Apparatus for wireless power transfer system for charging a vehicle

Abstract

The invention relates to a device (20) for a wireless power transfer system (3) for charging a vehicle (1). The device comprises a coil (21) having a first sub-coil (22) and a second sub-coil (23), which are both formed from one and the same continuous electrically conductive wire (24). The first sub-coil (22) and the second sub-coil (23) are movably arranged relative to each other for adjusting charging characteristics of the device (20).

Description

TECHNICAL FIELD

[0001] The present invention relates to an apparatus for a wireless power transfer system for charging a vehicle, a transmitter / receiver and a wireless power transfer system for charging a vehicle. BACKGROUND

[0002] Electric vehicles and plug-in hybrid vehicles can be charged wirelessly by means of induction coils. Typically, a first coil of the transmitter is arranged in a base pad of a floor or ground and a second coil of the receiver is arranged in a vehicle pad on the underside of the vehicle. Standards provide that the same base pad shall be able to operate at several power levels within a power interval and at several Z-classes within a clearance-to-ground interval.

[0003] Furthermore, there are many different coil topologies used for the coils of the vehicle pad and in some cases it can be difficult to achieve an efficient charging due to a mismatch of the topologies between the transmitter of the base pad and the receiver of the vehicle pad.

[0004] Therefore, it is difficult to optimize the base pad for all possible relevant different cases to efficiently transfer power.

[0005] Furthermore, the charging requires a relatively accurate alignment between the base pad and the vehicle pad. SUMMARY

[0006] It is an object of the present invention to provide an apparatus for a wireless power transfer system for charging a vehicle which can be used to improve the efficiency of the wireless charging of the vehicle.

[0007] This object is achieved by an apparatus for a wireless power transfer system for charging a vehicle, wherein the apparatus comprises a coil having a first sub-coil and a second sub-coil, the first sub-coil and the second sub-coil are both formed by one and the same continuous electrically conductive wire, and wherein the first sub-coil and the second sub-coil are movably arranged relative to each other for adjusting charging properties of the apparatus.

[0008] The present invention is based on the insight that by means of such an apparatus, by the relative movement of the first sub-coil and the second sub-coil, the magnetic field of the transmitter can be adjusted to current conditions for matching the coil type and coil position of the receiver, so that the electromagnetic coupling between the transmitter and the receiver can be improved and the vehicle can be efficiently charged. The magnetic field can be optimized for several power levels and Z-classes and the alignment tolerance interval for positioning the base pad and the vehicle pad relative to each other will increase.

[0009] The first and second sub-coils are preferably arranged in a housing accommodating the coil. One of the first and second sub-coils can be movably arranged relative to the housing, or both of the first and second sub-coils can be movably arranged relative to the housing. In other words, one of the sub-coils can be moved, while the other sub-coil is stationary, or both sub-coils can be moved.

[0010] According to one embodiment of the device, the first and second sub-coils are movable relative to each other in a direction substantially parallel to the main extension plane of the coil. Thus, the magnetic field of the transmitter (receiver) can be suitably adjusted to match the corresponding receiver (transmitter) coil.

[0011] According to another embodiment, the main extension plane of the first sub-coil and the main extension plane of the second sub-coil coincide with the main extension plane of the coil. Thus, a relatively flat and thin substrate or vehicle-mounted board can be achieved by using, for example, a DD coil.

[0012] According to another embodiment, the main extension plane of the coil is desirably substantially horizontal when the device is installed in a charging facility for a vehicle, and preferably, the first and second sub-coils are movable relative to each other in a direction determined to be substantially horizontal when the device is installed in a charging facility for a vehicle. Thus, by moving the sub-coils relative to each other in the XY plane when charging the vehicle, magnetic field adjustment can be made for different distances in the Z-axis direction between the substrate and the vehicle-mounted board.

[0013] According to another embodiment, the first and second sub-coils are movable relative to each other in a direction determined to be substantially parallel to the direction of travel of the vehicle when such a vehicle is positioned above the device installed in a charging facility for a vehicle. Thus, a correction can be made to compensate for how incorrectly positioned the vehicle (vehicle-mounted board) is relative to the substrate in the direction of travel of the vehicle, allowing for more efficient electromagnetic coupling between the substrate and the vehicle-mounted board.

[0014] According to another embodiment, a portion of the electrically conductive wire extending between the first and second sub-coils has slack for allowing the first and second sub-coils to be moved relative to each other in a direction away from each other. Thus, the sub-coils can be moved relative to each other without introducing any tension in the electrically conductive wire.

[0015] According to another embodiment, the coil is a DD coil having two "D" sections, which constitute the first and second sub-coils, respectively. Thus, a coil having a relatively high alignment tolerance and small size that can be used to charge a vehicle can be achieved simultaneously, since adjustment of the coil magnetic field can be made.

[0016] According to another embodiment, the device has a first holding portion, wherein the first sub-coil is arranged in the first holding portion for holding the position of the first sub-coil relative to the first holding portion, and a second holding portion, wherein the second sub-coil is arranged in the second holding portion for holding the position of the second sub-coil relative to the second holding portion, and wherein the first holding portion and the second holding portion are movable relative to each other. Thus, the sub-coils can be arranged in a manner that they can be moved relative to each other in a controlled manner.

[0017] According to another embodiment, the device comprises a housing accommodating the first holding portion and the second holding portion, wherein the first holding portion is movable relative to the housing without moving the second holding portion. Thus, in addition to the housing protecting the coils, the second sub-coil can be held fixed relative to the housing, which constitutes a reference point for the position of this sub-coil.

[0018] According to another embodiment, the second holding portion is movable relative to the housing without moving the first holding portion. Thus, correspondingly, the first sub-coil can be held fixed relative to the housing, which constitutes a reference point for the position of this sub-coil.

[0019] According to another embodiment, the device has an actuator for moving the first holding portion relative to the housing, and preferably the actuator comprises a belt connected to the first holding portion, a plurality of rollers for receiving the belt, and a drive unit for driving the belt. Thereby, a reasonable way of moving the holding portion and thereby the sub-coils can be achieved.

[0020] Another aspect of the present invention relates to a transmitter / receiver, and another aspect of the present invention relates to a wireless power transfer system for charging a vehicle. The transmitter / receiver and the system have essentially the same advantages as the above-mentioned device.

[0021] Further advantages and advantageous features of the present invention are disclosed in the following description and claims. BRIEF DESCRIPTION OF DRAWINGS

[0022] With reference to the appended drawings, below follows a more detailed description of embodiments of the application cited as examples.

[0023] In the drawings:

[0024] Figure 1 is a schematic view illustrating a charging station and a vehicle,

[0025] Figure 2 is an exploded view of a device of a wireless power transfer system for charging a vehicle,

[0026] Figure 3a is Figure 2A perspective view of the device shows a first sub-coil arranged in the first holding part and a second sub-coil arranged in the second holding part.

[0027] Figure 3b yes Figure 2 A three-dimensional diagram of the device, in which... Figure 3a In comparison, the first holding part and the second holding part have moved relative to each other, and

[0028] Figure 4 It is shown that it is used relative to Figure 2 The figure shows a perspective view of the actuator of the housing moving and holding part of the device. Detailed Implementation

[0029] Figure 1 A vehicle 1 is shown positioned at a charging facility 2, such as a charging station, for use with a wireless power transmission system 3. The wireless power transmission system 3 includes a transmitter 4 disposed on a floor 5 and a receiver 6 disposed within the vehicle 1. The transmitter 4 can be disposed on the floor or ground, or in a substrate. Furthermore, the receiver 6 is preferably disposed on the underside of the vehicle 1 within a vehicle-mounted panel.

[0030] Transmitter 4 has a main coil for generating an electromagnetic field, and receiver 6 has a secondary coil for interacting with the generated electromagnetic field to achieve power transfer from the main coil to the secondary coil via electromagnetic induction. Power input 7 of transmitter 4 can be wirelessly transmitted from transmitter 4 to receiver 6 to achieve power output 8 from receiver 6. The wireless transmission of energy is schematically shown by arrow 11.

[0031] In the example shown, transmitter 4 is powered by a power source 9 electrically connected to transmitter 4. The power source and its power output port can be arranged in any suitable location, for example, the power source can be mounted on a wall. Receiver 6 can be connected to any device for storing and / or consuming the transmitted energy. In the example shown, receiver 6 is electrically connected to a battery 10 disposed on vehicle 1 for charging battery 10. Vehicle 1 is positioned such that transmitter 4 and receiver 6 are arranged relative to each other, such that energy can be transferred from transmitter 4 to receiver 6. Transmitter 4 and receiver 6 are spaced a predetermined distance apart in the vertical direction. Furthermore, when viewed in the vertical direction, transmitter 4 and receiver 6 at least partially overlap each other.

[0032] The device according to the invention is applicable to providing a transmitter and / or receiver for a wireless power transmission system. For example, such a wireless power transmission system device according to the invention can be used as a device arranged in... Figure 1 The components of the transmitter in the substrate shown.

[0033] It should be emphasized that when the device is used in a receiver or transmitter, the entire receiver or transmitter can also comprise other components, such as circuits and components. Furthermore, the present invention is not in any way limited to automotive applications. The device can be used in any vehicle or machine application, such as for example cars, buses, trucks, industrial trucks and automated guided vehicles, construction equipment and work machines, and trains.

[0034] Figure 2 is an exploded view of a device 20 for a wireless power transfer system for charging a vehicle. As above, the device 20 can be a part of a wireless power transfer system 3 for charging a vehicle. Figure 1

[0035] The device 20 comprises a coil 21 having a first sub-coil 22 and a second sub-coil 23. Both the first sub-coil 22 and the second sub-coil 23 are formed by the same continuous electrically conductive wire 24. Although other types of electrically conductive wire can be used, the electrically conductive wire 24 is preferably a sum of many small strands of copper wire, for example a so-called Litz wire, where the copper wires are individually insulated. The coil can have a Double-D (DD) winding pattern configuration, also referred to as a Double-D (DD) coil topology, where each of the first sub-coil 22 and the second sub-coil 23 constitutes a "D" part of the DD coil. Alternatively, each of the first sub-coil and the second sub-coil can have a Circular Square (CS) winding pattern configuration, also referred to as a Circular Square (CS) coil topology.

[0036] Such DD and CS coil topologies are suitable for use in transmitters and receivers for charging vehicles, but other topologies are feasible as well.

[0037] The coil 21 is arranged in a housing 25. The housing has a top cover 26 and a bottom cover 27, which are shown separately from each other in Figure 2 The top cover 26 and the bottom cover 27 are connectable to each other for housing the coil 21 inside the housing 25. The top cover 26 and the bottom cover 27 are mechanically connectable to each other to form the housing. In addition to the coil 21, one or more ferrite plates 28 are arranged inside the housing 25 between the coil 21 and the bottom cover 27. A back plate 29 is provided between the bottom cover 27 and the ferrite plates 28. The back plate 29 is an isolating plate made of, for example, aluminum. These components arranged inside the housing 25 are shown to be between the top cover 26 and the bottom cover 27.

[0038] The number of ferrite plates 28 can vary, and such ferrite plates can in turn be divided into a plurality of sub-ferrite plates and / or designed in different shapes. The function and design of such ferrite plates are well known to a person skilled in the art and are not further explained herein.

[0039] Figure 3a and 3b is Figure 2 ​a perspective view of the device 20 in which the housing 25 and other components have been assembled. For illustration purposes only, the housing 25 is drawn as transparent to show the components arranged within the housing.

[0040] As Figure 3a illustrated, the device 20 suitably comprises a first holding portion 30 in which the first sub-coil 22 is arranged for holding the position of the first sub-coil 22 relative to the first holding portion, and a second holding portion 31 in which the second sub-coil 23 is arranged for holding the position of the second sub-coil 23 relative to the second holding portion. Each holding portion 30, 31 is adapted to be plate-like with a relatively small thickness, and has a main extension plane extending in parallel with the main extension plane of the housing 25. Each holding portion 30, 31 can have a groove, a recess or a protruding wall 32 for receiving and holding the sub-coil 22, 23 in a predetermined winding pattern. See also Figure 2 .

[0041] The first sub-coil 22 and the second sub-coil 23 are movably arranged relative to each other for adjusting the charging properties of the device 20. This can be achieved by enabling the first sub-coil 22 and / or the second sub-coil 23 to move relative to the housing 25.

[0042] In the example embodiment illustrated in Figure 3a , 3b the first holding portion 30 and the second holding portion 31 are movable relative to each other, and thereby the sub-coils 22, 23 are movable relative to each other. The first holding portion 30 is movable relative to the housing 25 without moving the second holding portion 31, and vice versa. Although in the illustrated example embodiment both the first holding portion 30 and the second holding portion 31 are movable independently relative to the housing 25, in another embodiment one holding portion is movable and the other holding portion can be fixed relative to the housing.

[0043] The portion 33 of the electrically conductive wire 24 extending between the first sub-coil 22 and the second sub-coil 23 can have a slack for allowing the first sub-coil 22 and the second sub-coil 23 to move relative to each other in a direction away from each other. In Figure 3a , the electrically conductive wire portion 33 has a maximum slack as the first holding portion 30 and the second holding portion 31 are brought as close to each other as possible. The electrically conductive wire portion 33 forms one or more S-shapes. This enables the holding portions to be moved away from each other as illustrated in Figure 3b , where the slack of the electrically conductive wire portion 33 is used to compensate for the increasing distance between the first holding portion 30 and the second holding portion 31.

[0044] In Figure 3a and 3bA Cartesian coordinate system with axes X, Y and Z is shown in the middle. The first sub-coil 22 and the second sub-coil 23 are movable relative to each other in a direction 34 which is substantially parallel to the main extension plane 35 of the coil 21. The main extension plane 35 of the coil 21 is parallel to the XY plane. In addition to this main extension, the coil 21 has a relatively small thickness in a direction parallel to the Z axis. The main extension plane of the first sub-coil 22 and the main extension plane of the second sub-coil 23 are preferably coincident with the main extension plane 35 of the coil 21.

[0045] The direction 34 of movement of the first sub-coil 22 and the second sub-coil 23 is indicated with an arrow parallel to the X axis. Figure 1 A Cartesian coordinate system with axes X, Y and Z and a direction 34 of movement are also shown in the middle. In operation, after installation, the first sub-coil 22 and the second sub-coil 23 are preferably movable relative to each other in the direction 34, which is expected and designed to be substantially horizontal when the device 20 is installed in the charging station 2. Thus, in this case, the device 20 is arranged such that the Z axis is parallel to the vertical direction and the XY plane is horizontal. In other words, as shown in the middle, the main extension plane 35 of the coil 21 is expected and designed to be substantially horizontal when the device 20 is installed in the charging station 2. Figure 1

[0046] The vehicle to be charged at the charging station 2 is suitably guided in a predetermined direction to align with the base plate comprising the transmitter 4. Thus, when approaching the charging position, the vehicle will have a predetermined driving direction 36. When this vehicle 1 is positioned above the device 20 installed in the charging station 2, the first sub-coil 22 and the second sub-coil 23 are suitably movable relative to each other in a direction 34 which is expected and designed to be substantially parallel to the driving direction 36 of the vehicle 1.

[0047] Figure 4 An enlarged portion of the device 20 is shown in perspective view. The device 20 comprises an actuator 40 for moving the first holding part 30 relative to the second holding part 31.

[0048] The first holding part 30 is movable relative to the housing 25 without moving the second holding part 31. The actuator 40 has a belt 41 connected to the first holding part 30, a plurality of rollers 42a, 42b for receiving the belt 41, and a drive unit 43 for driving the belt. The first holding part 30 and the belt 41 can be permanently connected to each other or only when the first holding part 30 is to be moved.

[0049] For example, the rollers 42a, 42b can be pulleys or pulleys. In Figure 4 ​In the illustrated example embodiment, a first roller 42a is arranged at a back plate 29 at a first end 44 of the device 20. The first roller 42a may be arranged on a shaft of a drive unit 43, which in turn is arranged on the back plate 29. The back plate 29 is suitably fixed relative to the housing 25 such that a first retainer 30 can move relative to the housing 25. A second roller 42b may be arranged on a shaft that is arranged on the back plate 29 at the opposite second end 45 of the device 20. A belt 41 is driven by the drive unit 43 and runs over the rollers 42a and 42b and passes through a second retainer 31. The second retainer 31 has a through hole 46 that allows the belt 41 to pass through without carrying the second retainer 31.

[0050] The drive unit 43 can be an electric motor, such as a stepper motor used to drive the belt 41.

[0051] like Figure 2 , 3a As shown in 3b, the device 20 may have an additional actuator for moving the second retainer 31 relative to the first retainer 30. In this case, the second retainer 31 can move relative to the housing 25 without moving the first retainer 30. This actuator may be similar to the actuator already described for the first retainer and is arranged on the opposite side of the back plate relative to the actuator for the first retainer. Except that the belt is connected to the second retainer 31 and the first retainer 30 has a through hole that allows the belt to pass through without carrying the first retainer, the functions and components may be the same.

[0052] It should be understood that the present invention is not limited to the embodiments described above and shown in the accompanying drawings; rather, those skilled in the art will recognize that many changes and modifications can be made within the scope of the appended claims.

Claims

1. A device (20) for a wireless power transmission system (3) for charging a vehicle (1), the device comprising a coil (21) having a first sub-coil (22) and a second sub-coil (23), both the first sub-coil (22) and the second sub-coil (23) being formed from the same continuous conductive wire (24), characterized in that, The first sub-coil (22) and the second sub-coil (23) are movably arranged relative to each other for adjusting the charging characteristics of the device (20).

2. The apparatus according to claim 1, characterized in that, The first sub-coil (22) and the second sub-coil (23) are capable of moving relative to each other in a direction (34) substantially parallel to the main extension plane (35) of the coil (21).

3. The apparatus according to claim 2, characterized in that, The main extension plane of the first sub-coil (22) and the main extension plane of the second sub-coil (23) coincide with the main extension plane (35) of the coil (21).

4. The apparatus according to claim 2, characterized in that, When the device (20) is installed in the charging facility (2) for the vehicle (1), the main extension plane (35) of the coil (21) is determined to be basically horizontal.

5. The apparatus according to claim 3, characterized in that, When the device (20) is installed in the charging facility (2) for the vehicle (1), the main extension plane (35) of the coil (21) is determined to be basically horizontal.

6. The apparatus according to any one of claims 1 to 5, characterized in that, When such a vehicle is located above the device (20) installed in the charging facility (2) for the vehicle (1), the first sub-coil (22) and the second sub-coil (23) are able to move relative to each other in a direction (34) determined to be substantially parallel to the driving direction (36) of the vehicle (1).

7. The apparatus according to any one of claims 1 to 5, characterized in that, The portion (33) of the conductive wire (24) extending between the first sub-coil (22) and the second sub-coil (23) has slack to allow the first sub-coil (22) and the second sub-coil (23) to move relative to each other in a direction away from each other (34).

8. The apparatus according to any one of claims 1 to 5, characterized in that, The coil (21) is a DD coil with two "D" parts, which respectively constitute the first sub-coil (22) and the second sub-coil (23).

9. The apparatus according to any one of claims 1 to 5, characterized in that, The device (20) has: A first holding part (30) is provided, in which the first sub-coil (22) is arranged to maintain the position of the first sub-coil (22) relative to the first holding part (30); as well as The second holding part (31) is provided, and the second sub-coil (23) is arranged in the second holding part (31) to maintain the position of the second sub-coil (23) relative to the second holding part (31). The first holding part (30) and the second holding part (31) are movable relative to each other.

10. The apparatus according to claim 9, characterized in that, The device (20) includes a housing (25) that houses the first holding part (30) and the second holding part (31), wherein the first holding part (30) is movable relative to the housing (25) without moving the second holding part (31).

11. The apparatus according to claim 10, characterized in that, Without moving the first retaining part (30), the second retaining part (31) can move relative to the housing (25).

12. The apparatus according to claim 10, characterized in that, The device (20) includes an actuator (40) for moving the first holding part (30) relative to the housing (25).

13. The apparatus according to claim 11, characterized in that, The device (20) includes an actuator (40) for moving the first holding part (30) relative to the housing (25).

14. The apparatus according to claim 12, characterized in that, The actuator (40) has a belt (41) connected to the first retaining part (30), a plurality of rollers (40a, 40b) for receiving the belt (41), and a drive unit (43) for driving the belt (41).

15. The apparatus according to claim 13, characterized in that, The actuator (40) has a belt (41) connected to the first retaining part (30), a plurality of rollers (40a, 40b) for receiving the belt (41), and a drive unit (43) for driving the belt (41).

16. A transmitter (4) or receiver for a wireless power transmission system (3) for charging a vehicle (1), wherein, The transmitter / receiver includes the apparatus (20) according to any one of claims 1 to 15.

17. A wireless power transmission system (3) for charging a vehicle (1), the system comprising a substrate for interacting with an onboard panel disposed on the vehicle (1), the substrate comprising a device (20) according to any one of claims 1 to 15.

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