1 , wherein the portion of the first charging coil adjacent to the bottom side of the first side section is wound to group the one or more conductors in a pattern that minimizes one or more of conductor length and distance from a center point of the main section between the first charging coil and the second charging coil. 
     
     
       10. The apparatus of  claim 1 , wherein the one or more conductors of the first charging coil and the one or more conductors of the second charging coil each comprise two coils wound in a parallel pattern wherein a first coil of a charging coil of the first or second charging coils is wound adjacent to a second coil of the charging coil. 
     
     
       11. The apparatus of  claim 1 , wherein each of the one or more conductors of the first charging coil and the second charging coil are stacked in layers over the main section, each layer is in a plane parallel to the top side of the main section. 
     
     
       12. The apparatus of  claim 1 , wherein the first and second charging coils and the ferrite structure comprise a first pad section and further comprising a second pad section, the second pad section comprising two or more additional charging coils and an additional ferrite structure arranged the same as the first pad section, wherein the first pad section and the second pad section are arranged to form a charging pad. 
     
     
       13. The apparatus of  claim 1 , wherein the apparatus is part of a primary pad of a wireless power transfer system and further comprising an inverter connected to the first and second charging coils, the inverter injecting the signal in the first and second charging coils. 
     
     
       14. The apparatus of  claim 13 , further comprising a secondary pad magnetically coupled to the primary pad, the secondary pad converting energy from the electromagnetic field into electrical energy, and further comprising a secondary circuit connected to the secondary pad, wherein the secondary circuit receives the electrical energy from the secondary pad and conditions the electrical energy for use by a load. 
     
     
       15. An apparatus comprising: The apparatus of  claim 1 , 
 a first charging coil comprising one or more conductors arranged in a first winding pattern; 
 a second charging coil comprising one or more conductors arranged in a second winding pattern; and 
 a multi-level ferrite structure comprising a main section at a first level, the main section comprising a top side along a plane, a first side portion and second side portion, a first side section at a second level and a second side section at the second level, the first side section and the second side section each comprising a bottom side positioned along the plane, wherein the main section is magnetically coupled to the first side section and to the second side section, and  
 wherein the bottom side of the main section is offset from the bottom side of the first side section and from the second side section, and 
 wherein a portion of the first charging coil and a portion of the second charging coil are positioned adjacent to the top side of the main section in the first level along the plane and interior to where the first side section and the second side section are adjacent to the top side of the main section, a portion of the first charging coil is adjacent to the bottom side of the first side section in the second section along the plane and a portion of the second charging coil is adjacent to the bottom side of the second side section the second section along the plane, 
 wherein a signal injected in the first and second coils generates an electromagnetic field radiating in a direction away from the top side of the main section. 
 
     
     
       16. The apparatus of  claim 15 , wherein the offset is at least a thickness of one or more of the first charging coil and the second charging coil, the thickness measured in a direction perpendicular to the bottom side of one or more of the first side section and the second side section. 
     
     
       17. The apparatus of  claim 15 , wherein the portion of the first charging coil and the portion of the second charging coil adjacent to the top side of the main section are wound in a spiral pattern in a the plane parallel to the top side of the main section. 
     
     
       18. The apparatus of  claim 15 , wherein the ferrite structure comprises a first edge and a second edge, the first and second edges located distal to a plane bisecting the main section, the first side section and the second side section, the first charging coil and the second charging coil extend extending past the first and second edges of the ferrite structure. 
     
     
       19. A system for wireless power transfer, the system comprising:
 a first charging coil comprising one or more conductors arranged in a first winding pattern; 
 a second charging coil comprising one or more conductors arranged in a second winding pattern; 
 a multi-level ferrite structure comprising a main section at a first level, the main section comprising a top side along a plane, a first side portion and second side portion, a first side section at a second level and a second side section at the second level, the first side section and the second side section each comprising a bottom side positioned along the plane, 
 wherein the first side portion of the top side of the main section is adjacent to a portion of the bottom side of the first side section along the plane and the second side portion of the top side of the main section is adjacent to a portion of the bottom side of the second side section along the plane, and 
 wherein a portion of the first charging coil and a portion of the second charging coil are positioned adjacent to the top side of the main section in the first level along the plane and interior to where the first side section and the second side section are adjacent to the top side of the main section, a portion of the first charging coil is adjacent to the bottom side of the first side section in the second section along the plane and a portion of the second charging coil is adjacent to the bottom side of the second side section in the second section along the plane, wherein a signal injected in the first and second charging coils generates an electromagnetic field radiating in a direction away from the top side of the main section; and 
 an inverter connected to the first and second charging coils, the inverter injecting a the signal in the first and second charging coils, wherein the injected signal generates an electromagnetic field radiating in a direction away from the top side of the main section. 
 
     
     
       20. The system of  claim 19 , wherein the first charging coil, the second charging coil and the ferrite structure comprise a primary pad and further comprising a secondary pad magnetically coupled to the primary pad, the secondary pad converting energy from the electromagnetic field into electrical energy, and further comprising a secondary circuit connected to the secondary pad, wherein the secondary circuit receives the electrical energy from the secondary pad and conditions the electrical energy for use by a load. 
     
     
       21. An apparatus comprising:
 a multi-level ferrite structure comprising:
 a main section comprising a top side along a plane; 
 a first side section; and 
 a second side section, a bottom side of the first and second side sections positioned along the plane, wherein a portion of the bottom side of the first and second side sections are adjacent to the top side of the main section at opposite ends of the main section; 
   a first charging coil; and   a second charging coil,   wherein a portion of conductors of the first charging coil and the second charging coil are adjacent to the top side of the main section, a portion of the first charging coil is adjacent to the bottom side of the first side section along the plane, and a portion of the second charging coil is adjacent to the bottom side of the second side section,   wherein a signal injected in the first and second charging coils generates an electromagnetic field radiating in a direction away from the top side of the main section.   
     
     
       22. The apparatus of  claim 21 , wherein the main section is magnetically coupled to the first side section and to the second side section. 
     
     
       23. The apparatus of  claim 21 , further comprising a space between the portion of the first charging coil and the portion of the second charging coil located adjacent to the top side of the main section. 
     
     
       24. The apparatus of  claim 21 , wherein the main section, the first side section and the second side section of the ferrite structure are separate and wherein the top side of the main section is in contact with the bottom side of the first side section and with the bottom side of the second side section. 
     
     
       25. The apparatus of  claim 24 , wherein the portion of the first charging coil and the portion of the second charging coil adjacent to the top side of the main section are wound in a spiral pattern in a plane parallel to the top side of the main section. 
     
     
       26. The apparatus of  claim 21 , wherein the ferrite structure further comprises a plurality of notches, each notch accommodating a portion of one of the first charging coil and the second charging coil during a transition between the main section and one of the first side section and the second side section. 
     
     
       27. The apparatus of  claim 21 , wherein the portion of the first charging coil adjacent to the bottom side of the first side section is wound to group the one or more conductors in a pattern that minimizes one or more of conductor length and distance from a center point of the main section between the first charging coil and the second charging coil. 
     
     
       28. The apparatus of  claim 21 , the first charging coil is mirror image of the second charging coil. 
     
     
       29. The apparatus of  claim 21 , wherein the multi-level ferrite structure, first charging coil and second charging coil comprise a primary pad configured to wirelessly transfer power to secondary pad. 
     
     
       30. The apparatus of  claim 29 , wherein the primary pad is stationary and the secondary pad is on a vehicle and provides power to a battery that provides power to the vehicle.