Secondary coil topology

Abstract

To provide a secondary coil topology.SOLUTION: The present invention relates to a coil device for an induction type reception system, and comprises: a first coil 1 having a plurality of first wirings; and a second coil 2 having a plurality of second wirings. The first coil and the second coil in such the case, are serially connected to each other, and are extended in mutually opposite directions. Each wiring includes: a conductor / conductive part arranged inside; and a conductor / conductive part arranged outside. In order to improve a relative operation property of the coil device, the conductors that are at least part of the first and second wirings, and arranged inside and outside, are each positioned in one flat surface, or arranged so as to be crossed over the one flat surface. Those flat surfaces are branched in a direction from the first coil to the second coil or an opposite direction in accordance with whether the conductive part is the first wiring or the second wiring.SELECTED DRAWING: Figure 2b

Description

Technical Field

[0001] The present invention relates to a coil device for receiving an alternating magnetic field, in particular for an inductive charging system. This coil device is also provided for a secondary device of an inductive charging system for inductively transmitting energy to a means of transport in a non-contact manner.

Background Art

[0002] Vehicles powered by their own engines, such as automobiles, motorcycles, and locomotives, are understood in the following by the term "means of transport". Such vehicles may or may not be connected to a railway. The engine may include an internal combustion engine, an electric motor, or a combination of these two, for example in the form of a hybrid drive.

[0003] The term "inductive charging system" is understood as a system for non-contact energy transmission by means of an alternating magnetic field. This system includes a primary device (also referred to as "primary system" or "primary element") as an energy source and a secondary device (also referred to as "secondary system" or "secondary element") as an energy receiver similar to a transformer device. The primary device is designed to generate an alternating magnetic field. The secondary device is designed to receive the alternating magnetic field and to generate an induced current from the alternating magnetic field. The generation of the alternating magnetic field is achieved by an alternating current flowing through a conductor of the primary device, in particular a coil, and the generation of the induced current is achieved by a conductor of the secondary device arranged in the magnetic field.

[0004] Patent Document 1 describes an apparatus for wirelessly transmitting power, including a first coil having a first winding path and a second coil having a second winding path. This apparatus includes a holding device configured to hold the first coil and the second coil in a predetermined winding pattern. The first winding path and the second winding path each include a plurality of consecutive winding groups. In each of the plurality of consecutive winding groups, at least a part of the consecutive windings is disposed on top of the immediately preceding winding on the holding device for a predetermined number of windings. The disclosed coil configuration can function as either a transmitter or a receiver.

[0005] Basically, two different coil topologies are used for electromagnetic induction. The first coil topology is a circular coil, i.e., a coil that rotates at least once around a center. The second coil topology is a bipolar coil (also known as a double D coil) including a first coil having one or more turns around a first center and a second coil having one or more turns around a second center. The first coil is electrically connected to the second coil in series and is wound in the opposite direction to the second coil.

[0006] The prior art shows the drawback that the coil arrangement is designed only for a specific magnetic field pattern that functions optimally and enables optimal energy transfer. Technically, such coil arrangements have interoperability problems. This means, for example, that a vehicle having a secondary coil of one manufacturer cannot be charged without high losses (interoperability) on a fixed device having a primary coil of another manufacturer.

[0007] Therefore, for each generated magnetic field pattern, a specific secondary coil topology is preferred to achieve optimal energy transfer from at least one primary coil to at least one secondary coil.

[0008] In order to improve the interoperability of the secondary coil, currently, additional receiving coils, each more suitable for receiving the corresponding magnetic field pattern, are added. However, such coil arrangements have the disadvantages of high weight and high cost.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0010] Accordingly, an object of the present invention is to provide an improved coil device for an inductive receiving system, that is, a secondary coil having higher interoperability, which is cost-effective and has a simple structure at the same time.

Means for Solving the Problems

[0011] For this purpose, the present invention provides a coil device according to claim 1. This coil device is particularly configured to include a first coil having a first winding path A or a plurality of first windings, and a second coil having a second winding path B or a plurality of second windings. The first coil and the second coil are connected in series with each other and are formed in opposite directions with respect to each other. This means, in particular, that the two winding paths are configured such that the current flowing through the two coils is clockwise in the first winding path and counterclockwise in the second winding path, or vice versa. Each winding has a conductor / conductor portion arranged on the inside and a conductor / conductor portion arranged on the outside, and these are particularly arranged parallel to each other. In the coil device according to the present invention, at least a part of the conductors arranged on the inside and the conductors arranged on the outside of the first winding and the second winding are arranged such that they are located in one plane or span across one plane. Depending on whether the conductor / conductor portion is that of the first winding or that of the second winding, these planes branch from each other from the first coil to the second coil or in the reverse direction.

[0012] In this regard, it has been found that the coil device according to the present invention has a higher interoperability with different magnetic field patterns of both circular coils and bipolar coils. As a result, the coil device is made more flexible with respect to its application range and can thus be used with a number of different primary coils.

[0013] Another advantage is that the coil device has an improved, i.e., increased, Alignment Offset. This means that it is not necessary to place the coil device centrally or at a specific point with respect to the primary coil in order to always achieve the highest transmission efficiency. In other words, when the coil device is offset from a predetermined point with respect to the primary coil, it shows a smaller decrease in transmission efficiency compared to the prior art, and the transmission efficiency remains almost constant. Therefore, the alignment of the coil device becomes easier, and a constant energy transfer is more resistant to misalignment between the secondary coil and the primary coil.

[0014] In a preferred embodiment, the coil device further includes a ferrite arrangement configured to at least partially cover a winding path section disposed in the center of the coil device, i.e., on one side, particularly on the side of the inductive transmitter system or the primary coil, and a conductor disposed inside the first coil and the second coil, and does not at least partially cover, or does not cover at all, the remaining winding path sections of the first coil and the second coil on this side. The ferrite arrangement promotes better magnetic field induction and, therefore, more effective energy transfer. This is particularly generated by at least partially covering the centrally disposed winding path section, which is achieved by at least one ferrite arrangement disposed on the intermediate conductor, and therefore mimics a solenoid coil.

[0015] There are also embodiments in which the centrally disposed conductor is completely covered by one or more ferrite arrangements, but preferably at least 50% of the winding path section is covered. The ferrite arrangement can also extend to the conductors of the first and second coils that are opposed and disposed externally, and therefore can, in particular, at least partially cover the same.

[0016] Furthermore, the remaining winding path sections, i.e., all conductor portions except the conductors arranged in the center or internally, especially the side covered by the internally arranged winding path sections, are not covered at all by the ferrite arrangement.

[0017] The ferrite arrangement similarly has the advantage of being used as a holding device for the coil. Thus, the ferrite arrangement performs a plurality of functions, such as, for example, magnetic field induction, especially stray magnetic field reduction and positioning and holding of the coil conductors.

[0018] In a preferred embodiment, the first coil and the second coil are each formed spirally, especially on at least one surface. In this case, the diameter of the winding increases from one winding of each coil to the subsequent winding. This has the advantage of managing or reducing the height of the coil device and especially forming it flat. In this case, the winding can describe a circular, square, rectangular or any other arbitrary geometric shape.

[0019] To create a particularly homogeneous shape of the coil device, the conductors / conductor portions arranged internally are arranged adjacent to each other and especially at least partially parallel to each other. This shape is made homogeneous and is efficient in space utilization. Furthermore, for example, the interoperability with circular coils is improved.

[0020] Preferably, the distance between the conductors / conductor portions arranged internally directly adjacent to the first coil and the second coil is greater than the distance between the conductors / conductor portions arranged externally directly adjacent to the first coil and the second coil. This has the advantage that the characteristics of the bipolar coil are not dominant, and thus the coil device is not oriented only to this shape and the corresponding magnetic field.

[0021] Furthermore, it has been clarified that it is effective when conductors arranged on the directly adjacent side portions of the first coil and the second coil are arranged in pairs and at least partially overlap each other. This can reduce the width of the corresponding path section, and thus can reduce the dimensions or extension in the width and length of the coil device. In particular, based on the ferrite arrangement according to the present invention, arranging the conductors overlapping each other or stacking them on top of each other within the corresponding path section is advantageous because the space utilization regarding the height of the coil device is determined by the ferrite arrangement. Also, in particular, depending on the height of the ferrite arrangement and the diameter of the conductors, it is also possible to arrange three or more conductors overlapping each other.

[0022] Preferably, the ferrite arrangement includes two rectangular ferrite plate assemblies (or ferrite moldings, or ferrite devices) arranged parallel to and spaced apart from each other, and two supply conductors for the two coils may extend between the ferrite plate assemblies. This has the advantage of reducing weight and at the same time providing space for the supply conductors. Since the two ferrite plate assemblies can be formed identically to each other and arranged symmetrically with respect to the coil device, the corresponding magnetic field is not adversely affected.

[0023] Furthermore, it has been clarified that it is advantageous when the ferrite plate assembly is formed from a plurality of identically formed or configured ferrite plates and / or molded parts having a predetermined magnetic permeability. In addition to known ferrite plates, molded parts may be used. Instead of or in addition to the ferrite plate assembly, it is also possible to use ferrite concrete as the ferrite arrangement. The ferrite concrete can be stirred fluidly like concrete and poured into a predetermined mold before hardening. This concrete has a lower magnetic permeability but can be dimensioned geometrically or structurally to match the characteristics of the ferrite plate assembly.

[0024] Preferably, each ferrite plate assembly has a recess in which a conductor / conductor portion arranged inside the first coil and the second coil is disposed. This has the advantage of reducing the height of the coil device and shrinking the required space. In a further advantageous embodiment, the ferrite arrangement extends beyond the conductor / conductor portion arranged outside the first coil and the second coil. This additional extension of the ferrite arrangement serves to stabilize the device and also helps to reduce the stray magnetic field, i.e., to focus the magnetic field on one or more coils.

[0025] To further improve the magnetic field shape or the progression of the magnetic field, the conductor / conductor portion arranged inside is disposed on a first plane, and the conductor / conductor portion arranged outside is disposed on a second plane, and the first plane is arranged parallel and spaced apart from the second plane.

[0026] The coil device according to the present invention can be incorporated into either a secondary system or a primary system. That is, this coil device may be used as a receiving device or as a transmitting device or a transceiver (for example, a transceiver).

[0027] The figures described below relate to preferred embodiments of the present invention and are not limiting, but rather are used to additionally explain and clarify the features of the illustrated coil device. These features can be combined with the above-described embodiments individually or in combination. Features denoted by the same reference numerals in different drawings may be the same.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2a

Figure 2b

Figure 2c

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0029] Figure 1 shows a coil device as a preferred embodiment according to the present invention having a first coil 1 and a second coil 2 in a plan view. Coils 1 and 2 are provided with a common electrical conductor and are therefore electrically connected in series. Coils 1 and 2 are in a spiral shape, arranged side by side, and are electrically contactable or connectable via two current supply conductors or current connection portions 9a and 9b. Except for some minor details, the two coils 1 and 2 are arranged and shaped to be axially symmetric with respect to each other. Each coil 1 and 2 has its own winding path A and B respectively, and this winding path forms a part of the common electrical conductor respectively and is divided into four path sections or conductor portions respectively. The first coil 1 is divided into regions of a first path section A1, a second path section A2, a third path section A3, and a fourth path section A4, and these path sections A1 to A4 are arranged continuously counterclockwise. The second coil 2 is divided into regions of a first path section B1, a second path section B2, a third path section B3, and a fourth path section B4, and these path sections B1 to B4 are arranged continuously clockwise. Therefore, the following path sections are arranged opposite to each other inside the coil: path sections A2 and A4 (also referred to as conductors / conductor portions arranged on the side of the first coil), path sections A1 and A3 (also referred to as conductors / conductor portions arranged inside and outside the first coil), path sections B2 and B4 (also referred to as conductors / conductor portions arranged on the side of the second coil), and path sections B1 and B3 (also referred to as conductors / conductor portions arranged inside and outside the second coil). Further, path sections A1 and B1 of the first coil and the second coil 1 and 2 are directly adjacent to each other. In the present invention, a path section defines a region of a coil, and within that region, the conductor / conductor portion arranged within that region has predetermined characteristics regarding its arrangement and shaping. The difference with respect to this defined portion exists within the transition boundary between different winding path sections where the conductor draws a bent portion or a curve and leads into the next winding path section.

[0030] All winding path sections A1 to A4 and B1 to B4 are characterized in that the conductors arranged therein are arranged such that they are essentially straight and parallel to each other. Winding path sections A1 and B1 are exceptions in that the conductors in these sections have a kind of step or bend in their respective centers. The function of the step is to start a new winding or circuit of the first coil or the second coil, increase the diameter of the winding towards the center of the coil device, and thereby allow the remaining portions of the common conductor to be shaped straight and parallel, especially within sections A1 and B1. The spacing between two adjacent conductors is always of equal magnitude within path sections A1 and B1 and is, in particular, greater than the spacing between the conductors in path sections A3 and B3. The greater spacing between the conductors within path sections A1 and B1 weakens the characteristics of the bipolar coil topology. The particularity in sections A3 and B3 lies in the arrangement of the conductors: for example, within sections B1, B2, and B4, the conductors are along the outer ends of the coil, whereas the same conductors are arranged at the inner ends of the coil or at the coil opening within section B3. The opposite is true for the inner conductors within sections B1, B2, and B4, which are arranged at the outer ends of the coil or the coil device within section B3. Within path sections A2, A4, B2, and B4, the conductors are arranged in pairs and stacked on top of each other as the width of the coil device decreases. The coil device further has a ferrite arrangement 3 consisting of two equally formed ferrite plate assemblies 3a and 3b. Here, it should be noted that in other embodiments, it is possible to use more than two and / or ferrite plate assemblies formed in different shapes and / or sizes. Ferrite plate assemblies 3a and 3b each pass through two coils 1 and 2 and extend completely over the entire length of the coil device, i.e., from the left end of the first coil 1 to the right end of the second coil 2. Depending on the height of the ferrite arrangement, it is of course also possible to stack two or more conductors on top of each other in order to make the coil device more compact.On one side of the coil device, current supply conductors 9a and 9b are seen extending toward the center of the coil device between the ferrite plate assemblies 3a and 3b, and ultimately forming the coils 1 and 2 by being spirally formed in the clockwise and counterclockwise directions respectively, that is, by being wound multiple times.

[0031] Figure 2A shows in plan view the two ferrite plate assemblies 3a and 3b of FIG. 1, which are each formed from a plurality of ferrite plates 4 formed identically. Each ferrite plate 4 has a length of 90 mm, a width of 30 mm, and a height of 9 mm. Each ferrite plate assembly 3a and 3b has a length of 380 mm and a width of 90 mm, and is arranged parallel to each other so as to be able to cover a width of 210 mm. That is, the ferrite plate assemblies 3a and 3b are spaced 30 mm apart from each other. The ferrite plates 4 are arranged parallel and flush with each other with no gaps therebetween.

[0032] Figure 2B shows a longitudinal sectional view of the ferrite plate assemblies 3a and 3b described in Figure 2A above, and also shows the conductors of coils 1 and 2. Here, conductors consisting of winding path sections A1, A3, B1, and B3 are also drawn, that is, the conductors / conductor portions arranged inside and outside the first coil and the second coil are shown. The ferrite arrangement includes a ferrite plate 4a in the first upper plane and a ferrite plate 4b in the second lower plane. The conductors in path sections A3 and B3 are arranged directly continuously, while the conductors in path sections A1 and B1 are arranged at equal intervals from each other. The conductors in path sections A1 and B1 are arranged on the first upper plane, and the conductors in path sections A3 and B3 are arranged on the second lower plane. The total length of the ferrite plate 4b arranged on the lower side is set to 180 mm based on the lengths of the two ferrite plates. The two ferrite plate arrangements consisting of the ferrite plate 4a in the first plane each have a length of 120 mm, and in this case, the interval between the two arrangements on the first plane is set to 140 mm.

[0033] Figure 2C shows essentially different types of ferrite plates in terms of height and weight. All ferrite plates have a length of 90 mm and a width of 30 mm. The 28 ferrite plates with a height of 9 mm used for the two ferrite arrangements 3a and 3b in the coil device of Figure 1 have an overall weight of 3.3 kg. It should be noted that ferrite plates formed in different shapes and / or sizes may be used for the embodiments disclosed herein.

[0034] FIG. 3 shows a longitudinal sectional view of a coil device according to a further preferred embodiment, which has additional features as compared with the coil device of FIG. 1 or FIG. 2B. The overall height of the coil device is 23 mm. A 3 mm thick GRP cover plate 8 with a length of 420 mm and a width of 300 mm is arranged above the coil device. On its lower side, FRP frame profiles 7 with a height and width of 18 mm respectively are arranged on the right and left at the ends of the coil device. Between these, a coil and a ferrite arrangement having ferrite plates 4a, 4b already described in FIGS. 1 and 2B are arranged. On the lower side of the coil device, an aluminum plate 6 with a thickness of 2 mm and the same width and length as the GRP cover plate 8 is arranged.

[0035] As described in FIG. 2B, conductors consisting of winding path sections A1 and B1 are shown in the first plane of the coil device. A glass fiber fabric layer 10 with a thickness of 1 mm to 2 mm is arranged between these conductors and the lower ferrite plate 4b. In the second plane, conductors of winding path sections A3 and B3 are arranged and are spaced apart from the ferrite plate 4a and the aluminum plate 6 by the glass fiber fabric layer 10. A plastic layer 5 with a thickness of 9 mm is arranged between the conductors of winding path sections A3 and B3 and the ferrite plate 4b, which functions as a spacer and a structural support member. The plastic layer 5 has a width of 55 mm and a height of 9 mm. The widths of winding path sections A3 and B3 are 45 mm respectively.

[0036] Figure 4 shows three different cross-sectional views along the width of the coil device of FIG. 3. The upper drawing in FIG. 4 shows a cross-section passing through the center of the coil device and through the boundary line between the winding path sections A1 and B1 described above. In particular, the conductor consisting of the supply conductor 9b and the winding path section A1 or B1 on the lower plane is shown. The central drawing in FIG. 4 shows a cross-section at about one-fourth of the length of the coil device. In the center, the two supply conductors 9a and 9b, and the conductors arranged in pairs and overlapped within the path sections A2 and A4 are recognized. A plastic layer 5 is also shown below the ferrite plate 4a. The lowermost drawing in FIG. 4 shows a cross-sectional view of the outermost part of the coil device. The cross-section extends through the path section A3, and the conductor A consisting of the path section A3 is shown. Further, the supply conductors 9a and 9b are arranged.

Explanation of Signs

[0037] 1 First coil 2 Second coil 3 Ferrite arrangement 3a First ferrite plate assembly 3b Second ferrite plate assembly 4 Ferrite plate 4a Ferrite plate in the first upper plane 4b Ferrite plate in the second lower plane 5 Plastic layer 6 Aluminum plate 7 FRP (Fiber Reinforced Plastic) frame profile 8 GRP (Glass Fiber Reinforced Plastic) cover plate 9a Supply conductor 9b Supply conductor 10 Glass fiber fabric layer A1 First path section of the first coil or conductor / conductor part arranged inside A2 Second path section of the first coil or conductor / conductor part arranged laterally Conductor / conductor portion arranged in the third pass section or outside of the first coil Conductor / conductor portion arranged in the fourth pass section or laterally of the first coil Conductor / conductor portion arranged in the first pass section or inside of the second coil Conductor / conductor portion arranged in the second pass section or laterally of the second coil Conductor / conductor portion arranged in the third pass section or outside of the second coil Conductor / conductor portion arranged in the fourth pass section or laterally of the second coil First winding path of the first coil Second winding path of the second coil

Claims

1. 1. A coil arrangement for an inductive receiving system, comprising: A first coil (1) having a plurality of first windings; A second coil (2) having a plurality of second windings, The first coil and the second coil (1;2) are connected in series with each other and configured to extend in opposite directions relative to each other, each winding having an inner conductor / conductor portion and an outer conductor / conductor portion; A coil device, characterized in that the inner and outer conductors of at least a portion of the first winding and the second winding are each located within a single plane or arranged to span the plane, and the plane diverges from each other in a direction from the first coil to the second coil or in the opposite direction depending on whether the conductor is a conductor / conductor portion of the first winding or a conductor / conductor portion of the second winding.

2. 2. The coil arrangement according to claim 1, characterized in that the ferrite arrangement (3) is configured to at least partially cover the conductors / conductor portions arranged inside the first coil and the second coil (1; 2) on one side, in particular on the side of an inductive transmitter system, and to at least partially not cover the remaining conductors / conductor portions (A2, A3, A4, B2, B3, B4) of the first coil and the second coil (1; 2) on said side.

3. 3. The coil arrangement according to claim 1 or 2, characterized in that the first coil and the second coil (1; 2) are each formed in a helical shape.

4. 4. The coil arrangement according to claim 1, wherein the inner arranged conductors / conductor portions are arranged adjacent to one another, in particular at least partially parallel to one another.

5. 5. The coil device according to claim 1, wherein the spacing between the conductors / conductor portions of the first coil and the conductors / conductor portions of the second coil, which are immediately adjacent to each other and arranged on the inside, is greater than the spacing between the conductors / conductor portions of the first coil and the conductors / conductor portions of the second coil, which are immediately adjacent to each other and arranged on the outside.

6. 6. A coil arrangement according to claim 1, wherein directly adjacent laterally arranged conductors are arranged in pairs at least partially overlapping each other.

7. 7. The coil arrangement according to claim 1, characterized in that the ferrite arrangement (3) comprises two rectangular ferrite plate assemblies (3a; 3b) arranged parallel to and spaced apart from each other, between which run two supply conductors (9a; 9b) for the two coils (1; 2).

8. 8. The coil arrangement according to claim 7, characterized in that the ferrite plate assembly (3a, 3b) is formed from a plurality of identically molded ferrite plates (4) and / or molded parts having a predetermined magnetic permeability.

9. 9. The coil arrangement according to claim 7 or 8, characterized in that the ferrite plate assemblies (3a, 3b) have recesses therein in which conductors / conductor portions arranged inside the first coil and the second coil, respectively, are arranged.

10. 10. The coil arrangement according to claim 1, wherein the inner conductors / conductor portions are arranged on a first plane and the outer conductors / conductor portions are arranged on a second plane, the first plane being arranged parallel to and spaced apart from the second plane.

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