Main coil assembly

Abstract

The invention relates to a main coil assembly (1) for a ground module (GPM) or a vehicle module (CPM) of an inductive charging system for a vehicle. The main coil assembly (1) has a main coil (2) and magnetic flux guiding elements (4). The magnetic flux guiding elements (4) are tile-shaped, are held by a carrier element (5), and are arranged in one or more common planes.

Description

[0001] MAIN COIL ASSEMBLY

[0002] The present invention relates to a main coil assembly for a power conversion arrangement, in particular for supplying energy to an electric vehicle. A power conversion arrangement can be provided for converting the electrical power of an electrical supply current into electromagnetic power of an oscillating electromagnetic field, or vice versa. A power conversion arrangement comprises a magnetic assembly for receiving a current and for radiating an oscillating electromagnetic field, or vice versa, and an electronic assembly for receiving the electrical supply current and converting it into an alternating electrical current for supplying the magnetic assembly, or vice versa.

[0003] The power conversion assembly further comprises heat dissipation means for dissipating heat generated by the electronic assembly and / or the magnetic assembly during their respective power conversion operation.

[0004] Electric vehicle batteries can be charged with alternating current (AC) or direct current (DC). Typical AC chargers can provide a charging power of up to 22 kW. AC charging systems can be divided into wired charging systems and wireless charging systems, with wireless charging systems primarily implemented as inductive charging systems (ICS). An ICS typically consists of two separate modules, often referred to as a ground pad module (GPM) and a car pad module (CPM). The GPM is installed outside the electric vehicle, while the CPM is mounted inside the electric vehicle, usually on the underside of the vehicle. The CPM can receive the oscillating electromagnetic, predominantly magnetic, field from the GPM, convert it into an alternating current, further convert it (typically rectify it), and then generate a charging current (typically DC) used to charge a vehicle's traction battery.Wireless charging systems are often more convenient for the user, as no manual intervention is usually required to start charging the battery other than parking the vehicle over the GPM.

[0005] A power conversion assembly can be part of a GPM, for receiving an electric current and emitting an oscillating electromagnetic field. Similarly, a power conversion assembly can be part of a CPM, which receives the oscillating electromagnetic field from the GPM and converts it into a current. In principle, in both cases, the GPM or CPM can be capable of regenerative energy flow, i.e., also for energy flow in the opposite direction, i.e., from the vehicle to the charging device.

[0006] A GPM typically comprises a magnetic assembly and an electronic assembly. The magnetic assembly, also referred to as the main coil assembly, comprises a coil and ferrite elements that heat up and must be cooled during operation of the GPM. The electronic assembly also requires cooling. The magnetic and electrical assemblies can be arranged in a common housing or in separate, functionally coupled modules. Air cooling may be provided to cool the electronic assembly and / or the magnetic assembly.

[0007] A possible object of the invention is to provide a main coil assembly that has advantageous properties with regard to mechanical strength. Another possible object of the invention is to provide a main coil assembly that can be manufactured cost-effectively.

[0008] At least one of these objects is achieved by a main coil assembly having the features of patent claim 1.

[0009] The main coil assembly is intended for a ground module (GPM) or a vehicle module (CPM) of an inductive charging system for a vehicle. The main coil assembly comprises a main coil and magnetic flux guide elements. The magnetic flux guide elements are tile-shaped, held by a support element, and arranged in one or more common planes.

[0010] This makes it possible to design a comparatively large area, such as that which must be covered by the magnetic flux guide elements along the main coil, together with the carrier element from which they are formed, as a structural unit

[0011] In embodiment, the support element also carries and holds the main coil, and the main coil runs in a plane parallel to the one or more planes of the magnetic flux guide elements,

[0012] The support element can be formed in one piece, for example, as a plastic injection-molded part. In some embodiments, it is constructed in multiple pieces, with individual parts of the support element being detachably or permanently connected to one another.

[0013] The support element, which can also be called a support plate, has a flat basic shape. The magnetic flux guide elements have a flat basic shape. A flat basic shape is understood to be a shape that extends essentially parallel to a plane, with its extension in directions parallel to this plane being many times greater than its extension in the direction normal to this plane, for example, at least five or ten times greater. The envelope volume around such a shape is usually bounded at least approximately by two parallel planes.

[0014] The magnetic flux guide elements are typically made of a ferrite material. They can be shaped with a flat top and bottom surface parallel to the plane of the magnetic flux guide element. The top and / or bottom surface can also be essentially flat, for example, over at least 70%, 80%, or 90% of their surface area, and thickened or curved in the remaining areas.

[0015] In embodiments, the magnetic flux guide elements have a size between 10 cm by 10 cm and 40 cm by 40 cm, in particular between 20 cm by 20 cm and 30 cm by 30 cm.

[0016] In some embodiments, the carrier element has positioning elements, against which the magnetic flux guide elements can be pushed up to a stop during assembly of the magnetic flux guide elements on the carrier element. This enables simple assembly of the magnetic flux guide elements on the carrier element by, in a first step, placing the magnetic flux guide element on a contact surface of the carrier element and, in a second step, sliding the magnetic flux guide element parallel to the contact surface against the stop.

[0017] In some embodiments, the positioning elements define a stop in two mutually orthogonal directions in the common plane. This further simplifies assembly and allows the position of a magnetic flux guide element in the plane of the contact surface to be clearly specified. In some embodiments, the support element has spacing elements that space magnetic flux guide elements mounted on the support element apart from one another. This prevents the magnetic flux guide elements from only touching each other at specific points due to manufacturing inaccuracies in the linearity of the end faces of the magnetic flux guide elements that face each other. This, in turn, would lead to magnetic flux peaks at such contact points and to overheating at these locations.

[0018] In embodiments, the distance defined by the spacing elements is between 10% and 200% of the thickness of the magnetic flux guide elements, in particular between 50% and 150% of the thickness. This represents a good compromise between the need to avoid obstructing the magnetic flux and the mechanical manufacturability of the entire arrangement. For example, manufacturing tolerances regarding the end faces of the magnetic flux guide elements can be selected to be higher.

[0019] In embodiments, the distance is between zero and ten millimeters, in particular between half a millimeter and five millimeters.

[0020] In some embodiments, the magnetic flux guide elements are arranged on the support element in an individually replaceable manner. This allows for easy repair, particularly given that the magnetic flux guide elements are typically made of ferrite material, which is comparatively less resistant to breakage. The magnetic flux guide elements can be detachably attached to the support element, in particular, detachable without the use of tools.

[0021] In embodiments, the main coil assembly comprises tile retaining elements with which the magnetic flux guide elements are resiliently attached to the support element, in particular wherein the tile retaining elements are elastic elements. This allows for the reduction or elimination of mechanical stresses on the magnetic flux guide elements that would result from deformation of the support element.

[0022] In some embodiments, the tile holding elements are formed by elastic adhesives. This allows for easy positioning and mounting of the magnetic flux guide elements on the carrier element. In some embodiments, the adhesive has a Shore Durometer Type A hardness of 50 or more.

[0023] In one embodiment, the main coil assembly has a stress-free fastening of the magnetic flux guide elements, by means of which forces acting on the main coil assembly are guided past the magnetic flux guide elements. This reduces or eliminates deformation of the support element in the area where the magnetic flux guide elements are held.

[0024] In embodiments, the main coil assembly comprises support elements for transmitting forces in the direction normal to the planes of the support element and the magnetic flux guide elements. When the main coil assembly is arranged in a floor module that is loaded perpendicular to the planes of the magnetic flux guide elements, for example, by a vehicle, loads can be transmitted through the module and the support elements without deforming the support element in the area where the magnetic flux guide elements are attached.

[0025] In some embodiments, the magnetic flux guide elements have a rectangular basic shape, in particular a square basic shape, with at least one recess at each corner. This makes it possible to cover a surface of the main coil to be covered with the magnetic flux guide elements while leaving areas free for the passage of the support elements. In some embodiments, the magnetic flux guide elements have at least two recesses at opposite corners. This increases the variety with which free areas can be arranged between the magnetic flux guide elements.

[0026] In some embodiments, the magnetic flux guide elements have exactly two recesses at opposite corners. This simplifies the assembly of the magnetic flux guide elements, as a predetermined orientation of a magnetic flux guide element can be achieved by rotating it by a maximum of 90°.

[0027] In embodiments, the support elements for spacing the carrier element from other components are each arranged in the region of the recesses of the magnetic flux guide elements.

[0028] In some embodiments, the magnetic flux guide elements all have the same shape. This makes production, warehousing, and repairs more efficient.

[0029] In some embodiments, the carrier element has protruding orientation elements that, after assembly of the magnetic flux guide elements, are located in the region of the recesses and thus define an orientation of the magnetic flux guide elements in the common plane. The orientation elements thus prevent incorrect orientation of the magnetic flux guide elements.

[0030] Further preferred embodiments emerge from the dependent patent claims. The subject matter of the invention is explained in more detail below with reference to preferred embodiments, which are illustrated in the accompanying drawings. They show schematically:

[0031] Figure 1 shows a main coil assembly seen from a first side with a main coil;

[0032] Figure 2 shows the main coil assembly seen from a second side with magnetic flux guiding elements;

[0033] Figure 3 shows a section of the second side view; and Figure 4 shows further details in a view of the second side.

[0034] The reference symbols used in the drawings and their meanings are summarized in the list of reference symbols. In general, identical or equivalent parts are provided with the same reference symbols in the figures.

[0035] Figures 1 and 2 show a main coil assembly 1 viewed from a first and a second side. The main coil assembly 1 is flat, with dimensions between 40 cm by 40 cm and 100 cm by 100 cm. The main coil assembly 1 forms an independent structural unit with a carrier element 5 and a main coil 2 arranged thereon on the first side, and ferrite tiles arranged on the second side, hereinafter referred to as magnetic flux guide elements 4 or ferrites 4. The main coil 2 has one or more current conductors 3, which are guided and / or held in guide and / or holding elements 31. The guide and / or holding elements 31 can be formed integrally on the carrier element 5. The magnetic flux guide elements 4 are tile-shaped and are arranged in at least one plane. They can be arranged in several planes that lie parallel to one another.Figure 2 shows the majority of ferrites 4 in a first plane, directly adjacent to the carrier element 5, with one of the ferrites 4 omitted for clarity. A single ferrite 4 lies in a second plane and covers a gap between ferrites 4 in the first plane. In embodiments not shown, further layers of ferrites 4 can be present, each in its own plane that is parallel to the other planes. The ferrites 4, for example, all have the same shape. In each case, two opposite corners are chamfered, which, with regard to a rectangular shape of the elements, can be referred to as recesses 41. The ferrites 4 are arranged such that recesses 41 of adjacent ferrites 4 lie opposite one another, leaving a larger area free between them.Support elements 55 of the carrier element 5 extend through such regions in a direction normal to the plane of the carrier element 5. If the main coil assembly 1 is arranged in a module with a housing, forces acting on the housing can be diverted through the plane of the carrier element 5 to opposing housing parts. This reduces or eliminates mechanical stress and deformation in the plane of the carrier element 5.

[0036] The two figures also show a cooling medium dividing element 53 which is formed or attached to the carrier element 5 and divides a flow of a cooling medium so that a part flows over the main coil 2 and another part over the ferrites 4.

[0037] Figure 3 shows a partial view of the second side, and Figure 4 shows further details of the same. In addition to the elements already described, tile holding elements 61, positioning elements 62, spacing elements 63, and orientation elements 64 are shown.

[0038] The tile holding elements 61 are elastic. In the illustrated embodiment, they are depicted as adhesive points to which the ferrites 4 can be attached to the carrier element 5. For example, an elastic adhesive can be used for this purpose, or buffers or spacers made of elastic material arranged between the ferrites 4 and the carrier element 5 and firmly connected to them. This allows the ferrites 4 to be mounted or suspended on the carrier element 5 without stress. Due to their elasticity, the tile holding elements 61 absorb different expansions of the carrier element 5 and the ferrites 4 when heated.

[0039] The material of the carrier element 5 has one or more of the following properties: a magnetic permeability of at least approximately one; it is an electrical insulator; it is a poor thermal conductor; it is a plastic,

[0040] The positioning elements 62 define the position of a ferrite 4 by the ferrite 4 resting on the positioning element 62.

[0041] The spacing elements 63 are located between adjacent ferrites 4 and thus define a distance between them. Spacing elements 63 and positioning elements 62 can be formed on the same physical component in that the positioning elements 62 are opposite sides of the component, for example a comb or web, and the comb or web as a whole acts as a spacing element 63.

[0042] Small distances can be achieved by painting at least the adjacent end faces of the magnet executing elements, or by placing a thin, temperature-resistant insulator, for example with aramid fibers, between the ferrites 4.

[0043] The orientation elements 64 protrude beyond a support surface of the carrier element 5, on which the ferrites 4 are placed. This forces the ferrites 4 to be oriented with respect to rotation about the normal to the support surface such that the orientation elements 64 lie in the region of the recesses 41. LIST OF REFERENCE SYMBOLS

[0044] 1 main coil assembly

[0045] 2 main coil

[0046] 3 conductors 10 module

[0047] 31 Guide and / or support element

[0048] 4 Magnetic flux guide element

[0049] 41 Recess

[0050] 5 Support element 53 Cooling medium distribution element

[0051] 55 Support element

[0052] 61 Tile holding element

[0053] 62 Positioning element

[0054] 63 Distancing element 64 Orientation element

Claims

PATENT CLAIMS 1. Main coil assembly (1) for a ground module (GPM) or a vehicle module (CPM) of an inductive charging system for a vehicle, wherein the main coil assembly (1) comprises a main coil (2) and magnetic flux guide elements (4), characterized in that • the magnetic flux guide elements (4) are tile-shaped, • are held by a support element (5), and • are arranged in one or more common levels.

2. Main coil assembly (1) according to claim 1, wherein the carrier element (5) has positioning elements (62) against which the magnetic flux guide elements (4) can be pushed up to a stop during assembly of the magnetic flux guide elements (4) on the carrier element (5), in particular in that the positioning elements (62) define a stop in two mutually orthogonal directions in the common plane.

3. Main coil assembly (1) according to one of the preceding claims, wherein the carrier element (5) has spacing elements (63) which space magnetic flux guide elements (4) mounted on the carrier element (5) apart from one another, in particular with a distance between 10% and 200% of a thickness of the magnetic flux guide elements (4), in particular between 50% and 150% of the thickness.

4. Main coil assembly (1) according to one of the preceding claims, wherein the magnetic flux guide elements (4) are arranged on the carrier element (5) in an individually replaceable manner.

5. Main coil assembly (1) according to one of the preceding claims, comprising tile holding elements (61) with which the magnetic flux guiding elements (4) are resiliently fastened to the carrier element (5), in particular wherein the tile holding elements (61) are elastic elements, in particular wherein the tile holding elements (61) are formed by elastic adhesives.

6. Main coil assembly (1) according to one of the preceding claims, comprising a stress-free fastening of the magnetic flux guide elements (4), by means of which forces acting on the main coil assembly (1) are guided past the magnetic flux guide elements (4).

7. Main coil assembly (1) according to claim 6, comprising support elements (55) for transmitting forces in the direction normal to the planes of the carrier element (5) and the magnetic flux guide elements (4).

8. Main coil assembly (1) according to one of the preceding claims, wherein the magnetic flux guide elements (4) have a rectangular basic shape, each with at least one recess (41) at a corner, in particular at least two recesses (41) at opposite corners, in particular with exactly two recesses (41) at opposite corners.

9. Main coil assembly (1) according to claim 8 as dependent on claim 7, wherein the support elements (55) for spacing the carrier element (5) from other components are each arranged in the region of the recesses (41) of the magnetic flux guide elements (4).

10. Main coil assembly (1) according to one of the preceding claims, wherein the magnetic flux guiding elements (4) all have the same shape.

11. Main coil assembly (1) according to claim 8, wherein the carrier element (5) has protruding orientation elements (64) which, after assembly of the magnetic flux guide elements (4), lie in the region of the recesses (41) and thereby define an orientation of the magnetic flux guide elements (4) in the common plane,

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