DE102019130089A1 - Device for inductive charging of a vehicle battery - Google Patents

Abstract

The invention relates to a device for inductive charging of a vehicle battery (1) of a vehicle (2) with a secondary induction device (3) which is designed and / or arranged in such a way that a primary induction device (4), which is supplied by an energy source outside the vehicle (2) is fed and an electromagnetic alternating field (5) is generated in which the secondary induction device (3) can induce an alternating current (6) which supplies a charging device (7) for charging the vehicle battery (1) with energy, with at least one heat transport medium (8) is provided, with the aid of which thermal energy, which arises from the power loss of the primary and / or secondary induction device (3, 4), is at least partially dissipated. According to the invention it is provided that the at least one heat transport means (8) is arranged within or thermally coupled to the primary induction device (4). The invention also relates to a corresponding method.

Description

The invention relates to a device for inductive charging of a vehicle battery.

Induction charging devices are already known from the prior art and are used for contactless charging of a battery in a motor vehicle. An external primary coil is inductively coupled to a secondary coil in the motor vehicle. An alternating current flows through the primary coil, which generates an alternating electromagnetic field around the primary coil. The electromagnetic alternating field induces an alternating current in the secondary coil, which is rectified by the power electronics and fed to the battery.

With the increasing spread of battery-operated electric vehicles, the technology of charging the batteries of such vehicles is becoming increasingly important because parameters of the charging process, in particular the charging speed and the effectiveness of the charging process, are decisive factors for the attractiveness of electric vehicles.

The EP 0 666 805 B1 discloses a method and a device for contactless charging of an electric vehicle via an inductive coupling. A sensor-controlled mechanism moves the primary element of an inductive transmitter close to a secondary element on the underside or at other points of the vehicle. The primary element is positioned by a sensor-controlled motor. A regulation of the charging current with the aid of a battery status detection and a contactless transmission of information between the inverter of the charging station and the battery of the vehicle in both directions is also disclosed. The EP 0 666 805 B1 also describes fast charging with a powerful charger, for example in a parking garage while shopping.

The DE 10 2010 044 999 A1 also shows a charging device for inductive charging of an electrical energy store of a motor vehicle. Thermal energy that arises from power loss in a vehicle-side coil or in a vehicle-side charging device is at least partially used with the help of heat transport means to heat the electrical energy store of the motor vehicle, as long as the temperature of the electrical energy store is below a lower limit temperature.

There are also further proposals in the prior art, in particular to dissipate the heat loss generated at the secondary coil and to make it usable. The disadvantage here is that the heat transport devices are installed and operated in the vehicle and thus lead to a higher weight of the vehicle.

The WO 2011/006884 shows a charging device for inductive charging of an electrical energy store of a motor vehicle. The charging device comprises a primary coil which is designed to induce a voltage in a secondary coil of the motor vehicle for charging the electrical energy store. Feed electronics are arranged below the primary coil in the same housing as the primary coil. Housing fans arranged inside the housing ensure air cooling. Also the DE 10 2015 006 308 A1 describes such an arrangement, which provides a fan device which is arranged in such a way that an air flow that can be generated by means of the fan device flows around power electronics of the charging device and then flows to a lifting mechanism of the primary coil device. Housing fans, however, are particularly susceptible to the effects of the weather, especially when used outdoors for long periods, and require additional installation space.

The present invention is based on the object of specifying a technical teaching for charging a vehicle battery, through the use of which the thermal conditioning of charging devices and batteries of electric vehicles can be improved as far as possible. In particular, this should not lead to significantly higher weights on the vehicle side and should not require any additional mechanical connections between the infrastructure and the vehicle, such as the connection of coolant channels, for example.

This object is achieved by a device and by a method according to one of the independent claims. Advantageous further developments of the invention are the subject of subclaims.

The invention relates to a device for inductively charging a vehicle battery of a vehicle with a secondary induction device, which is designed and / or arranged such that a primary induction device, which is fed by an energy source outside the vehicle and generates an electromagnetic alternating field, in the secondary induction device can induce an alternating current that supplies a charging device for charging the vehicle battery with energy, with at least one heat transport means being provided, with the aid of which heat energy, which arises from the power loss of the primary and / or secondary induction device, is at least partially dissipated. According to the invention it is provided that the at least one heat transport means is arranged within or thermally coupled to the primary induction device.

The primary induction device thus generates an electromagnetic alternating field which induces an alternating current in a secondary induction device which supplies a charging device for charging the vehicle battery with energy. The primary induction device is preferably galvanically connected to an energy source outside the vehicle. Such energy sources are preferably the public power grid or also special power supply devices that are capable of supplying a primary induction device with electrical energy.

The primary induction device will preferably have a plurality of conductor loops through which an alternating current flows, which is provided by the energy source outside the vehicle. The primary induction device preferably does not belong to the vehicle itself, but rather to a device that can be used by a large number of vehicles in a manner similar to a fuel filling station. The primary induction device is preferably designed and / or arranged in such a way that the secondary induction device, which is preferably a component of the vehicle, can be easily brought into a position in which an alternating magnetic field generated by the primary induction device is as effective as possible the secondary induction device can induce an alternating current.

With the aid of this alternating current flowing through the primary induction device, the primary induction device generates the electromagnetic alternating field, which in turn induces an alternating current in the secondary induction device, which supplies a charging device for charging the vehicle battery with energy. The charging device has the task of rectifying the alternating current induced in the secondary induction device so that the resulting rectified voltage can be used to charge the vehicle battery.

The currents flowing in the primary induction device, the secondary induction device and in the charging device are inevitably associated with a power loss, as a result of which a heat loss develops in the primary induction device, the secondary induction device and in the charging device, the energy equivalence of which is external to the energy source of the vehicle, which is not available to the vehicle after the battery has been charged.

The present invention advantageously uses this heat loss, at least in part, by providing heat transport means with the help of which the heat energy, which arises due to power loss primarily in the primary induction device and downstream in the secondary induction device and / or in the charging device, at least partially dissipates and, if necessary, one further use. Such use can be, for example, to heat a vehicle battery, the vehicle interior and / or a component of the air conditioning system of the vehicle. This is achieved on the basis of a targeted arrangement of the primary and secondary induction device and the vehicle battery, for example by thermal coupling via adjacent surfaces of the components, without providing additional mechanical connections such as channels between the components.

According to the invention, the heat transport means which are included in the device do not have any fan devices.

In one embodiment of the device according to the invention, the heat transport means have at least one cooling and / or heating device which has one or more heat transport bodies through which a gaseous and / or liquid heat transport medium flows.

The heat transport means preferably have at least one cooling device which is set up to extract heat from the primary induction device. Examples of such cooling devices are a heat sink through which a preferably gaseous and / or liquid heat transport medium flows and which brings the primary induction device into heat exchange contact with the cooling medium used, preferably via heat conducting means. In order to avoid that undesired currents are induced in the structural elements of the cooling device, which are preferably in good thermal conductivity and are preferably in close spatial contact with the primary induction device, the cooling device is preferably designed in such a way that such undesired (parasitic) alternating currents are induced as far as possible is avoided. For this purpose, it is particularly advantageous to avoid closed loops made of electrically conductive material when constructing the cooling device as far as possible.

In addition, it is advantageous in this context to interrupt electrically conductive and thermally conductive areas of the cooling device, preferably at least in part, with electrically insulating and preferably highly thermally conductive construction elements, so that in these otherwise electrically conductive construction areas the Cooling device no undesired currents can be induced. For this purpose, heat-conducting foils or other heat-conducting but electrically insulating materials are preferably used. Such materials preferably consist of electrically insulating substances, in which metallic grains or threads are preferably arranged finely distributed in such a way that there is no electrically conductive connection, but that the heat conduction properties of these metallic grains, wires or threads cause these structural elements to conduct heat sufficiently well . For this purpose, bodies made of silicon or zinc oxide are preferably used, into which particles, threads or wires made of aluminum, copper or also silver are embedded. Fillers made from carbon nanoparticles are also preferably used to improve thermal conductivity. Elastic bodies are preferred here because they are suitable for reducing or absorbing mechanical stresses that can be built up in the structures of the heat sinks by temperature gradients or by temperatures that change over time.

Thermally conductive pastes or thermally conductive adhesives are also preferably used at the transitions between the cooling device or the heat-conducting means and the primary induction devices to be cooled. These thermally conductive pastes or thermally conductive adhesives preferably have good heat conduction properties in conjunction with electrically insulating properties.

The heat transport means preferably also have at least one heating device, which is set up to at least partially dissipate heat extracted from the primary induction device, to cool it and to use the cooling or heat for other components of the inductive charge such as supply lines and contacts of the primary induction device .

In one embodiment of the invention, the cooling and / or heating device has meandering heat transport bodies.

As a result, a very good efficiency is achieved by increasing the contact area between the heat transfer bodies and the conductor loops. This is a preferred variant, since such an arrangement of the component in the primary induction device can be produced inexpensively, for example by means of bonding processes.

In one embodiment of the invention, the cooling and / or heating device is arranged within the primary induction device in such a way that it is provided below and / or in the spaces between the conductor loops of the primary induction device.

This ensures that the heat loss is dissipated immediately, since in this way the cooling channels are positioned in the immediate vicinity of the conductor loops. This can take place as a parallel branch of the main cooling channel or also through a separate branch.

In one embodiment of the invention, the heat transport means are provided in an additional contacting plate that can be arranged between the primary induction device and the secondary induction device outside the vehicle.

In this embodiment, an additional contacting plate is provided that can dissipate the heat generated by the primary and secondary induction devices. Due to the arrangement between the induction devices but outside the vehicle, there is no need for an additional mechanical or automated connection. The contacting plate can be arranged on the primary induction device via a thermal coupling, preferably over the area, particularly preferably over the entire area. In use, this arrangement can then be brought up to contact with the secondary induction device attached to the underside of the vehicle, for example by means of a lifting device. Here, too, means can be provided which further improve the thermal coupling between the contacting plate and the secondary induction device.

As described above with regard to the heat transport means of the induction devices, cooling or heating devices can be provided within the contacting plate either alone instead of the heat transport means in the primary induction device or in addition thereto. This configuration is particularly advantageous in both alternatives because simultaneous thermal contact of both the primary and the secondary induction device with the heat transport means can be established.

In one embodiment of the invention, the contacting plate has iron webs which are arranged in such a way that the magnetic flux generated by the primary induction device is divided between the individual iron webs and is then guided to the primary induction device.

In this way, the magnetic flux of the field generated by the conductor loops of the primary induction device can be transmitted in a targeted and low-loss manner to the conductor loops of the secondary induction device. Simultaneously the iron webs serve the mechanical stability of the contacting plate and the mechanical protection of the heat transport means provided within the contacting plate.

In one embodiment of the invention, the primary induction device and / or the secondary induction device and / or the additional contacting plate have at least some sections of the spaces between the conductor loops or the iron webs filled with a thermally conductive potting compound.

Examples of thermally conductive potting compounds are ceramic-filled two-component silicone elastomers, thermally conductive polyurethanes or filled epoxy resins.

In one embodiment of the invention, the secondary induction device is arranged in the area of the vehicle floor, preferably in the area of the middle vehicle floor between the axles of the vehicle.

In the case of an electric vehicle, it will often be desirable to arrange the secondary induction device in the vicinity of the outer boundary of the vehicle in order to allow the vehicle to dock easily with the charging station during the charging process, in which the secondary induction device comes into a position relative to the primary induction device that enables effective induction. The vehicle battery is often attached in the middle of the lower vehicle area in order to be able to protect it particularly effectively against harmful mechanical effects, in particular in the event of traffic accidents.

In one embodiment of the invention, the vehicle battery is arranged in thermal coupling with the secondary induction device, preferably above the secondary induction device.

According to the invention, a preferred arrangement of the primary and secondary induction devices and the vehicle battery therefore provides that there is a flat, preferably full-area, thermal contacting of the components. This can be done, for example, by direct contact with the outer surfaces of the components or by providing thermally conductive intermediate layers. Such a thermally conductive intermediate layer thus comprises a heat conduction device. This heat-conducting device preferably comprises at least one Peltier element, the warm side of which is brought into heat-conducting contact with a heat sink or the heat-conducting device in this operating mode of the arrangement according to the invention. This is done during the charging process, preferably by docking the Peltier element on the heat sink or the heat conduction device, which is arranged in close proximity to the primary induction device in such a way that when the vehicle is docked on the primary induction device, there is automatically a thermally conductive contact of the Peltier element comes with the heat sink or the heat conduction device.

In other words, the device according to the invention for charging a vehicle battery is based on the idea that through an arrangement of the primary induction device, the secondary induction device and possibly also the vehicle battery as described above, heat loss can be dissipated by cooling the primary in a targeted and simple manner without further mechanical connections Induction device can be done. The cooling is arranged either inside the primary induction device in the form of cooling devices through which fluid flows, such as cooling channels and / or outside the primary induction device in the form of an additional contacting plate.

In this way, cooling devices on or in the secondary, i.e. on-board, induction device can advantageously be avoided. In addition to a weight reduction, this can also prevent damage or failure of the vehicle from permanent mechanical stress due to leaks or breaks in the thermal coupling of the secondary induction device, the charging device and the vehicle battery.

The vehicle battery preferably has a housing with heat-insulating walls. According to the invention, only the bottom of the vehicle battery enables thermal coupling with the secondary induction device arranged below. In this way it is achieved that the heat given off by the secondary induction device can be effectively fed to the vehicle battery, because the heat is largely prevented from escaping through the walls of the vehicle battery housing.

The invention further comprises a method for charging a vehicle battery of a vehicle, in which a primary induction device, which is fed by an energy source outside the vehicle and generates an alternating electromagnetic field, which induces an alternating current in a secondary induction device, which a charging device for charging the vehicle battery supplied with energy, the thermal energy generated by the power dissipation in the secondary induction device in the primary Induction device and / or arises in the charging device, with the aid of heat transport means provided for this purpose, is at least partially removed. According to the invention it is provided that at least one heat transport means is arranged within or thermally coupled to the primary induction device and absorbs the thermal energy there.

According to the invention it is provided that the heat is not transported by means of fan devices.

In one embodiment of the method according to the invention, the vehicle battery is connected to the secondary induction device in such a way that it is heated or cooled by the heat transport means.

• 1 in einer stark schematisierten Darstellung eine Querschnittsansicht einer beispielhaften Vorrichtung gemäß der vorliegenden Erfindung, und
• 2 in einer stark schematisierten Darstellung eine perspektivische Querschnittsansicht einer beispielhaften Ausgestaltung einer Kontaktierungsplatte gemäß der vorliegenden Erfindung.

There are a large number of possibilities for designing and developing the device and the method for charging a vehicle battery. For this purpose, reference may first be made to the claims subordinate to claim 1. In the following, an embodiment of the invention may be explained in more detail with reference to the drawings and the associated descriptions. In the drawings shows:

• 1 in a highly schematic illustration a cross-sectional view of an exemplary device according to the present invention, and
• 2 in a highly schematic representation, a perspective cross-sectional view of an exemplary embodiment of a contacting plate according to the present invention.

The figures serve the conceptual illustration and are neither in their dimensions nor in their proportions to scale.

1 shows schematically the basic structure of a device for charging a vehicle battery 1 of a vehicle 2 . The vehicle 2 is preferably a land-based, partially or fully electrically operated motor vehicle.

The device according to the invention comprises a secondary induction device 3rd , which is designed and arranged in the vehicle floor that a primary induction device 4th coming from an energy source outside the vehicle 2 is fed, an alternating electromagnetic field 5 generated.

One in the 1 not shown outside the vehicle 2 arranged energy source provides the energy that is required so that the preferably outside of the vehicle 2 arranged primary induction device 4th an alternating magnetic field 5 can generate, which in the preferably in the vehicle 2 arranged secondary induction device 3rd an alternating current 5 induced. This in the secondary induction device 3rd induced alternating current 5 is used by the preferably in the vehicle 2 arranged charging device rectified and preferably reshaped so that it is used to charge the vehicle battery 1 can be used.

In the secondary induction device 3rd thus becomes an alternating current 6th induces a charging device for charging the vehicle battery 1 supplied with energy. In addition, there is at least one heat transport medium 8th provided, with the help of which thermal energy generated by the power dissipation of the primary and / or secondary induction device 3rd , 4th arises, is at least partially discharged. According to the invention, at least one heat transport means can be thermally coupled to the primary induction device 4th arranged.

In the embodiment shown, the heat transport means are cooling tubes 9 preferably meandering in one between the primary induction device 4th and the secondary induction device 3rd additional contacting plate arranged outside the vehicle 10 intended. The cooling pipes 9 are traversed by a fluid medium and serve to transport heat to the outside and / or to another point of use.

The contacting plate 10 has iron webs in its core 11 which are arranged and shaped such that they are of the primary induction device 4th Magnetic field to the charging coils with little loss and very efficiently 6th the secondary induction device 3rd conduct.

The thermal coupling of the arrangement of the primary induction device 4th , Contacting plate 10 and secondary induction plate 3rd can be produced by moving the components up to the flat system. It is equally possible to provide an additional heat-conducting film or similar intermediate layers in order to further improve the heat conduction between the components.

In the embodiment shown, the invention is also inside the vehicle 2 the vehicle battery 1 directly above the secondary induction device 3rd arranged. Here, too, a thermal coupling can preferably be established through corresponding thermally conductive components in the housings of the battery and the secondary induction device, through which an indirect thermal connection of the battery as well 1 to the cooling of the contacting plate 10 is made possible.

In 2 is a schematic perspective cross-sectional view of a detail of a contacting plate 10 shown. Inside the contacting plate 10 Iron bars are evenly spaced apart so that the magnetic field generated by the primary induction device is applied to the individual bars 11 divided and then led with a low magnetic resistance to the conductor loops of the secondary induction device. In the cavities between the iron bars 11 are meandering cooling channels 9 provided through media inlets and outlets 13th , 14th can be supplied with a cooling fluid. On the flat outer sides of the contacting plate 12th that produce thermal contact with the primary and secondary induction device in the installed or in-use position, is also a thermal coupling 12th , for example in the form of heat-conducting foils, are provided.

List of reference symbols

1

Vehicle battery

2

vehicle

3

secondary induction device

4th

primary induction device

5

alternating electromagnetic field

6th

Alternating current

7th

Charging device

8th

Means of heat transfer

9

Cooling and / or heating device

10

Contacting plate

11

Iron bars

12th

Thermal coupling agents

13th

Coolant inlet / outlet

14th

Coolant inlet / outlet

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 0666805 B1 [0004]
• DE 102010044999 A1 [0005]
• WO 2011/006884 [0007]
• DE 102015006308 A1 [0007]

Claims (11)

Device for inductive charging of a vehicle battery (1) of a vehicle (2) with a secondary induction device (3) which is designed and / or arranged in such a way that a primary induction device (4) fed by an energy source outside the vehicle (2) and an alternating electromagnetic field (5) is generated in which the secondary induction device (3) can induce an alternating current (6) which supplies a charging device (7) for charging the vehicle battery (1) with energy, at least one heat transport means (8) being provided is, with the help of which heat energy, which arises from the power loss of the primary and / or secondary induction device (3, 4), is at least partially dissipated, characterized in that the at least one heat transport means (8) is inside or can be thermally coupled to the primary induction device ( 4) is arranged. Device according to Claim 1 wherein the heat transport means (8) have at least one cooling and / or heating device (9) which has one or more heat transport bodies through which a gaseous and / or liquid heat transport medium flows. Device according to Claim 2 , wherein the cooling and / or heating device (9) has meandering heat transport bodies. Device according to Claim 2 or 3rd , wherein the cooling and / or heating device (9) is arranged within the primary induction device (4) in such a way that it is provided below and / or in the spaces between the conductor loops of the primary induction device (4). Device according to one of the Claims 1 to 4th wherein the heat transport means (8) are provided in an additional contacting plate (10) which can be arranged between the primary induction device (4) and the secondary induction device (3) outside the vehicle (2). Device according to one of the preceding claims, wherein the contacting plate (10) has iron webs (11) which are arranged such that the magnetic flux generated by the primary induction device (4) is divided between the individual iron webs (11) and then to the primary induction device (3) is performed. Device according to one of the preceding claims, wherein the primary induction device (4) and / or the secondary induction device (3) and / or the additional contacting plate (10) at least partially fill the gaps between the conductor loops or the iron webs (11) with a thermal Have conductive potting compound. Device according to one of the preceding claims, wherein the secondary induction device (3) is arranged in the area of the vehicle floor, preferably in the area of the middle vehicle floor between the axles of the vehicle. Device according to one of the preceding claims, wherein the vehicle battery (1) is arranged in thermal coupling with the secondary induction device (3), preferably above the secondary induction device (3). Method for charging a vehicle battery (1) of a vehicle (2), in which a primary induction device (4), which is fed by an energy source outside the vehicle (2) and generates an alternating electromagnetic field (5), which is generated in a secondary induction device ( 3) induces an alternating current which supplies a charging device (7) for charging the vehicle battery (1) with energy, the thermal energy generated by the power loss in the secondary induction device (3), in the primary induction device (4) and / or in the charging device (7) arises, is at least partially discharged with the help of heat transport means (8) provided for this purpose, characterized in that at least one heat transport means (8) is arranged within or thermally coupled to the primary induction device (4) and absorbs the heat energy there. Procedure according to Claim 10 , wherein the vehicle battery (1) is connected to the secondary induction device (3) in such a way that it is heated or cooled by the heat transport means (8).

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