Power Transformer Assembly

Abstract

The present invention relates to a power transformer assembly (10) for converting electromagnetic power from an oscillating electromagnetic field into electrical current or usable current power for charging an electrical storage device or energizing an electrical load. The power transformer assembly (10) comprises: a magnetic assembly (MA) for receiving the oscillating electromagnetic field and converting it into alternating current (AC); an electronic assembly (PE) for receiving the alternating current (AC) and converting it into electrical current; and heat dissipation means (X1, X2) for dissipating heat generated by the electronic assembly (PE) during each power conversion operation. The heat dissipation means (X1, X2) comprises a first heat transfer part (X1) associated with said electronic assembly (PE).

Description

[Technical Field]

[0001] The present invention relates to a power transformer assembly for converting electromagnetic power from an oscillating electromagnetic field into electrical power or usable current for charging an electrical storage device or energizing an electrical load. The power transformer assembly comprises a magnetic assembly for receiving the oscillating electromagnetic field and converting it into electrical alternating current, and an electronic assembly for receiving the electrical alternating current and converting it into electrical current or usable current. The power transformer assembly further comprises heat dissipation means for dissipating heat generated by the electronic assembly during each power conversion operation. [Background technology]

[0002] Power transformer assemblies, also known as wireless charger modules, are sometimes used to charge a vehicle's high-voltage (HV) battery. Such modules can receive an oscillating magnetic field from an external transmitter, sometimes called a car pad module (CPM) or ground pad module (GPM), and convert the oscillating electromagnetic field (primarily a magnetic field) into an alternating current (AC), which can then be converted (usually rectified) into a current (usually DC) that is used to charge the HV battery.

[0003] Electric vehicle batteries can be charged using alternating current (AC) or direct current (DC) energy transmission. DC energy transmission is typically done using high-power converters installed at dedicated charging points. DC charging is generally faster than AC charging, but due to the cost of installing DC charging points and the weakness of existing network capacity in the area, DC charging points are generally installed in remote locations and not in homes or residential areas, making them inconvenient for end users.

[0004] On the other hand, AC charging is very important in residential areas and (semi-)public urban areas. A typical AC charger can provide a maximum charging power of 22 kW. AC charging systems can be divided into wired and wireless charging systems, with the latter mainly embodied as inductive charging systems (ICS). Wired AC chargers are generally integrated into electric vehicles and are also called on-board chargers. ICS usually comprise two independent modules called the ground pad module (GPM) and the car pad module (CPM).

[0005] The GPM is installed outside the electric vehicle, while the CPM is installed inside the electric vehicle, usually underneath the vehicle. Electromagnetic interaction between the GPM and CPM allows for energy transfer from the GPM to the CPM, which is then used to charge the electric vehicle's battery. Wireless charging systems are often more convenient for users because no manual operation is required to start the battery charging process, other than parking and positioning the vehicle over the GPM. Wired charging systems, on the other hand, require users to connect their electric vehicle to the power grid with a cable.

[0006] With regard to cooling, it is important to understand that there are two heat generating regions in a CPM: (a) the electronic assembly (power electronics) which generates a lot of heat but in a relatively concentrated area (high density), and (b) the magnetic assembly (coils and ferrites) which generates less heat and which is relatively evenly distributed (low density). Prior art cooling systems for such CPMs are not well suited to this situation and are relatively difficult to manufacture and therefore expensive.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a power transformer assembly with improved overall cooling, and improved cooling of the electronic assembly in particular. Summary of the Invention

[0008] This object is achieved by a power transformer assembly for converting the electromagnetic power of an oscillating electromagnetic field into electrical power or usable electrical current for charging an electrical storage device or energizing an electrical load, the power transformer assembly comprising: a magnetic assembly for receiving an oscillating electromagnetic field and converting it into an electrical alternating current; an electronic assembly for receiving electrical alternating current and converting it into electric current or usable current; and heat dissipation means for dissipating heat generated by the electronic assembly during each power conversion operation; Equipped with The heat dissipation means may comprise a first heat transfer portion associated with the electronic assembly. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS This first heat transfer portion removes concentrated heat from a particular location on the electronic assembly from the electronic assembly. Heat transfer from the electronic assembly may be a combination of radiation, conduction, and convection.

[0010] Preferably, the first heat transfer portion is in thermal contact with the electronic assembly, such that heat transfer from the electronic assembly is due to thermal conduction rather than thermal radiation, and heat transferred by conduction is directed away from the electronic assembly and is more effectively contained than heat transferred by radiation.

[0011] Typically, the electronic assembly comprises power electronics, preferably comprising a number of power electronic components such as diodes, thyristors, power transistors (MOSFETs and / or IGFTs).

[0012] In a preferred embodiment, an array of electronic components of the electronic assembly extends along a first smoothed virtual reference surface within a first volume defined by the first virtual reference surface and a first virtual thickness extending in a direction perpendicular to the first reference surface. Preferably, the first smoothed virtual reference surface has at least one of a flat surface portion, a surface portion having one-dimensional curvature, and a surface portion having two-dimensional curvature. and thus defines a plate- and / or shell-shaped first volume having an edge-like periphery and comprising said electronic assembly.

[0013] Because all heat generated by the electronic assembly originates from this plate- or shell-like first volume, the distance from any point within the first volume to the nearest boundary point of the first volume is very short. The maximum such distance is half the thickness of the first volume if either of the two large boundary surfaces can be selected as the boundary point. If only one of the two large boundary surfaces can be selected as the boundary point, the maximum such distance is one (full) thickness of the first volume. As a result, the thermal resistance within the imaginary first volume around the electronic assembly is low, and heat generated by the electronic assembly is easily removed from the electronic assembly by thermal conduction.

[0014] Preferably, the heat dissipation means comprises a second heat transfer portion associated with the magnetic assembly. This second heat transfer section allows less, relatively well-distributed heat (less concentrated heat) to be removed from the magnetic assembly from a particular location on the magnetic assembly. Again, heat transfer from the magnetic assembly may be a combination of radiation, conduction and convection.

[0015] Preferably, the second heat transfer portion is in thermal contact with the magnetic assembly, again resulting in heat transfer from the magnetic assembly by thermal conduction rather than thermal radiation, with heat transferred by conduction being directed away from the magnetic assembly and more effectively contained than heat transferred by radiation.

[0016] In a further preferred embodiment, the coil topology of the magnetic assembly extends along a second smoothed virtual reference plane within a second volume defined by said second virtual reference plane and a second virtual thickness extending in a direction perpendicular to said second reference plane.

[0017] Preferably, the second smoothed virtual reference surface comprises at least one of a planar surface portion, a surface portion having one-dimensional curvature and a surface portion having two-dimensional curvature, and thus defines a plate- and / or shell-shaped second volume having an edge-like periphery and comprising the magnetic assembly.

[0018] Again, because all heat generated by the magnetic assembly originates from this plate- or shell-like second volume, the distance from any point within the second volume to the nearest boundary point of the second volume is very short. The maximum such distance is half the thickness of the second volume if either of the two large boundary surfaces can be selected as the boundary point. If only one of the two large boundary surfaces can be selected as the boundary point, the maximum such distance is one (full) thickness of the second volume. As a result, the thermal resistance within the imaginary second volume around the magnetic assembly is low, and heat generated by the magnetic assembly is easily removed from the magnetic assembly by thermal conduction.

[0019] In a further preferred embodiment, the heat dissipation means comprises a cooling water circuit in which the first heat transfer portion is a part of the cooling water circuit. This cooling water circuit allows concentrated heat originating from the electronic assembly and removed from the electronic assembly mainly by conduction to be further removed by forced convection, i.e. by cooling fluid pumped through the cooling water circuit.

[0020] Preferably, the electronic assembly and the first volume surrounding it are arranged adjacent to the edge-like periphery of the second volume constituting the magnetic assembly. This edge-to-edge arrangement of the first volume and the second volume of the electronic assembly and the magnetic assembly, i.e., non-stacked arrangement, contributes to reducing the overall thickness of the power transformer assembly, which in turn reduces the thickness of the ground pad module (GPM) comprised of such a power transformer assembly, allowing it to maintain a low profile when attached to the underside of an electric vehicle.

[0021] Preferably, the cooling water circuit extends along at least a portion of the edge-like periphery of the second volume comprising the magnetic assembly, which contributes to the compactness of a ground pad module (GPM) comprising such a power transformer assembly and also facilitates the mounting of the GPM on the underside of an electric vehicle.

[0022] In a further preferred embodiment, the first heat transfer portion extends along a third smoothed virtual reference surface within a third volume defined by the third virtual reference surface and a third virtual thickness extending in a direction perpendicular to the third reference surface. Preferably, the third smoothed virtual reference surface comprises at least one of a planar surface portion, a surface portion having one-dimensional curvature, and a surface portion having two-dimensional curvature, and thus defines a plate-like and / or shell-like third volume having an edge-like periphery, and comprises the first heat transfer portion.

[0023] Because all heat originates from the electronic assembly, i.e., the first volume, and enters the first heat transfer section, i.e., the third volume, the distance from any point within the third volume to the nearest boundary point of the third volume is very short. The maximum value of such distance is half the thickness of the second volume if either of the two large boundary surfaces can be selected as the boundary point. The maximum value of such distance is one (full) thickness of the second volume if only one of the two large boundary surfaces can be selected as the boundary point. As a result, the thermal resistance within the imaginary third volume around the first heat transfer section is low, and heat generated by the electronic assembly is easily removed from the electronic assembly by thermal conduction and forced convection within the first heat transfer section, i.e., the third volume.

[0024] In another preferred embodiment, a) on the one hand, the array of electronic components of the electronic assembly extending within the first volume defined by the first virtual reference plane and the first virtual thickness perpendicular to the first reference plane, and b) on the other hand, the first heat transfer portion extending within the third volume defined by the third virtual reference plane and the third virtual thickness perpendicular to the third reference plane, are thermally associated with each other.

[0025] Preferably, a) the arrangement of the electronic components of the electronic assembly and b) the first heat transfer portion are arranged in a stacked relationship adjacent to each other with the first virtual reference plane and the third virtual reference plane in close proximity. The electronic assembly corresponding to the first volume and the first heat-transfer portion corresponding to the third volume are laminated plates (flat surfaces) or laminated shells (curved surfaces). Regardless of its shape (flat or curved), this compact stacked relationship between the electronic assembly and the first heat transfer portion improves heat transfer between the electronic assembly and the first heat transfer portion, which may be part of a cooling water circuit.

[0026] Preferably, the first heat transfer portion is a duct portion of the cooling water circuit, which, as already mentioned above, allows heat from the electronic assembly to be efficiently removed by conduction and forced convection. Preferably, the duct portion includes a plurality of protrusions extending in a direction perpendicular to the main cooling water flow direction within the duct portion. Preferably, the plurality of protrusions fit into a first inner wall of the duct portion and extend towards a second inner wall of the duct portion opposite the first inner wall. Preferably, the plurality of protrusions are pin-like formations. All of this contributes to increasing the surface area of ​​the cooling water / duct portion interface and therefore increasing the heat flow across this interface, i.e., from the electronic assembly to the duct portion and to the cooling water within said duct portion.

[0027] Preferably, each of the protrusions has a protrusion axis, and the protrusion axes of all the protrusions are parallel to one another. Preferably, each said projection is tapered in cross section decreasing along the projection axis from a larger cross section at the projection root to a smaller cross section at the projection tip. The tapered protrusions may be frustoconical or frustopyramidal. If such a duct portion with projections is produced by injection molding or die casting, the molded product can be easily demolded.

[0028] Preferably, the protrusions of said plurality of projections have a cross section selected from at least one of circular, oval, elliptical and polygonal. Preferably, the cross section is a regular hexagon or a rhombus (diamond). Both of these cross-sectional shapes help prevent the formation of dead zones in the cooling water flow and again contribute to increasing the surface area of ​​the cooling water / duct portion interface, thus increasing the heat flow across this interface, i.e., from the electronic assembly to the duct portion and to the cooling water within said duct portion. Preferably, the plurality of protrusions comprise protrusions having different shapes and / or different sizes. This allows the free space between the larger protrusions to be partially filled with smaller protrusions, again increasing the surface area of ​​the coolant / duct section interface, but also reducing the effective duct cross-sectional area for coolant flow. As a result, by varying at least one of the protrusion size, protrusion shape, and protrusion packing density, it is possible to adjust both the cooling performance and the coolant pressure drop along the duct section.

[0029] Preferably, the plurality of protrusions are arranged in a staggered pattern with respect to the main flow direction. This can prevent dead zones from forming in the coolant flow and can also prevent short circuits with the coolant flow pattern.

[0030] Preferably, a) a first plurality of protrusions of the plurality of protrusions engage a first inner wall of the duct portion and extend towards a second inner wall of the duct portion opposite the first inner wall, and b) a second plurality of protrusions of the plurality of protrusions engage the second inner wall of the duct portion and extend towards the first inner wall of the duct portion opposite the second inner wall. Again, this helps prevent dead zones from forming in the coolant flow and also helps prevent short circuits with the coolant flow pattern. Also, if the duct portion or the entire cooling water circuit with the duct portion is made by molding, this allows the duct portion or the entire cooling water circuit to be made from two identical parts or "halves" that can be fitted together to obtain the duct portion or cooling water circuit.

[0031] Preferably, the length of each of the projections along the projection axis is less than the duct width along the projection axis between the first inner wall and the opposing second inner wall. This allows manufacturing tolerances to be compensated for and therefore prevents any of the protrusions being too long which may interfere with the fit of two complementary moulded parts of the duct section or the entire cooling water circuit. Preferably, the protrusion is hollow. This not only reduces the weight of the duct section or the entire cooling water circuit, but also the amount of material required to manufacture the duct section or the entire cooling water circuit. Furthermore, the hollow space of the hollow protrusion is suitable for providing fixing means such as fixing screws or bolts extending within the hollow protrusion, preferably along the protrusion axis, and through holes in the tip of said protrusion.

[0032] Preferably, the cooling water circuit having the first heat transfer portion is made by forming (molding) a material in a mold. Preferably, the cooling water circuit with the first heat transfer portion is made by molding (casting, pouring) a moldable material in the mold or in the mold. Preferably, the cooling water circuit having the first heat transfer portion is made by sintering a sinterable material in the mold. Preferably, the cooling water circuit having the first heat transfer portion is made by cross-linking a cross-linkable material in the mold.

[0033] Preferably, the cooling water circuit having the first heat transfer portion is made additively layer by layer. [Brief explanation of the drawings]

[0034] 1 to 5 show one embodiment of a power transformer assembly according to the present invention. FIG. 1 shows a top, partially cut-away view of a power transformer assembly according to the present invention. FIG. 2 shows a perspective view of a first portion (bottom portion of the protrusion) of a cutaway portion of the power transformer assembly of FIG. FIG. 3 shows a perspective view of a second portion (top portion without protrusions) of the cutaway portion of the power transformer assembly of FIG. FIG. 4 shows a first cross section of the cutaway portion of the power transformer assembly of FIG. 1, taken perpendicular to the main cooling water flow direction. FIG. 5 shows a first cross section of the cutaway portion of the power transformer assembly of FIG. 1, taken perpendicular to the main cooling water flow direction.

Claims

1. A power transformer assembly (10) for converting electromagnetic power of an oscillating electromagnetic field into electrical current or usable electrical power for charging an electrical storage device or energizing an electrical load, comprising: a magnetic assembly (MA) for receiving said oscillating electromagnetic field and converting it into electrical alternating current (AC); an electronic assembly (PE) for receiving said electrical alternating current (AC) and converting it into said current; heat dissipation means (X1, X2) for dissipating heat generated by said electronic assemblies (PE) during their respective power conversion operations; A power transformer assembly, characterized in that said heat dissipation means (X1, X2) comprise a first heat transfer part (X1) associated with said electronic assembly (PE).

2. 2. A power transformer assembly according to claim 1, wherein said first heat transfer part (X1) is in thermal contact with said electronic assembly (PE).

3. 3. A power transformer assembly according to claim 1 or 2, wherein the electronic assembly (PE) consists of power electronics and preferably comprises a plurality of power electronic components.

4. 4. The power transformer assembly of claim 1, wherein an arrangement of electronic components of the electronic assembly (PE) extends along a first smoothed imaginary reference plane within a first volume defined by the first imaginary reference plane and a first imaginary thickness extending in a direction perpendicular to the first reference plane.

5. 5. The power transformer assembly of claim 4, wherein the first smoothed virtual reference surface comprises at least one of a planar surface portion, a surface portion having one-dimensional curvature, and a surface portion having two-dimensional curvature, and thus defines a plate-like and / or shell-like first volume having an edge-like circumference and comprising the electronic assembly (PE).

6. 6. A power transformer assembly according to any one of claims 1 to 5, wherein said heat dissipation means (X1, X2) comprises a second heat transfer portion (X2) associated with said magnetic assembly (MA).

7. 7. A power transformer assembly according to claim 6, characterized in that said second heat transfer part (X2) is in thermal contact with said magnetic assembly (MA).

8. 8. The power transformer assembly of claim 1, wherein a coil topology of the magnetic assembly (MA) extends along a second smoothed imaginary reference plane within a second volume defined by the second imaginary reference plane and a second imaginary thickness extending in a direction perpendicular to the second reference plane.

9. 9. The power transformer assembly of claim 8, wherein the second smoothed virtual reference surface comprises at least one of a planar surface portion, a surface portion having one-dimensional curvature, and a surface portion having two-dimensional curvature, and thus defines a plate-like and / or shell-like second volume having an edge-like circumference, and comprising the magnetic assembly (MA).

10. Transformer assembly according to any one of claims 1 to 9, characterized in that the heat dissipation means (X1, X2) comprise a cooling water circuit (CC), and the first heat transfer part (X1) is part of the cooling water circuit (CC).

11. 11. A power transformer assembly according to claim 10, wherein said electronic assembly (PE) is disposed adjacent to said peripheral circumference of said second volume containing said magnetic assembly (MA).

12. 12. A power transformer assembly according to claim 10 or 11, wherein said cooling water circuit (CC) extends along at least a part of said peripheral circumference of said second volume containing said magnetic assembly (MA).

13. 13. The power transformer assembly of claim 1, wherein the first heat-transfer portion (X1) extends along a third smoothed imaginary reference plane within a third volume defined by the third imaginary reference plane and a third imaginary thickness extending in a direction perpendicular to the third reference plane.

14. 14. The power transformer assembly of claim 13, wherein the third smoothed virtual reference surface comprises at least one of a planar surface portion, a surface portion having one-dimensional curvature, and a surface portion having two-dimensional curvature, and thus defines a plate- and / or shell-shaped third volume having an edge-like periphery, and comprises the first heat-transfer portion (X1).

15. a) on the one hand, an arrangement of the electronic components of the electronic assembly (PE) extending within the first volume defined by the first imaginary reference plane and the first imaginary thickness orthogonal to the first reference plane; b) on the other hand, the first heat transfer portion (X1) extending within the third volume defined by the third virtual reference plane and the third virtual thickness perpendicular to the third reference plane; 15. A power transformer assembly according to claim 13 or 14, which is thermally related to one another.

16. a) an arrangement of the electronic components of the electronic assembly (PE); b) the first heat transfer portion (X1), 16. The power transformer assembly of claim 15, wherein the first virtual reference plane and the third virtual reference plane are disposed closely adjacent one another in a stacked relationship (PE-X1). (→PE and X1 are laminated plates (flat) or laminated shells (curved))

17. 17. A power transformer assembly according to any one of claims 1 to 16, characterized in that the first heat transfer portion (X1) is a duct portion (CC1) of the cooling water circuit (CC).

18. 18. The power transformer assembly of claim 17, wherein the duct portion (CC1) comprises a plurality of protrusions (P) extending transversely to a main cooling water flow direction (F) within the duct portion (CC1).

19. 20. The power transformer assembly of claim 18, wherein the plurality of protrusions (P) fit into a first inner wall (IW1) of the duct portion (CC1) and extend toward a second inner wall (IW2) of the duct portion (CC1) opposite the first inner wall (IW1).

20. 20. A power transformer assembly according to claim 18 or 19, wherein said plurality of protrusions (P) are pin-like formations.

21. 21. A power transformer assembly according to claim 20, wherein each of said protrusions (P) has a protrusion axis (PA), and the protrusion axes (PA) of all protrusions (P) are parallel to each other.

22. 22. A power transformer assembly according to claim 20 or 21, wherein each of said protrusions (P) is tapered in cross section along the protrusion axis (PA) from a larger cross section (CPR) at the protrusion root (PR) to a smaller cross section (CPT) at the protrusion tip (PT). (→Truncated cone / frustum of a cone or truncated pyramid / frustum of a pyramid)

23. 22. A power transformer assembly according to claim 20 or 21, wherein the protrusions (P) of the plurality of projections have a cross section selected from at least one of the following: circular, oval, elliptical and polygonal.

24. 23. The power transformer assembly of claim 22, wherein the cross section is a regular hexagon or a diamond.

25. 25. A power transformer assembly according to any one of claims 18 to 24, wherein the plurality of protrusions (P) comprise projections having different shapes and / or different sizes.

26. 26. A power transformer assembly according to any one of claims 18 to 25, wherein the plurality of protrusions (P) are arranged in a staggered manner with respect to the main water flow direction (F).

27. a) a first plurality of protrusions of the plurality of protrusions (P) engage with a first inner wall (IW1) of the duct portion (CC1) and extend toward a second inner wall (IW2) of the duct portion (CC1) opposite the first inner wall (IW1); b) a second plurality of protrusions of the plurality of protrusions (P) are fitted into the second inner wall (IW2) of the duct portion (CC1) and extend toward the first inner wall (IW1) opposite to the second inner wall (IW2) of the duct portion (CC1); 27. A power transformer assembly according to any one of claims 18 to 26.

28. 28. A power transformer assembly according to any one of claims 21 to 27, wherein a length of each of the protrusions (P) along the protrusion axis (PA) is less than a duct width (DW) along the protrusion axis (PA) between the first inner wall (1W1) and the opposing second inner wall (1W2).

29. 29. A power transformer assembly according to any one of claims 18 to 28, wherein said protrusion (P) is hollow.

30. 30. Power transformer assembly according to any one of claims 10 to 29, wherein the cooling water circuit (CC) with the first heat transfer portion (X1) is made by forming (molding) a material in a mold.

31. 31. The power transformer assembly according to claim 30, wherein the cooling water circuit (CC) having the first heat transfer portion (X1) is made by molding (casting, injecting) a moldable material into the mold.

32. 31. A power transformer assembly according to claim 30, wherein the cooling water circuit (CC) having the first heat transfer portion (X1) is made by sintering a sinterable material in the mold.

33. 31. The power transformer assembly according to claim 30, wherein the cooling water circuit (CC) having the first heat transfer portion (X1) is made by cross-linking a cross-linkable material in the mold.

34. 30. A power transformer assembly according to any one of claims 10 to 29, wherein the cooling water circuit (CC) with the first heat transfer portion (X1) is made additively layer by layer.

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