Wireless charging module comprising a cooling channel
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- BRUSA ELEKTRONIK AG
- Filing Date
- 2024-07-01
- Publication Date
- 2026-05-13
AI Technical Summary
Wireless charging modules for electric vehicles face challenges in efficiently dissipating heat generated by electronic and magnetic assemblies, leading to potential thermal management issues that can affect charging efficiency and reliability.
A wireless charging module with a cooling system featuring a coolant channel structure and flow guide elements with specific dimensions and cross-sections that promote turbulent coolant flow, enhancing heat transfer between the coolant and heat-generating components.
The solution effectively accelerates coolant flow and increases heat transfer, improving thermal management and maintaining efficient charging performance while minimizing pressure drop.
Smart Images
Figure EP2024068434_16012025_PF_FP_ABST
Abstract
Description
[0001] WIRELESS CHARGING MODULE WITH COOLING DUCT
[0002] The present invention relates to a wireless charging module for charging a battery or powering a consumer of a vehicle. 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 being implemented as inductive charging systems (ICS). Wired AC chargers are typically integrated into electric vehicles and are also referred to as on-board chargers. 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 attached inside the electric vehicle, usually on the underside of the vehicle.The electromagnetic interaction between the GPM and the CPM enables energy transfer from the GPM to the CPM and vice versa, and the CPM is, in turn, used to charge an electric vehicle's battery. Wireless charging systems are often more convenient for the user, as no manual intervention is typically required to initiate battery charging, other than parking the vehicle over the GPM.
[0003] The wireless charging module according to the invention can be used in particular for charging a high-voltage battery or for powering a consumer of a vehicle. In this case, it can be referred to as a car pad module (CPM). This can receive an oscillating magnetic field from an external transmitter, which can be referred to as a ground pad module (GPM). The CPM converts the oscillating electromagnetic, predominantly magnetic, field into an alternating current, which is converted (typically rectified) and thus becomes a charging current (typically direct current) used to charge the battery or power the consumer.
[0004] The wireless charging module can also be referred to as a power conversion assembly. It is used to convert the electromagnetic power of an oscillating electromagnetic field into electrical power, an electric current, or an available electric current, for charging an electrical storage device or powering an electrical load.
[0005] With regard to cooling, it is important to understand that a CPM can have two areas of heat generation: an electronic assembly (power electronics), which generates a lot of heat but is concentrated in specific locations of the device, where it has a relatively high density of heat-generating elements; and a magnetic assembly (coil and ferrite), which generates less heat and is spatially relatively widely distributed, thus having a low density of heat-generating elements. The object of the invention is to create a wireless charging module of the type mentioned above, which has improved heat transfer from heat-generating elements to a cooling medium for cooling the charging module.
[0006] This problem is solved by a wireless charging module having the features of patent claim 1.
[0007] The wireless charging module is used to charge a vehicle's battery and / or power a vehicle's consumer and / or deliver energy from the vehicle's battery and / or deliver energy from a vehicle's energy source. It comprises:
[0008] • a first, in particular magnetic, assembly for receiving an oscillating electromagnetic field and converting it into an alternating electrical current;
[0009] • a second, in particular electronic, assembly for receiving the alternating electrical current and converting it into an electrical current for charging the traction battery, and
[0010] • a cooling system for dissipating heat generated by the two assemblies during their operation by means of a coolant flow.
[0011] The cooling system has a cooling channel structure with at least one coolant channel and with at least two flow guide elements extending transversely to a flow direction,
[0012] • wherein a width of the flow guiding elements is greater than a distance between the flow guiding elements.
[0013] This relationship between the width of the flow guide elements and the distances between the flow guide elements leads to an acceleration of the coolant flow in the spaces between the flow guide elements, and this in turn to a turbulent flow. This turbulence takes place in the area between the flow guide elements and increases the heat transfer between the coolant flow and the flow guide elements.
[0014] The statement that the width of the flow guide elements is greater than the distance between them can also be formulated as follows: Viewed in a plane perpendicular to the flow direction, the flow guide elements each extend along a first direction, and in a second direction perpendicular to the first direction, the width of the flow guide elements is greater than the distance between the flow guide elements. The distance is equal to the width of a passage between the flow guide elements.
[0015] In embodiments, the width of the flow guide elements in the second direction, viewed in the plane normal to the flow direction, is greater than the distance between an outer flow guide element and a channel wall adjacent to it. Thus, the above-described turbulence with the improved heat transfer is also realized in the edge region of a row of flow guide elements.
[0016] In embodiments, the width of the flow guide elements is at least one and a half times, in particular at least twice, in particular at least three times greater than a distance between the flow guide elements.
[0017] This further increases the turbulence and heat transfer to the flow guide elements. Although the pressure drop between the flow guide elements is also higher with the smaller distance, the pressure drop between the flow guide elements is also higher because fewer flow guide elements are required overall due to the higher heat transfer. This means that the pressure drop can be comparable or smaller for the same heat transfer. In embodiments, the flow guide elements, viewed in a plane (hereinafter referred to as the flow plane) that is parallel to the flow direction and parallel to the second direction, have an at least approximately semicircular cross-section on their side facing the flow. In particular, they also have an at least approximately semicircular cross-section on their side facing away from the flow.
[0018] More precisely, it may be the case that the flow guide elements, viewed in a plane (hereinafter referred to as the flow plane) that is parallel to the flow direction and parallel to the second direction, have an at least approximately semicircular cross-section on their side facing the flow. Since the flow plane is parallel to the second direction, it runs perpendicular to the first direction.
[0019] In embodiments, the flow guiding elements have a circular cross-section.
[0020] This enables a particularly simple design of the flow guidance elements.
[0021] In embodiments, the flow guide elements have an oval cross-section or an egg-shaped cross-section.
[0022] This, as well as the shape described below, allows the area of turbulence and improved heat transfer along the flow guide elements to be extended.
[0023] In embodiments, the flow guide elements are arranged in a curved section of the coolant channel, and a length of the flow guide elements in the flow direction is greater than a width of the flow guide elements normal to the flow direction, and in an intermediate region or passage between the flow guide elements, which extends in the flow direction, the distance between the flow guide elements at different locations in the intermediate region is substantially the same.
[0024] This means that the inventive concept can also be implemented in a curved area.
[0025] In embodiments, a length of the flow guiding elements in the flow direction is less than two and a half times a width of the flow guiding elements normal to the flow direction, and in particular at least approximately equal to twice.
[0026] This allows for at least approximately optimum heat transfer. In some embodiments, the length of the flow guide elements in the flow direction is greater than one and a half times the width of the flow guide elements.
[0027] In embodiments, the flow guide elements extend from a first inner wall of the coolant channel to or at least approximately to an opposite second inner wall.
[0028] Thus, the flow guiding elements can be attached or arranged on the first inner wall, and the design and manufacture of the second inner wall is simplified.
[0029] In embodiments, the flow guide elements are made of a metal.
[0030] This allows for good thermal conductivity of the flow guide elements. In some embodiments, the flow guide elements are formed integrally on a metal inner wall of the coolant channel.
[0031] This allows for effective heat transfer from the inner wall to the flow guide elements. Typically, a part where the inner wall is formed is arranged to absorb heat from a component to be cooled.
[0032] In embodiments, the flow guide elements are inserted into an inner wall of the coolant channel formed from a non-metallic material and guided to a heat transfer body which is arranged to absorb heat from an assembly which generates heat during operation and which is to be cooled.
[0033] This allows for good heat transfer from the inner wall to the heat-generating and cooled assembly, even if the channel wall is made of a body with poor heat conduction.
[0034] In embodiments, the coolant channel has at least one cooling section, and the flow guide elements are arranged in this cooling section for dissipating heat from an assembly that generates heat during operation and is to be cooled, in particular from at least one of the magnetic assembly and the electronic assembly.
[0035] In embodiments, the coolant channel has a substantially rectangular cross-section, the extent of which along the first direction is referred to below as the height, and the extent of which along the second direction is referred to below as the width, wherein the width is at least three times the height. In embodiments, the cooling channel structure is arranged between at least a first part and a second part, and one or more channels of the cooling channel structure are formed by recesses in the first part and / or the second part. In particular, the first part and / or the second part are plate-like or flat.
[0036] The first part and the second part each form a half-shell, which when placed together form the cooling channel structure with one or more coolant channels.
[0037] In embodiments, the first and second cooling sections are arranged on coolant channels running parallel to one another.
[0038] In embodiments, the first and second cooling sections are arranged at successive locations along the same coolant channel in the flow direction.
[0039] Therefore, there can be two or more cooling sections. If there is only one coolant channel, the cooling sections are arranged along this coolant channel. If there are two or more coolant channels, the cooling sections can be arranged along different coolant channels.
[0040] In embodiments, at least one of the first part and the second part forms a supporting structure that supports at least one of the magnetic and electronic assemblies.
[0041] In embodiments, at least one of
[0042] • the magnetic assembly is mounted adjacent to a first cooling section, and optionally also adjacent to a second cooling section, on the first part or on the second part;
[0043] • the electronic assembly is mounted adjacent to the second cooling section, on the first part, or on the second part. Further preferred embodiments are set out in the dependent claims.
[0044] 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:
[0045] Figure 1 shows a garage with a vehicle on a wireless charging station;
[0046] Figure 2 shows a wireless charging station and a wireless charger;
[0047] Figure 3 a wireless charger;
[0048] Figure 4 shows a cross-section through a wireless charger;
[0049] Figure 5 shows a section of a similar cross-section, with flow guidance elements;
[0050] Figure 6 shows a cooling section with flow guiding elements;
[0051] Figure 7 shows the flow around flow guidance elements.
[0052] The reference symbols used in the drawings and their meanings are summarized in the list of reference symbols. In general, identical or functionally equivalent parts are provided with the same reference symbols in the figures.
[0053] Figure 1 shows a top view of a garage 1 in which a vehicle 2 is parked above a wireless charging station 3 located outside the vehicle 2 and equipped with a transmitter for transmitting an oscillating magnetic field. The charging station 3 is visible because the vehicle 2 is shown transparently. Such a charging solution is very convenient and saves the driver from having to plug and unplug a charging cable.
[0054] Figure 2 is an enlargement of Figure 1 and shows the wireless charging station 3 and a wireless charger 4 "floating" above the charging station 3 for charging a high-voltage battery 5 of the vehicle 2. The charger 4 is built into the vehicle, meaning the rest of the vehicle is not visible in this view. Figure 3 shows a perspective view of the charger 4.
[0055] Figure 4 shows a schematic cross-section through a wireless charger 4, which can also be referred to as a wireless charging module. A first part 41 and a second part 42 form a supporting structure for the other components described. The first part 41 and / or second part 42 can themselves be composed of several individual parts. A housing (not shown) can also be present. An electronic assembly 7 is arranged on the first part 41. This leads to relatively high waste heat in a relatively small space. A magnetic assembly 6 is arranged on or in the second part 42. This assembly has coil conductors 62 and ferrite elements 61. These, distributed over a larger space, lead to comparatively lower waste heat.
[0056] Between the first part 41 and the second part 42, coolant channels 90 of a cooling channel structure 9 are formed by recesses in one or both of these parts. The coolant channels 90 can be sealed by sealing elements 49. The coolant channels 90 comprise a first cooling section 91, which primarily cools parts of the magnetic assembly 6, and a second cooling section 92, which cools the electronic assembly 7 and, in this embodiment, also parts of the magnetic assembly 6. The second cooling section 92 is therefore designed to dissipate a larger amount of heat per unit of time than the first cooling section 91.
[0057] The first cooling section 91 has a smooth wall structure 43. The second cooling section 92 has a structured wall structure 44. Because the structured wall structure 44 leads to higher heat transfer than the smooth wall structure 43, and / or because the coolant flow in the second cooling section 92 is higher than in the first cooling section 91, a greater amount of heat is dissipated by the second cooling section 92. The structured wall structure 44 is designed in the form of swirling structures or flow guide elements 45 that protrude into the coolant channel 90.
[0058] Figures 5, 6, and 7 show the arrangement of flow guide elements 45 in the coolant flow 80 of a coolant channel 90. In Figure 5, not all parts of the cross-section are as shown in Figure 4. Figure 6 is a wireframe representation of various types of flow guide elements 45 in a section of a coolant channel 90. The flow guide elements 45 are formed on or inserted into the second part 42. They extend from a first inner wall 94 of the coolant channel 90 to, or at least approximately to, an opposite second inner wall 95. In other embodiments, the flow guide elements 45 extend from the first part 41 toward the second part 42.
[0059] Viewed in the direction of the coolant flow 80, the width of the flow guide elements 45 is greater than the distance between the flow guide elements 45. Alternatively or additionally, the width of an outer flow guide element 45 is greater than the distance between the outer flow guide elements 45 and a respective nearest lateral inner wall 96 of the coolant channel 90. The aforementioned distances are each equal to the width of a passage between two flow guide elements 45 or between an outer flow guide element 45 and the nearest lateral inner wall 96. The described relationship between width and distance leads to high acceleration and a turbulent or highly swirling flow between the flow guide elements 45 or between an outer flow guide element 45 and the nearest lateral inner wall 96.This in turn leads to a greatly improved heat transfer from the coolant flow 80 to the flow guide elements 45 or the respective lateral inner wall 96. In Figure 6, the flow guide elements 45 in the right-hand row are circular-cylindrical, i.e., they have a circular cross-section. The flow guide elements 45 in the left-hand row have an oval cross-section. As a result, the length of the flow guide elements 45 in the flow direction becomes greater than the width, and the area in which the turbulent flow is in contact with the flow guide element 45 increases. As the length increases, the turbulence between the flow guide elements 45 decreases, and with it the heat transfer. A preferred ratio between width and length is therefore at least approximately one to two.
[0060] The combination of the various cross-sections shown in Figure 6 is merely exemplary. In embodiments, one or more rows of flow guide elements, each with the same cross-section, are present. In embodiments, the coolant channel curves around a bend, and the flow guide elements 45 have cross-sections in the shape of curved ovals, so that passages or intermediate regions located between the flow guide elements 45 have a substantially constant cross-section.
[0061] Figure 7 visualizes the turbulence of the coolant flow 80 through the flow guide elements 45. Light areas of the flow correspond to weak turbulence, with a laminar or stationary flow. Dark areas correspond to strong turbulence. These areas are located in the area of the passages between the flow guide elements 45 and lead to good heat transfer.
[0062] LIST OF REFERENCE SYMBOLS
[0063] 1 garage
[0064] 2 vehicles
[0065] 3 charging stations
[0066] 4 wireless charger 41 first part
[0067] 42 second part
[0068] 43 smooth wall structure
[0069] 44 structured wall structure
[0070] 45 Flow guide element
[0071] 46 flow side
[0072] 47 side facing away from the current
[0073] 49 Sealing element
[0074] 5 Battery
[0075] 6 magnetic assembly
[0076] 61 ferrite elements
[0077] 62 coil conductors
[0078] 7 electronic assembly
[0079] 8 Cooling system
[0080] 80 coolant flow
[0081] 81 first coolant connection
[0082] 82 second coolant connection
[0083] 9 Cooling channel structure
[0084] 90 coolant channel
[0085] 91 first cooling section
[0086] 92 second cooling section
[0087] 94 first interior wall
[0088] 95 second interior wall
[0089] 96 side inner wall
Claims
PATENT CLAIMS 1. Wireless charging module for charging a battery (5) of a vehicle (2) and / or for supplying a consumer of the vehicle (2) and / or for delivering energy from the battery (5) of the vehicle (2) and / or for delivering energy from an energy source of the vehicle (2), with • a first, in particular magnetic, assembly (6) for receiving an oscillating electromagnetic field and converting it into an alternating electrical current; • a second, in particular electronic, assembly (7) for receiving the alternating electrical current and converting it into an electrical current for charging the battery (5) or for supplying the consumer, • a cooling system (8) for dissipating heat generated by the two assemblies (6, 7) during their operation by means of a coolant flow (80); • wherein the cooling system (8) has a cooling channel structure (9) with at least one coolant channel (90) and with at least two flow guide elements (45) extending transversely to a flow direction, • wherein a width of the flow guide elements (45) is greater than a distance between the flow guide elements (45).
2. Wireless charging module (4) according to claim 1, wherein the width of the flow guide elements (45) is at least one and a half times, in particular at least twice, in particular at least three times greater than a distance between the flow guide elements (45).
3. Wireless charging module (4) according to one of the preceding claims, wherein the flow guiding elements (45) are arranged at their side facing the flow facing side (46) have an at least approximately semicircular cross-section, and in particular on their side facing away from the flow (47) also have an at least approximately semicircular cross-section.
4. Wireless charging module (4) according to claim 3, wherein the flow guide elements (45) have a circular cross-section.
5. Wireless charging module (4) according to claim 3, wherein the flow guide elements (45) have an oval cross-section or an egg-shaped cross-section.
6. Wireless charging module (4) according to claim 3, wherein the flow guide elements (45) are arranged in a curved section of the coolant channel (90), and a length of the flow guide elements (45) in the flow direction is greater than a width of the flow guide elements (45) normal to the flow direction, and in an intermediate region between the flow guide elements, which extends in the flow direction, the distance between the flow guide elements (45) at different locations in the intermediate region is substantially the same.
7. Wireless charging module (4) according to claim 5 or 6, wherein a length of the flow guide elements (45) in the flow direction is less than two and a half times a width of the flow guide elements (45) normal to the flow direction, and in particular at least approximately equal to twice.
8. Wireless charging module (4) according to one of the preceding claims, wherein the flow guide elements (45) extend from a first inner wall (94) of the coolant channel (90) to or at least approximately to an opposite second inner wall (95).
9. Wireless charging module (4) according to one of the preceding claims, wherein the flow guide elements (45) are made of a metal.
10. Wireless charging module (4) according to claim 9, wherein the flow guide elements (45) are formed integrally on an inner wall of the coolant channel (90) made of metal.
11. Wireless charging module (4) according to claim 9, wherein the flow guide elements (45) are inserted into an inner wall of the coolant channel (90) formed from a non-metallic material and are guided to a heat transfer body which is arranged to absorb heat from an assembly (6, 7) which generates heat during operation and is to be cooled.
12. Wireless charging module (4) according to one of the preceding claims, wherein the coolant channel (90) has at least one cooling section (91, 92), and the flow guide elements (45) are arranged in this cooling section (91, 92) for dissipating heat from an assembly (6, 7) that generates heat during operation and is to be cooled, in particular from at least one of the magnetic assembly (6) and the electronic assembly (7).
13. Wireless charging module (4) according to one of the preceding claims, wherein the coolant channel has a substantially rectangular cross-section, the extent of which along the first direction is hereinafter referred to as height and the extent of which along the second direction is hereinafter referred to as width, the width being at least three times the height.
14. Wireless charging module (4) according to one of the preceding claims, wherein the cooling channel structure is arranged between at least a first part (41) and a second part (42) and one or more channels of the cooling channel structure (9) are formed by recesses in the first part (41) and / or in the second part (42), in particular wherein the first part (41) and / or the second part (42) are plate-like or flat.