Inductive power transfer unit, a system for inductive power transfer and a method of communicating

Abstract

The invention relates to an inductive power transfer unit, wherein the inductive power transfer unit includes at least one winding structure and at least one flux guiding means, wherein the inductive power transfer unit further includes at least one antenna element, wherein at least one portion of the at least one flux guiding means is a part of the antenna element. The invention further relates to a system for inductive power transfer and a method of communicating.

Claims

1. An inductive power transfer unit for inductive power transfer to a vehicle, wherein the inductive power transfer unit comprises at least one winding structure and at least one flux guiding means, wherein the inductive power transfer unit further comprises at least one antenna element, wherein at least one portion of the at least one flux guiding means is a part of the at least one antenna element, wherein the inductive power transfer unit comprises an arrangement of multiple flux guiding means, wherein the arrangement of flux guiding means comprises multiple rows of flux guiding elements, wherein the rows of flux guiding elements are arranged adjacent to each other, wherein a flux guiding means is designed as a bar, wherein the at least one antenna element is wound around at least one section of at least one flux guiding means, wherein the at least one winding structure comprises multiple subwinding structures, wherein successive subwinding structures of the at least one winding structure are arranged adjacent to one another along a longitudinal axis of the at least one winding structure, wherein the at least one winding structure is configured to generate or receive an electromagnetic field for the inductive power transfer, wherein the at least one flux guiding means is configured to guide a magnetic flux of the electromagnetic field generated or received by the at least one winding structure, wherein at least one section of the flux guiding means extends into a volume or area enclosed by the multiple subwinding structures, and wherein the at least one antenna element is configured to separate from the at least one winding structure and is an element for receiving or transmitting a communication signal.

2. The inductive power transfer unit of claim 1, wherein the at least one antenna element is wound around at least one section of multiple flux guiding means.

3. The inductive power transfer unit of claim 1, wherein at least one part of the at least one antenna element is arranged within an area enclosed by the at least one winding structure in a common plane of projection and/or at least one part of the at least one antenna element is arranged outside an area enclosed by the at least one winding structure in a common plane of projection.

4. The inductive power transfer unit of claim 1, wherein the at least one antenna element provides a low-frequency antenna.

5. The inductive power transfer unit of claim 1, wherein the at least one antenna element provides a transmitter or a receiver for a unidirectional communication.

6. The inductive power transfer unit of claim 1, wherein the inductive power transfer unit is a secondary unit of a system for inductive power transfer.

7. The inductive power transfer unit of claim 1, wherein the inductive power transfer unit is a primary unit of a system for inductive power transfer.

8. The inductive power transfer unit of claim 1, wherein the inductive power transfer unit further comprises at least one communication unit for a bidirectional communication.

9. The inductive power transfer unit of claim 1, wherein the inductive power transfer unit further comprises at least one control unit for operating the at least one antenna element.

10. The inductive power transfer unit of claim 1, wherein the inductive power transfer unit further comprises a compensating element for at least partially compensating a voltage which is induced in the at least one antenna element by the electromagnetic field for inductive power transfer.

11. A system for inductive power transfer, wherein the system comprises a primary unit and a secondary unit, wherein at least one of the primary unit and the secondary unit is designed according to claim 1.

12. The system according to claim 11, wherein the primary unit comprises two antenna elements and the secondary unit comprises three antenna elements.

13. The system according to claim 11, wherein the secondary unit comprises one antenna element and the primary unit comprises two antenna elements.

14. A method of communication between a primary unit and a secondary unit of a system for inductive power transfer, wherein at least one of the primary unit and the secondary unit is designed according to claim 1, wherein one of the primary and secondary units at least one of transmits a signal to and receives a signal from the other of the primary and secondary units by the at least one antenna element.

15. The method of claim 14, wherein at least one of a position and an orientation of a secondary winding structure relative to a primary winding structure is determined depending on at least one of the transmitted signal and the received signal.

16. The method of claim 15, wherein at least one of the position and the orientation of the secondary winding structure relative to the primary winding structure is determined depending on a signal strength of the received signal.

17. The method of claim 14, wherein a voltage induced in the at least one antenna element by the electromagnetic field for power transfer is compensated at least partially.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be described with reference to the attached figures. The figures show:

(2) FIG. 1 a schematic top view on an inductive power transfer unit according to the invention,

(3) FIG. 2 a schematic side view of the inductive power transfer unit shown in FIG. 1,

(4) FIG. 3 a schematic top view of an inductive power transfer unit according to another embodiment,

(5) FIG. 4 a schematic side view of the inductive power transfer unit shown in FIG. 3,

(6) FIG. 5 a schematic top view of an inductive power transfer unit according to another embodiment,

(7) FIG. 6 a schematic side view of the inductive power transfer unit shown in FIG. 5,

(8) FIG. 7 a schematic top view on an inductive power transfer unit according to another embodiment of the invention,

(9) FIG. 8 a schematic side view of the inductive power transfer unit shown in FIG. 7.

(10) FIG. 9 a schematic block diagram of a system for inductive power transfer according to the invention.

DESCRIPTION OF THE INVENTION

(11) In the following, the same reference numerals denote elements with the same or similar technical features.

(12) FIG. 1 shows a schematic top view on an inductive power transfer unit 1. The inductive power transfer unit 1 comprises a winding structure 2, wherein the winding structure 2 comprises a first subwinding 2a and a second subwinding 2b. The winding structure 2 extends along a longitudinal axis x.

(13) It is shown that the first subwinding 2a provides a rectangular-shaped loop. Also the second subwinding 2b provides a rectangular-shaped loop. The first subwinding 2a encloses an inner area 3a. The second subwinding 2b encloses an inner area 3b. Between the two subwindings 2a, 2b, an interspace area 4 is provided. The interspace area 4 is arranged between a front end section 5a of the first subwinding and a rear end section 6b of the second subwinding. Further indicated are a front end section 6a of the second subwinding and a rear end section 5b of the first subwinding 2a. The front and rear end sections 5a, 5b, 6a, 6b extend parallel to a lateral axis y. Further shown are longitudinal sections 7a, 7b. An electrical connection of the two subwindings 2a, 2b is schematically shown by a longitudinal section 8 connecting the first subwinding 2a and the second subwinding 2b. A section of the winding structure 2 can be provided by a lithe wire or a conductor.

(14) Further, the inductive power transfer unit 1 comprises multiple ferrite bars 9, wherein the ferrite bars 9 extend along the longitudinal direction x. Shown are two ferrite bars 9 which are arranged adjacent to each other along the lateral direction y, wherein the adjacent ferrite bars 9 are spaced apart from another with a non-zero distance. One ferrite bar 9 provides one row. The ferrite bars 9 are designed as ferrite plates.

(15) Further, with respect to a vertical direction z (see FIG. 2) a ferrite bar 9 is arranged above the winding structure 2. In particular, the ferrite bar 9 is arranged above the area 3a enclosed by the first subwinding 2a, the interspace area 4 and the inner area 3b enclosed by the second subwinding 2b. It is shown that the ferrite bar 9 has a length along the longitudinal axis x which is smaller than the length of the winding structure 2.

(16) Further shown is an antenna element 10, wherein a winding structure 11 of the antenna element 10 is wound around one section of one of the ferrite bars 9. In particular, the winding structure 11 is wound around a section of the ferrite bar 9 which is located above the inner area 3b enclosed by the second subwinding structure 2b.

(17) FIG. 2 shows a schematic side view of the inductive power transfer unit 1 shown in FIG. 1. It can be seen that the complete ferrite bar 9 is arranged above the winding structure 2. Further, the inductive power transfer unit 1 can in particular be a secondary unit of a system for inductive power transfer 12 (see FIG. 9).

(18) FIG. 3 shows a schematic top view on an inductive power transfer unit 1 according to another embodiment of the invention. The inductive power transfer unit 1 shown in FIG. 3 is designed similar to the inductive power transfer unit 1 shown in FIG. 1 and FIG. 2. In contrast to the embodiment shown in FIG. 1 and FIG. 2, the inductive power transfer unit 1 comprises a compensating winding structure 12. The compensating winding structure 12 has a rectangular shape, wherein terminal or end sections of the compensating winding structure 12 are connected to terminal or end sections of the winding structure 11 of the antenna element 10. An area 13 enclosed by the compensating winding structure 12 is arranged above the inner area 3a enclosed by the first subwinding 2a, above the interspace area 4 and the inner area 3b enclosed by the second subwinding 2b. It is shown that the area 13 is arranged above a portion of the inner area 3a enclosed by the first subwinding 2a which is larger than the portion of the inner area 3b covered by the compensating winding structure 12. As a result, the compensating winding structure 12 is arranged and designed such that the electromagnetic field for inductive power transfer which is generated or received by the winding structure 2 induces a voltage in the compensating winding structure 12 which is equal to the voltage induced in the winding structure 11 of the antenna element 10 or differs not more than a predetermined amount from said voltage.

(19) Another differing feature to the embodiment shown in FIG. 1 and FIG. 2 is that the winding structure 11 of the antenna element is wound around multiple ferrite bars 9 of a row 13 of ferrite bars 9, wherein the row 13 comprises three ferrite bars 9. A first section of the winding structure 11 is wound around a section of a first ferrite bar 9a which is arranged above the inner area 3a enclosed by the first subwinding 2a. A second section of the winding structure 11 of the antenna element 10 is wound around a section of a second ferrite bar 9b which is arranged above the interspace 4. Finally, a third section of the winding structure 11 of the antenna element 10 is wound around a section of a third ferrite bar 9c which is arranged above the inner area 3b enclosed by the second subwinding 2b.

(20) FIG. 4 shows a schematic side view of the inductive power transfer unit 1 shown in FIG. 3. Shown is a row 13 of three ferrite bars 9. With respect to the vertical direction z, a first ferrite bar 9a and a third ferrite bar 9c are arranged at a lower position than a second ferrite bar 9b. A rear end section of the second ferrite bar 9b is arranged above a front end section of the first ferrite bar 9a. Further, a rear end section of the third ferrite bar 9c is arranged under a front end section of the second ferrite bar 9b. Thus, the second ferrite bar 9b overlaps the first and the third ferrite bar 9a, 9c partially. In summary, a recess 14 is provided by the row 13 of ferrite bars 9a, 9b, 9c. Within the recess 14, the front section 5a and the rear section 6b of the first and second subwinding 2a, 2b are arranged.

(21) Further shown is that the first ferrite bar 9a is arranged within the inner area 3a enclosed by the first subwinding 2a. As the first section of the winding structure 11 of the antenna element is wound around the first ferrite bar 9a, it is also arranged in inner area 3a of the first subwinding 2a. Correspondingly, the third ferrite bar 9c is arranged in the inner area 3b of the second subwinding 2b. As a result, the third section of the winding structure 11 of the antenna element 10 is also arranged in the inner area 3b of the second subwinding 2b. The second ferrite bar 9b is arranged above the interspace area 4. Thus, a second section of the winding structure 11 of the antenna element 10 is also arranged above the interspace area 4.

(22) FIG. 5 and FIG. 6 show a schematic top and side view on an inductive power transfer unit 1 according to another embodiment of the invention. The inductive power transfer unit 1 shown in FIG. 5 is designed similar to the embodiments shown in FIG. 1 and FIG. 2. In contrast to the embodiments shown in FIG. 1 and FIG. 2, the winding structure 11 of the antenna element 10 is completely arranged above the interspace area 4.

(23) FIG. 7 and FIG. 8 show a schematic top view and a schematic side view of an inductive power transfer unit 1 in another embodiment of the invention. The inductive power transfer unit 1 shown in FIG. 7 and FIG. 8 are designed similar to the embodiment shown in FIG. 3 and FIG. 4. In contrast to the embodiment shown in FIG. 3 and FIG. 4, the inductive power transfer unit 1 has no compensating winding structure 12.

(24) However, different sections of the winding structure 11 of the antenna element 10 are wound around different ferrite bars 9a, 9b, 9c of a row 13 of ferrite bars 9a, 9b, 9c.

(25) FIG. 9 shows a schematic block diagram of a system 12 for inductive power transfer. The system 14 comprises a primary unit 15 and a secondary unit 16. The primary unit 15 can be installed in or on a ground, in particular on a surface of a route. Thus, the primary unit 15 can also be referred to as wayside unit. The secondary unit 16 can be installed on a vehicle.

(26) The primary unit 15 comprises two antenna elements 10 which are arranged at different positions. Further, the primary unit 15 comprises a communication unit 17 for an ultrahigh frequency bidirectional communication. Not shown are a primary winding structure and other elements of the primary unit 15.

(27) The secondary unit 16 comprises three antenna elements 10 and a bidirectional UHF communication unit 17.

(28) A position of the primary-sided antenna elements 10 relative to a primary winding structure is known. Further known is a position and orientation of the secondary-sided antenna elements 10 relative to the secondary winding structure.

(29) To determine if the secondary winding structure is correctly aligned relative to the primary winding structure, the primary-sided antenna elements can transmit a signal with a constant signal strength. This means that the primary-sided antenna elements can be operated with a constant transmitting power. The constant signal strength can be communicated to the secondary unit 16 via the primary-sided communication unit 17 of the primary unit 15.

(30) The three secondary-sided antenna elements 10 receive the signals transmitted by the primary-sided antenna elements 10. A control unit 18 of the secondary unit 16 evaluates a signal strength of the received signal. Depending on the constant signal strength of the transmitted signal, a geometric arrangement of the three secondary-sided antenna elements 10, a distance of the primary winding structure to the secondary winding structure along a vertical direction z can be determined. Further, an orientation of a longitudinal axis x of the primary winding structure relative to a longitudinal axis x of the secondary winding structure can be determined. If the distance is within a predetermined distance interval and the orientation, e.g. in form of an angle, is within a predetermined orientation interval, a correct position and orientation of the secondary winding structure relative to the primary winding structure can be determined. This information can be used in order to enable an inductive power transfer.