Inductive charging device for a vehicle charging system

Abstract

The invention relates to an inductive charging device for a vehicle charging system, comprising an energy transmission winding, at least one flux guiding element, at least one first sensor winding, and a second sensor winding. The flux guiding element is suitable for conducting a magnetic field during an energy transmission which is carried out between an additional inductive charging device and the energy transmission winding, and the first sensor winding and the second sensor winding are arranged about at least one of the at least one flux guiding elements.

Description

[0001] Inductive charging device for a vehicle charging system

[0002] The invention relates to an inductive charging device for a vehicle charging system according to the preamble of the independent patent claim.

[0003] DE 10 2014 202 747 A1 discloses a double-winding system used to determine a positional deviation between a primary coil and a secondary coil of an inductive charging system. The two windings of the double-winding system are offset from each other by a specific angle and wound around a common ferrite element. The magnetic field of the primary coil induces a voltage in the two windings. The two voltages are evaluated by an evaluation unit, and a positional deviation between the primary coil and the secondary coil is calculated from this. For this purpose, the double-winding system requires the installation of an additional component with its own ferrite element. Furthermore, it is not possible to position the double-winding system in such a way that no or only very low voltages are induced during the charging process.

[0004] The present invention is concerned with the object of providing improved or at least alternative embodiments for an inductive charging device of the type mentioned above, in particular those which reduce the complexity and increase the longevity of the components used.

[0005] Being able to charge vehicles inductively offers a number of advantages over conventional conductive charging. First and foremost, the increased convenience is worth mentioning, as it eliminates the need to handle sometimes very heavy charging cables and plugs. However, for inductive charging, it is important that the vehicle's inductive charging device is positioned as precisely as possible in relation to the stationary, e.g., floor-mounted inductive charging device. This is difficult if the vehicle is positioned purely manually over the stationary inductive charging device, and the driver requires support from an assistance system that either provides them with information about a positional deviation between the mobile inductive charging device in the vehicle and the stationary inductive charging device, or from an automated positioning system that directly takes over the parking process automatically.A sensor system capable of detecting a corresponding positional deviation is required. It is advantageous if no initial calibration is required between the stationary inductive charging device and the mobile inductive charging device in the vehicle. Furthermore, the positioning system should have the greatest possible range. This means that the positioning system should be able to precisely determine a positional deviation even at the greatest possible distance between a stationary inductive charging device and a mobile inductive charging device in the vehicle.

[0006] The device according to the invention with the features of the independent patent claim has the advantage over the prior art that sensor windings are integrated into the inductive charging device, no additional magnetic core or flux guide element is required, and the inventive arrangement of the sensor windings allows the voltages induced in the sensor windings during the charging process to be reduced to a minimum. Furthermore, the proposed arrangement also enables the sensor windings to be accommodated in the inductive charging device in the vehicle, which is usually delimited by a housing. No additional cabling is necessary, as would be the case with an arrangement outside the inductive charging device in the vehicle. Further important features and advantages of the invention emerge from the subclaims, from the drawings, and from the associated description of the figures with reference to the drawings.

[0007] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0008] The present invention proposes an inductive charging device for a vehicle charging system, comprising an energy transmission winding and at least one flux guiding element and at least one first sensor winding and a second sensor winding, having the following features: the flux guiding element is suitable for guiding a magnetic field during an energy transmission which takes place between a further inductive charging device and the energy transmission winding, the first sensor winding is arranged around at least one of the at least one flux guiding elements, and the second sensor winding is arranged around at least one of the at least one flux guiding elements.

[0009] Inductive charging involves transferring energy in the form of a magnetic field between two inductive charging devices, usually between a stationary charging device and a mobile inductive charging device.

[0010] The term "inductive charging device" therefore refers to only one of at least two components required for energy transfer during an inductive charging process. During an inductive charging process, a power transfer coil in an inductive charging device generates an alternating magnetic field. This alternating magnetic field induces a voltage in another power transfer coil of another inductive charging device. This additional inductive charging device thus serves as a counterpart for this specific charging process. The energy is transferred wirelessly and absorbed by induction of a voltage.

[0011] Inductive charging devices can be used for inductive charging of vehicles. In principle, an inductive charging device according to the invention can be used for any type of land, water, or aircraft with an electric or hybrid drive. This applies in particular to passenger cars, buses, and trucks.

[0012] A vehicle charging system comprises at least one mobile inductive charging device and another, usually stationary, inductive charging device. A mobile inductive charging device can, for example, be mounted on and / or in a vehicle.

[0013] An inductive charging device on and / or in the vehicle is therefore suitable for absorbing the magnetic field and making electrical energy available from an energy storage device in the vehicle, for example a battery or accumulator in the vehicle.

[0014] In principle, a vehicle charging system can also be used for bidirectional charging. This allows the vehicle to temporarily feed energy from the energy storage system into the power grid via the vehicle charging system.

[0015] An inductive charging device has a power transmission coil that can efficiently receive and / or emit a magnetic field from another power transmission coil during the charging process. Preferably, power levels of 3 kW to 500 kW can be transmitted, particularly preferably 3 kW to 50 kW.

[0016] In general, a coil is defined here as a component for generating or receiving a magnetic field. A coil can consist of a winding and optionally other elements such as a magnetic core and a coil carrier. A winding is a wound arrangement of a current conductor. A winding can consist of one or more turns, with one turn representing one full circuit of a conductor. In general, however, a winding can also consist of fewer than one turn, for example, 0.5 turns. Of course, a partial number of turns, such as 2.5 turns, is also possible.

[0017] An energy transmission winding can be designed in various forms and can consist, for example, of a high-frequency stranded wire with a diameter between 0.5 mm and 10 mm, preferably made of copper.

[0018] The sensor windings are required for the positioning process. If the vehicle is still some distance away from the stationary inductive charging device, for example between 5 and 10 m, the stationary inductive charging device can emit a signal, preferably a magnetic field, which induces a voltage in the sensor windings. By comparing the voltages and correspondingly evaluating them, a positional deviation between the vehicle and the stationary inductive charging device can be determined. In principle, it is also possible for the mobile inductive charging device to emit the signal and the stationary inductive charging device to receive it. A sensor winding according to the invention can be designed in different forms and can have half, one, or preferably several turns. Of course, an incomplete number of turns, such as 2.5 turns, is also possible.A conductor of such a sensor winding can, for example, have a cross-sectional area between 0.01 and 2 mm. 2 A conductor can be implemented as a stranded wire, as a single conductor, or in another form, for example, in the form of a circuit board. In a conductor structure implemented on a circuit board, the conductor tracks can have cross-sections of, for example, the order of 0.8 pm by 35 pm.

[0019] A flux guide element is designed to guide a magnetic field in a predetermined manner. It has a high magnetic permeability with p r >1 , preferably p r >50, especially preferred p r>100. The flux guide element represents a magnetic core for the energy transmission winding. In particular, the high permeability influences the magnetic field in such a way that the greatest possible magnetic flux is transferred to the energy transmission winding. With a flux guide element, the energy transmission winding absorbs a greater magnetic flux than without a flux guide element, all other parameters being equal. A flux guide element can be made of a ferromagnetic or, preferably, a ferrimagnetic material, particularly preferably a ferrite. A flux guide element can preferably be plate-like—in the form of a planar core—and can be arranged in the inductive charging device on the side of the energy transmission winding facing away from the opposite side, i.e., the other inductive charging device.

[0020] By arranging the first sensor winding and the second sensor winding around at least one of the at least one flux guide elements, the at least one of the at least one flux guide elements performs a dual function. It acts as a magnetic core for both the first sensor winding and / or the second sensor winding, as well as a magnetic core or flux guide element for the energy transmission winding. Thus, no separate flux guide element is required for the sensor winding, which leads to simplified manufacturing.

[0021] The arrangement of a sensor winding around a flux guide element here means that at least a portion of the flux guide element is enclosed by a sensor winding. The first sensor winding and the second sensor winding can be arranged around the same flux guide element or around two different flux guide elements, or even around multiple flux guide elements.

[0022] The two sensor windings can either be arranged only around one or more flux guiding elements or also around further elements, such as the energy transmission winding and / or a cooling and / or a shielding device.

[0023] An inductive charging device according to the invention is preferably a mobile inductive charging device which is arranged on and / or in a vehicle or a stationary inductive charging device.

[0024] A stationary inductive charging device is the non-mobile part of a vehicle charging system, i.e. the part that does not move with the vehicle.

[0025] A stationary inductive charging device can preferably be located on, at, or in a floor. This can be an inductive charging device mounted on the ground or an inductive charging device sunk into a subsurface or into the ground. A floor can be a roadway, a parking lot surface, a garage floor, a floor in a parking garage, or another building. However, a stationary inductive charging device can also be located on walls or similar structures.

[0026] It is also possible to use a stationary inductive charging device for a dynamic inductive charging process. With a dynamic inductive charging process, a vehicle's energy storage device can be charged while the vehicle is moving. For example, in this case, the stationary inductive charging device can extend along the roadway, under, in, or on the road surface.

[0027] A mobile inductive charging device can be arranged on and / or in a vehicle. This generally refers to the part of a vehicle charging system that moves with the vehicle. Preferably, the first sensor winding has a first radial longitudinal direction and the second sensor winding has a second radial longitudinal direction. The first radial longitudinal direction and the second radial longitudinal direction are each arranged at an angle of 45° + / - 10°, preferably at an angle of 45°, to the longitudinal direction of the vehicle. The first radial longitudinal direction and the second radial longitudinal direction intersect at an angle of 70°-110°, preferably perpendicularly.

[0028] In general, a winding extends in at least two dimensions around an axis. The main extension direction perpendicular to the winding axis is referred to here as the radial longitudinal direction. Thus, for a winding with a rectangular, non-square cross-section, the main extension direction runs along or parallel to the longer side of the rectangle. For a winding with an elliptical cross-section, the radial longitudinal direction runs along or parallel to the main axis of the ellipse. The radial longitudinal direction of a sensor winding according to the invention can preferably lie in a plane that extends parallel to the ground.

[0029] A corresponding arrangement of the angles of the radial longitudinal directions is advantageous for the highest possible sensitivity in detection and the simplest possible calculation of the position deviation between the vehicle and the stationary inductive charging device.

[0030] If the two angles between the respective radial longitudinal direction of the sensor windings and the longitudinal direction of the vehicle are approximately equal, this means that the sensor windings are arranged symmetrically to the direction of travel.

[0031] When the term “longitudinal direction of the vehicle” is used in relation to a stationary inductive charging device, it refers to the “longitudinal direction of the vehicle” to be achieved when the positioning process is successfully completed, i.e. the “longitudinal direction of the vehicle” as it is positioned during the energy transfer process.

[0032] This is particularly advantageous because the sensor windings are specifically designed to detect a right-left positional deviation between the inductive charging device in the vehicle and the stationary inductive charging device. Due to the symmetrical arrangement of the sensor windings with respect to the direction of travel, the voltages induced in the sensor windings are also symmetrical for equally large positional deviations to the right or left, thus enabling a relatively simple calculation of the positional deviations from the induced voltages. If the two angles are 45°, the two sensor windings are at a 90° angle to each other, which is ideal for optimal evaluation of the sensor signals.

[0033] It is preferred that the first sensor winding has a first radial longitudinal direction and the second sensor winding has a second radial longitudinal direction and the first radial longitudinal direction and the second radial longitudinal direction intersect in the region of the area spanned by the energy transmission winding.

[0034] The area spanned by the power transmission winding refers to the area spanned by the power transmission winding in the plane perpendicular to its winding axis. This explicitly includes the inner area of ​​the power transmission winding, where no winding is present, but not the area located outside the power transmission winding.

[0035] It's important to note that "direction," such as "radial longitudinal direction," always refers to a straight line and not a distance defined by the beginning and end of the component. The fact that the two radial longitudinal directions of the sensor windings intersect within the area spanned by the power transmission winding does not necessarily mean that the sensor windings themselves intersect; it's also possible that they would only intersect in the extension.

[0036] Arranging the two sensor windings so that the two radial longitudinal directions intersect in the area spanned by the energy transfer winding offers advantages for the evaluation of the two sensor signals. When a signal is sent from the stationary inductive charging device for positioning, a voltage is induced in each of the two windings. The ratio of the two voltages allows direct conclusions to be drawn about the positional deviation between the vehicle and the stationary inductive charging device. It is particularly advantageous if the two sensor windings are arranged symmetrically with respect to the longitudinal direction of the vehicle.

[0037] It is particularly preferred that the first radial longitudinal direction and the second radial longitudinal direction intersect at least approximately in the center of the energy transmission winding.

[0038] The center of the power transmission winding refers to the area a few centimeters around the geometric center of the power transmission winding in the plane perpendicular to the winding axis of the power transmission winding. "Center" here refers only to the two dimensions in which the power transmission winding primarily extends, for example, the driving plane. The intersection does not have to be centrally located in the power transmission winding in the direction in which the power transfer takes place; for example, a central location does not occur in relation to the height of the vehicle.

[0039] This is advantageous because the two radial longitudinal directions of the two sensor windings are tilted to the longitudinal direction of the vehicle by an angle that is advantageous for optimal detection of a positional deviation between the vehicle and the stationary inductive charging device.

[0040] In addition, the sensor windings are arranged in relation to the energy transmission winding in such a way that the lowest possible voltages are induced in the sensor windings during the energy transmission process.

[0041] In one embodiment, the two sensor windings intersect at least approximately in the center of the energy transfer winding. The fact that only the radial longitudinal directions of the two sensor windings intersect approximately in the center of the energy transfer winding is a weaker condition. In this case, it is also possible for the two sensor windings to be relatively short and arranged in a "V" shape. If these two sensor windings are notionally extended in their radial longitudinal direction, these radial longitudinal directions intersect, but not the two sensor windings themselves. The fact that the two sensor windings themselves intersect is a stricter condition. In this case, the sensor windings are longer than in a "V"-shaped arrangement and actually intersect. The arrangement is "X"-shaped.In this embodiment, the sensor windings have a larger area in which voltage is induced than in embodiments where only the radial longitudinal directions of the sensor windings intersect in the extension, and more voltage can be induced. In this case, an actual crossing of the sensor windings occurs, rather than merely a crossing in the extension of the sensor windings.

[0042] It is advantageous if, in this embodiment, the two sensor windings are arranged point-symmetrically to the center of the energy transmission winding.

[0043] In an alternative preferred embodiment, the inductive

[0044] Charging device has at least four sensor windings, two of which are arranged on opposite sides of the center of the energy transmission winding and all radial longitudinal directions run approximately through the center of the energy transmission winding and / or the four radial longitudinal directions of the four sensor windings each form an angle of 45° + / - 10°, preferably 45°, with the longitudinal direction of the vehicle.

[0045] Thus, the four sensor windings are arranged like a cross around the center of the energy transmission winding, whereby the center of the energy transmission winding itself is free of a sensor winding.

[0046] Preferably, the four sensor windings can be arranged radially at equal intervals around the center of the energy transmission winding and can be arranged at approximately the same angle to one another. For example, the angle between the respective radial longitudinal direction of a sensor winding and the radial longitudinal direction of the adjacent sensor winding can always be 45° + / - 10°, preferably 45°.

[0047] This embodiment is advantageous over the embodiment with only two sensor windings, as this arrangement allows for more efficient use of the installation space and allows for more windings per sensor winding. Overall, more voltage is induced. Compared to the embodiment with two intersecting sensor windings, it also offers the advantage that the center of the energy transmission winding remains free of a sensor winding, allowing stabilizing elements to be incorporated in this area.

[0048] The four sensor windings can be interconnected, preferably in series. Particularly preferably, the two diagonally opposite sensor windings are connected in series. It is advantageous that the first radial longitudinal direction and the second radial longitudinal direction are at least approximately parallel to the main direction of the magnetic field lines that form during energy transfer in the flux guide element in the area covered by the sensor winding.

[0049] The main direction of the magnetic field lines at each location refers to the direction in which the magnetic field lines primarily extend in the flux guide element. This does not represent the exact path of the magnetic field lines through the sensor winding; rather, the radial longitudinal directions are intended to be oriented according to the path of the magnetic field lines in the region of the sensor winding. During energy transfer from the stationary inductive charging device to the inductive charging device in the vehicle, the magnetic field is guided in one or more flux guide elements. If one or more flux guide elements are plate-shaped, a magnetic field with magnetic field lines that run approximately radially with respect to the energy transfer winding is established in the flux guide elements during the charging process.Although a voltage is to be induced in the sensor windings during the positioning process in order to calculate a positional deviation between the vehicle and the stationary inductive charging device, the magnetic fields are significantly higher during the charging process and it is therefore important that as little voltage as possible is induced in the sensor windings to avoid damaging them or neighboring components. The field component perpendicular to the radial longitudinal direction of the sensor windings is relevant for the induced voltage. If a sensor winding is arranged in a way that ensures that the radial longitudinal direction of the sensor winding is at least approximately parallel to the main direction of the magnetic field lines in the flux guide elements during the charging process, no or only a low voltage is induced in the sensor winding.

[0050] Alternatively, it is also possible for the first radial longitudinal direction and the second radial longitudinal direction to intersect outside the center of the energy transmission winding.

[0051] Preferably, the energy transmission winding is designed as a flat coil and / or the first sensor winding and the second sensor winding as a solenoid. A flat coil can be a spiral flat coil, in particular a circular spiral flat coil or a rectangular spiral flat coil. A spiral flat coil can be wound in the form of an Archimedean spiral. The winding shape can be circular (circular spiral flat coil), but other shapes are also possible, such as square or rectangular, or even similar to a rectangle with rounded corners (rectangular spiral flat coil). The spiral lies in a plane. A flat coil is particularly suitable for transmitting the highest possible power between a stationary inductive charging device and an inductive charging device in the vehicle.

[0052] A solenoid is also called a cylindrical coil or solenoid coil. A solenoid can be wound in the shape of a helix or a cylindrical spiral. However, the winding shape does not have to be circular, but can also have other shapes, such as square or rectangular, or even similar to a rectangle with rounded corners. The important difference to a flat coil is that the windings are not in one plane, but extend along an axis. However, two or more windings can also run parallel and thus be in the same plane perpendicular to the axis. The shape of the solenoid is well suited to detecting a signal sent by the stationary inductive charging device during the positioning process.

[0053] In a further preferred embodiment, a plurality of flux guide elements are arranged radially around the center of the energy transmission winding, with gaps between the flux guide elements also extending radially.

[0054] From a manufacturing perspective, it is either impossible or very difficult to produce a large flux guide element that covers the entire surface of the energy transfer coil or even extends beyond it. Therefore, several smaller flux guide elements must usually be placed next to one another. For this purpose, rectangular flux guide elements can be used. These are easier to manufacture. Smaller gaps are then always present between the flux guide elements. These can negatively influence the guidance of the magnetic field. With rectangular flux guide elements, the gaps between the flux guide elements will always run partially perpendicular to the magnetic field lines. Therefore, it is advantageous if the gaps between the flux guide elements also run radially, thus minimizing the impact on the guidance of the magnetic field.

[0055] Preferably, the first sensor winding and the second sensor winding are formed by conductor tracks which are applied to at least one printed circuit board, preferably to at least two printed circuit boards, in particular to at least one upper printed circuit board and at least one lower printed circuit board.

[0056] Here, the turns of a sensor winding are realized in the form of conductor tracks on printed circuit boards.

[0057] The conductor tracks can be made of copper, for example.

[0058] The conductor tracks can be multi-layered, preferably double-layered. The cross-section of such a conductor track can be adapted much more flexibly to the constraints imposed by the limited installation space. In particular, it is possible to design the cross-section of the conductor tracks as a rectangle with a low height, with the height in this case being perpendicular to the substrate.

[0059] Implementing a sensor winding using conductor tracks on printed circuit boards makes it possible to significantly reduce the height of the sensor winding compared to conventional windings, such as those based on high-frequency stranded conductors. This type of sensor winding therefore requires less installation space, particularly in the dimension along the winding axis of the power transmission winding, which is the most critical in terms of installation space. The manufacturing process for a sensor winding based on printed circuit boards is also simpler compared to conventional sensor windings with wound high-frequency stranded conductors.

[0060] It is preferred that the energy transmission winding is thermally connected to one of the at least one flux guiding elements and that the at least one flux guiding element is thermally connected to a cooling device, preferably to a cooling plate and / or to a metallic shield.

[0061] The fact that one component is thermally connected to another means that these two components are either directly connected to one another, i.e. they touch one another directly, or are connected to one another via solid bodies with good thermal conductivity. Between the two components there can be one or more layers or other solid bodies, such as thermally conductive intermediate layers, a thermal interface material (TIM), metal bodies or sheets, adhesives with good thermal conductivity, etc. In particular, the thermal conductivity between the two components should preferably be in the range of 0.1 - 1.0 K / W. In order to dissipate waste heat generated by the various components of an inductive charging device, a cooling device, preferably a cooling plate, can be used. A fluid can flow through such a cooling plate and it can transfer absorbed waste heat to this fluid.Alternatively, a cooling plate can be solid and also release the absorbed waste heat into the ambient air, for example through cooling fins and / or a heat exchanger.

[0062] The cooling plate can be made of metal, particularly aluminum.

[0063] Inductive charging generates strong magnetic and electromagnetic fields. To prevent these fields from interfering with or destroying electrical components in the vehicle, or causing damage through heating, they must be shielded. A metallic shield can be used for this purpose.

[0064] A metal sheet, such as aluminum, can be used as the metallic shield. However, it is also possible to make the shield slightly thicker, as a shielding plate.

[0065] The metallic shield can also serve as a cooling plate. The slightly thicker shielding plate version is more suitable for this purpose.

[0066] It is important that the components to be cooled are thermally well connected to the cooling plate.

[0067] Thermally bonded means that the components mentioned are in thermal contact, i.e. a thermal exchange between them is possible via a connection that conducts heat as well as possible.

[0068] The thermal path leads from the energy transfer winding via the at least one flux guide element to the cooling plate. This allows the waste heat from the energy transfer winding and the at least one flux guide element to be dissipated to the cooling plate. Since the sensor windings can be arranged in regions around the at least one flux guide element, it is important that these sensor windings interfere with the thermal path as little as possible. To achieve this, it is particularly important to keep the area of ​​thermally insulating circuit board material as small as possible when implementing the sensor winding on circuit boards.

[0069] In general, the cooling device does not have to be designed as a cooling plate, but can be any body used for active or passive cooling.

[0070] In a preferred variant, at least one of the at least one printed circuit boards has a smaller width in a longitudinal region of the printed circuit board than in a contact region of the printed circuit board.

[0071] Here, the longitudinal area of ​​a circuit board is the area that runs along the radial longitudinal direction of the sensor winding. The contact area of ​​the circuit boards is located at both ends of the longitudinal area of ​​the circuit boards. Here, it is possible to connect the conductor tracks of different circuit boards to each other.

[0072] The width does not have to be reduced across the entire length. It can also be reduced only in certain sections, or only certain areas along the width are left out. The key to this variant is that PCB material is saved by not using the entire width of the PCBs along the length.

[0073] This shape minimizes the amount of insulating circuit board material. Since the insulating circuit board material also has poor thermal conductivity, this optimized shape allows for more waste heat to be dissipated from the various components of the inductive charging device. Furthermore, it is possible for only one of the two contact areas to be wider than the longitudinal area, while the other contact area can be the same width as the longitudinal area or even taper towards the end.

[0074] In a preferred embodiment, the first sensor winding and the second sensor winding consist of upper conductive tracks on an upper circuit board and lower conductive tracks on a lower circuit board.

[0075] The conductor tracks on the upper circuit board can be connected to the conductor tracks on the lower circuit board to create a spiral winding.

[0076] The upper conductor track can be arranged predominantly above one or more flux guiding elements and the lower conductor track can be arranged predominantly below one or more flux guiding elements.

[0077] The terms "above" and "below" or "upper" and "lower" refer to the arrangement of an inductive charging device that extends primarily parallel to the ground. If, for example, a charging device is arranged parallel to a wall, the terms continue to be understood as "on one side of the flux guide elements" and "on the other side of the flux guide elements," without departing from the scope of the invention.

[0078] In one variant, the upper conductor tracks are soldered to the lower conductor tracks.

[0079] Preferably, the upper conductor tracks are connected to the lower conductor tracks via through-plated and / or surface-soldered plug and socket strips.

[0080] Using plug and socket connectors, it's possible to create a connection without soldering the circuit boards during assembly of the inductive charging device. This offers significant advantages during manufacturing.

[0081] This is especially the case with the version with the through-hole plug and socket connectors.

[0082] However, the use of plug and socket strips can also involve a soldering process when using surface-mounted or surface-soldered (surface-mounted device, SMD) plug and socket strips, which is, however, significantly simpler than a soldering process without the corresponding plug and socket devices.

[0083] In an alternative preferred variant, the upper conductor tracks are connected to the lower conductor tracks via flexible circuit boards.

[0084] The upper and lower circuit boards can still be designed as rigid circuit boards. The flexible circuit boards provide the connection via the vertical end faces and thus complete the winding for the coil around at least one flux guide element. This creates a combination of rigid and flexible circuit boards.

[0085] This combination is also known as rigid-flex PCBs. This is also a variant that allows for simpler and more suitable manufacturing than on-site soldering.

[0086] In a further advantageous embodiment, the upper circuit boards are connected to one another. Preferably, the upper circuit boards are designed as a common upper circuit board. Since the circuit boards themselves only represent the non-conductive base for the actual conductor tracks, no connection is established between the various sensor windings, which would influence their electromagnetic properties. Because the upper circuit boards are combined as a common circuit board, a mechanically much more stable component can be produced and the assembly of just one component instead of an upper circuit board for each sensor winding is also much easier. Using such a common upper circuit board, it is also easier to electrically interconnect the sensor windings, for example by connecting them in series or in parallel.This means fewer connecting conductors need to be routed to a more distant electronic device. In this variant, the area around the center of the sensor winding can be left out, allowing support elements to be arranged there. In this case, the common upper circuit board is designed in a ring shape in the center.

[0087] Another option is for the upper circuit boards to be clipped onto an inner circuit board ring, thus connecting them to each other. Clipping here means that a detachable connection is created between the upper circuit boards and the circuit board ring by hooking, clamping, or plugging them in.

[0088] The first sensor winding and / or the second sensor winding can be electrically connected to an electronic device. The electronic device can advantageously be arranged on or near the shielding and / or the cooling plate. The electronic device can take over the further processing and / or evaluation of the sensor signals from the sensor windings. For this purpose, the connecting lines required to connect the sensor winding to the electronic device can be routed through additional components such as a shield and / or through the cooling plate. This passed-through part of the connecting line can be implemented in the form of pin strips or flexible conductor tracks, analogous to the contact area of ​​the sensor winding. The respective circuit board can be of any shape and / or dimension.Preferably, the respective circuit board has a shape extending in the direction of the windings and a width that is transverse to the longitudinal direction of the windings, between 20 mm and 60 mm, in particular between 30 mm and 50 mm, preferably between 40 mm. This allows multiple windings, in particular adjacent to one another, to be located thereon. Preferably, the respective circuit board has a plurality of windings between 8 and 23, in particular between 11 and 19, preferably 15.

[0089] It may be advantageous to reduce the number of required feedthroughs. This can be achieved by connecting two or more of the sensor windings in series. Alternatively, or additionally, several connecting cables can be bundled and routed through a feedthrough.

[0090] In an alternative advantageous embodiment, the first sensor winding and the second sensor winding are designed as a stranded wire, in particular as a high-frequency stranded wire or as a wire.

[0091] A high-frequency stranded wire consists of several mutually insulated wires. This offers advantages because at high frequencies, the current flows primarily near the surface of a conductor, and the implementation with many individual conductors ensures the largest possible conductor surface area.

[0092] The term "wire" refers to the implementation as an insulated single wire, which is then wound in multiple turns. One advantage of implementing the sensor windings as high-frequency stranded wire or wire is that it is a proven and simple manufacturing method.

[0093] For this embodiment, an additional mechanical support structure can be used to prevent the high-frequency strand or wire from slipping on the flux guide element.

[0094] Alternatively, it is possible to glue the high-frequency strand or wire to the at least one flux guide element to prevent slipping.

[0095] A spacer structure can also be used to ensure a defined distance between the individual turns of the sensor winding.

[0096] Preferred embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical components.

[0097] It shows, schematically

[0098] Fig. 1 is a highly simplified representation of a vehicle with an inductive charging device,

[0099] Fig. 2 is a sectional view of an inductive charging device for a vehicle charging system,

[0100] Fig. 3 is a plan view of an inductive charging device according to the invention,

[0101] Fig. 4 is a plan view of an inductive charging device according to the invention in another embodiment,

[0102] Fig. 5 is a plan view of an inductive charging device according to the invention in a further embodiment,

[0103] Fig. 6 is a perspective view of a sensor winding arranged around a flux guide element,

[0104] Fig. 7 is a perspective view of an alternative sensor winding arranged around a flux guide element,

[0105] Fig. 8 is a sectional view of the sensor winding from Fig. 7 along the section line VIII, Fig. 9 is a sectional view through a part of an inductive charging device according to the invention with a corresponding thermal path,

[0106] Fig. 10 Top view of two versions of circuit boards for sensor windings,

[0107] Fig. 11 is a plan view of an inductive charging device according to the invention in an alternative embodiment,

[0108] Fig. 12 is a perspective view of an alternative sensor winding with pin and socket connectors arranged around a flux guide element,

[0109] Fig. 13 is a plan view of upper circuit boards for sensor windings for an inductive charging device according to the invention in a further embodiment.

[0110] Fig. 14 a sectional view through a part of an inductive charging device according to the invention with a lead-through of cables through a shield and / or cooling plate

[0111] Fig. 15 is a sectional view through part of another embodiment of an inductive charging device according to the invention.

[0112] If a part in the figures is designated by reference numerals separated by commas, this means that both descriptions apply to the specific designated part. In Fig. 1, for example, 1,1a means: This is an inductive charging device and this is also a mobile inductive charging device.

[0113] Fig. 1 shows a mobile inductive charging device 1a, which is arranged on a vehicle 2 with an energy storage device 3 and is positioned above a stationary inductive charging device 1b. During operation, energy can be transferred from the stationary inductive charging device 1b to the mobile inductive charging device 1a, and the energy storage device of the vehicle 3 can thereby be charged. The mobile inductive charging device 1a and the stationary inductive charging device 1b together form or are part of a vehicle charging system 8. In principle, it is also possible to operate the vehicle charging system 8 bidirectionally. In this case, energy can be temporarily transferred from the mobile inductive charging device 1a to the stationary inductive charging device 1b. The stationary inductive charging device 1b arranged on the ground in Fig. 1 can alternatively also be arranged sunk into the roadway (not shown here).In a recessed arrangement, the inductive charging device 1 b can be covered by certain layers of the road surface or can be flush with the road surface.

[0114] Fig. 2 shows a lateral section through an inductive charging device 1, 1a which includes several flux guiding elements 5 and an energy transmission winding 4, 4a and is mounted on a vehicle 2.

[0115] A corresponding arrangement exists for a stationary inductive charging device 1 b, except that it is arranged on a surface instead of on a vehicle 2 (not shown).

[0116] Fig. 3 shows a plan view of an inductive charging device 1 according to the invention. This can be a mobile inductive charging device 1a or a stationary inductive charging device 1b. In the present exemplary embodiment, eight flux guiding elements 5 are shown, which are arranged radially around the center 7 of the energy transmission winding 4 in the plane. Narrow gaps 27 are located between the flux guiding elements 5. The gaps also run radially around the center 7, thus the gaps run approximately in the main direction of the magnetic field lines (three magnetic field lines 14 are symbolically indicated here) that arise during energy transmission in the flux guiding elements 5. The energy transmission winding 4, which is concealed by the flux guiding elements 5 in the plan view, is indicated by dashed lines. The energy transmission winding 4 is a flat coil 10 here.A first sensor winding 9, 9a is arranged around one of the flux guide elements 5, and a second sensor winding 9, 9b is arranged around another flux guide element 5. The sensor windings are designed here as solenoids, also called cylindrical coils. The first sensor winding 9a is arranged axially symmetrically to the second sensor winding 9b with respect to the longitudinal direction of the vehicle 6. The first sensor winding 9a has a first radial longitudinal direction 11a, and the second sensor winding 9b has a second radial longitudinal direction 11b. The angle 12 between the first radial longitudinal direction 11a and the longitudinal direction.

[0117] 6 of the vehicle 2 is at least approximately equal to the angle 13 between the second radial longitudinal direction 11b and the longitudinal direction of the vehicle. The first radial longitudinal direction 11a and the second radial longitudinal direction 11b intersect or cross at least approximately in the center

[0118] 7 of the energy transmission winding 4. The first radial longitudinal direction 11a and the second radial longitudinal direction 11b run radially outwards from the center 7 of the energy transmission winding 4.

[0119] During the charging process, the vehicle 2 is positioned above the stationary inductive charging device 1b, and energy is transferred to the inductive charging device 1a. The flux guiding elements 5 perform the function of flux guiding. In the charging state, the field lines of the magnetic field run approximately radially in them. Three magnetic field lines 14 are symbolically indicated in Fig. 3. Since the first radial longitudinal direction 11a and the second radial longitudinal direction 11b are also aligned radially and thus at least approximately parallel to the magnetic field lines 14, only relatively little or no voltage is induced in the first sensor winding 9a and the second sensor winding 9b. This is important because the high power levels of the energy transfer and thus the high flux densities could otherwise easily lead to the sensor windings being destroyed.Therefore, no additional effort is necessary to prevent the destruction of the arrangement.

[0120] For reasons of clarity, not all of the elements or components already shown are again designated by reference numerals in Fig. 4 and Fig. 5. The elements or components no longer designated by a separate reference numeral in these figures are to be understood as labeled in the previous figures. Fig. 4 shows a plan view of a further exemplary embodiment of an inductive charging device 1 according to the invention. In contrast to the exemplary embodiment in Fig. 3, here the first sensor winding 9a runs around two flux guide elements 5 that are diagonally opposite one another with respect to the center 7 of the energy transmission coil 4. The second sensor winding 9b is correspondingly wound around two further flux guide elements 5, which are also diagonally opposite one another with respect to the center 7. Here, the first sensor winding 9a and the second sensor winding 9b intersect approximately in the center 7 of the energy transmission coil 4.

[0121] Fig. 5 shows a plan view of a further embodiment of an inductive charging device 1 according to the invention. Here, four sensor windings 9a, 9b, 9c and 9d with four radial longitudinal directions 11a, 11b, 11c, 11d are present. Each sensor winding is arranged around a different flux guide element 5. Two of the flux guide elements are located diagonally opposite each other with respect to the center 7 of the energy transmission coil 4. Together, the four sensor windings 9a, 9b, 9c and 9d again form a cross-shaped arrangement. An advantage over the arrangement in Fig. 4 is that the area around the center 7 of the energy transmission coil 4 is designed without a sensor winding 9. This means that mechanically necessary support elements (not shown) can still be arranged here. Fig. 6 now shows a flux guide element 5. A sensor winding 9 is arranged around this flux guide element. It is designed as a copper strand 15.

[0122] Fig. 7 shows a perspective view, and Fig. 8 shows a sectional view along section line VIII of Fig. 7, of an alternative embodiment of a flux guide element 5 with a sensor winding 9. Here, the sensor winding 9 is designed in the form of a printed circuit board 16 with conductor tracks 17. The upper conductor tracks 17a on the upper circuit board 16a are connected to the lower conductor tracks 17b on the lower circuit board 16b in such a way that they form a continuous winding.

[0123] Fig. 9 shows the thermal connection of the various components to a cooling plate 18 and / or a metallic shield 26. This cooling plate 18 or metallic shield 26 has not been shown in any of the previous embodiments for reasons of clarity, but can be present in all previous and subsequent embodiments. The cooling plate 18 can be solid, implemented as a thin sheet, or have fluid flowing through it. The cooling plate 18 can additionally assume the function of the metallic shield 26 or be designed as a separate component. There can also be only one cooling plate 18 or only one metallic shield 26. The energy transfer winding 4 transfers its heat via the lower circuit board 16b to the flux guide element 5. Here, the heat, together with the heat generated there, is conducted via the upper circuit board 16a to the cooling plate 18 or metallic shield 26.Since the circuit boards 16 do not have very good thermal conductivity, it is important that the circuit board material is only used where it is necessary.

[0124] Therefore, Fig. 10 shows two different possibilities for an optimized shape of a printed circuit board 16. The width of the printed circuit board 19 is significantly smaller in the longitudinal region 20 of the printed circuit board than in the contact region of the printed circuit board 21. The longitudinal region 20 of the printed circuit board is the region that runs along the top or bottom of the flux guide elements 5. In the right-hand embodiment, one of the two contact regions 21 is additionally designed with a semicircular, tapered end.

[0125] The previous embodiments always featured flux guide elements 5 that had no interruptions along the magnetic field lines that develop in the radial direction during the charging process. The gaps between the flux guide elements, as shown in Fig. 3 to Fig. 7, also always run radially. This is preferred with regard to guiding the magnetic field.

[0126] For manufacturing reasons, however, rectangular flux guiding elements 5, as shown in Fig. 11, are also conceivable. Here, however, the gaps 27 do not run parallel to the direction of the magnetic field lines established in the flux guiding elements 5. Here, too, it is possible to arrange the sensor windings 9a and 9b around the flux guiding elements 5, with the sensor windings 9a and 9b intersecting at least approximately in the center 7 of the energy transmission winding. In this embodiment, the same circuit board is used for both sensor windings 9a and 9b. The conductor tracks of the respective sensor windings 9a and 9b are located in different "layers" of the circuit board and therefore intersect here too without creating a short circuit. In Fig. 11, the energy transmission winding 4 also has a rectangular shape.

[0127] Fig. 12 shows a further alternative embodiment of the arrangement of a sensor winding 9 around a flux guide element 5. Here, too, the sensor winding 9 is formed from conductor tracks 17 on printed circuit boards 16. The connection between the upper conductor tracks 17a on the upper printed circuit board 16a and the lower conductor tracks 17b on the lower printed circuit board 16b is made by pin strips 22 and socket strips 23. Fig. 13 shows a further exemplary embodiment. Here, only the upper printed circuit boards 16a for the sensor windings 9a, 9b, 9c and 9d for an inductive charging device 1 are shown. Here, four upper printed circuit boards 16a for four sensor windings 9a, 9b, 9c and 9d are shown. Here, however, the upper printed circuit boards 16a are connected to one another in a ring shape in the region of the center 7 of the energy transmission winding 4. This has manufacturing advantages.In this embodiment, it is also still possible to attach mechanical supports in the middle of the sensor winding.

[0128] Fig. 14 shows a sectional view through part of an inductive charging device according to the invention with a lead-through of lines 24 through a shield 26 and / or through a cooling plate 18 to an electronic device 25. The shield 26 and the cooling plate 18 can also be the same component.

[0129] The upper conductor tracks 17a and the lower conductor tracks 17b are arranged around a flux guide element 5 and connected to one another in such a way that they form a sensor winding 9. This sensor winding 9 is connected to an electronic device 25 via two electrical lines per sensor winding for evaluation. These lines are connected to the upper conductor tracks 17a on the upper circuit board 16a. A metallic shield 26 and / or a cooling plate 18 is arranged above the sensor winding 9. The electronic device 25 is located on or above the metallic shield 26 and / or the cooling plate 18. Therefore, a feedthrough of the lines 24 through the metallic shield 26 and / or a cooling plate 18 is necessary here.For this purpose, in the present example, a recess is provided in the metallic shielding 26 and / or the cooling plate 18, and the lines can be routed through the recess through the metallic shielding 26 and / or the cooling plate 18 and connected to the electronic device 25 above the metallic shielding 26 and / or the cooling plate 18. It is not necessary for each sensor winding 9 to have a separate feedthrough of the lines 24 through the shielding 26 and / or the cooling plate 18. Multiple sensor windings 9 can also be interconnected—in series, in parallel, or in a combination—and then only one feedthrough of the lines 24 can be implemented for these multiple sensor windings 9.

[0130] Fig. 15 shows a sectional view through an alternative inductive charging device according to the invention. Here, too, a sensor winding 9 is realized from conductor tracks 17 on circuit boards 16 and arranged around a flux guide element 5. For this purpose, the upper conductor tracks 17a on an upper circuit board 16a are electrically connected to the lower conductor tracks 17b on a lower circuit board 16b. In this case, the upper circuit board 16a is not arranged directly above the flux guide element 5, and the lower circuit board 16b is not arranged directly below the flux guide element 5. The sensor winding 9 in the form of the two circuit boards 16 also encloses the shielding 26 and / or the cooling plate 18 as well as the energy transmission winding 4. The upper circuit board 16a is arranged above the shielding 26 and / or the cooling plate 18. The lower circuit board 16b is arranged below the energy transmission winding 4.

[0131] Reference list

[0132] 1 inductive charging device

[0133] 1a mobile inductive charging device

[0134] 1 b stationary inductive charging device

[0135] 2 vehicles

[0136] 3 Vehicle energy storage

[0137] 4 Energy transmission winding

[0138] 4a Energy transmission winding in mobile inductive charging device

[0139] 4b Energy transmission winding in stationary inductive charging device

[0140] 5 Flow guide element

[0141] 6 Longitudinal direction of the vehicle

[0142] 7 Center of the energy transmission winding

[0143] 8 Vehicle charging system

[0144] 9 Sensor winding

[0145] 9a first sensor winding

[0146] 9b second sensor winding

[0147] 9c third sensor winding

[0148] 9d fourth sensor winding

[0149] 10 flat coil

[0150] 11 radial longitudinal direction

[0151] 11 a first radial longitudinal direction

[0152] 11 b second radial longitudinal direction

[0153] 11 c third radial longitudinal direction

[0154] 11d fourth radial longitudinal direction

[0155] 12 first angle

[0156] 13 second angle

[0157] 14 Main direction of the magnetic field lines

[0158] 15 strands

[0159] 16 Circuit board a upper circuit board b lower circuit board

[0160] Conductor tracks a upper conductor tracks b lower conductor tracks

[0161] Cooling plate

[0162] Width of the circuit board

[0163] Longitudinal area of ​​the circuit board

[0164] Contact area of ​​the circuit board

[0165] pin header

[0166] socket strip

[0167] Implementation of the cables

[0168] Electronic device metallic shielding optionally with cooling function

[0169] Gap between flow guidance elements

Claims

Claims Inductive charging device (1 ) for a vehicle charging system (8) with an energy transfer winding (4) and at least one flux guide element (5) and at least one first sensor winding (9a) and a second sensor winding (9b), with the following features: - the flux guiding element (5) is suitable for guiding a magnetic field during an energy transfer which takes place between another inductive charging device (1) and the energy transfer winding (4) and - the first sensor winding (9a) and the second sensor winding (9b) are arranged around at least one of the at least one flux guide element (5). Inductive charging device (1) according to claim 1, characterized in that - the inductive charging device (1) is a mobile inductive charging device (1a) which is arranged on and / or in a vehicle (2) or that - the inductive charging device (1) is a stationary inductive charging device (1b). Inductive charging device (1) according to claim 1 or claim 2, characterized in that - the first sensor winding (9a) has a first radial longitudinal direction (11a), - the second sensor winding (9b) has a second radial longitudinal direction (11b), - the first radial longitudinal direction (11a) is arranged at an angle of 45° + / - 10°, preferably at an angle of 45°, to the longitudinal direction of the vehicle (6), - the second radial longitudinal direction (11b) at an angle of 45° + / -10 0 , preferably arranged at an angle of 45° to the longitudinal direction of the vehicle (6) and - the first radial longitudinal direction (11a) and the second radial longitudinal direction (11b) intersect at an angle of 70°–110°, preferably perpendicularly. Inductive charging device (1) according to one of the preceding claims, characterized in that - the first sensor winding (9a) has a first radial longitudinal direction (11a) and - the second sensor winding (9b) has a second radial longitudinal direction (11b) and - the first radial longitudinal direction (11a) and the second radial longitudinal direction (11b) intersect in the region of the area spanned by the energy transfer winding (4). Inductive charging device (1) according to one of claims 3-4, characterized in that the first radial longitudinal direction (11a) and the second radial longitudinal direction (11b) intersect at least approximately at the center (7) of the energy transfer winding (4). Inductive charging device (1) according to one of the preceding claims, characterized in that the inductive charging device (1) has at least four sensor windings (9), wherein - each two are arranged on opposite sides of the center (7) of the energy transmission winding (4) and - the four radial longitudinal directions (11 a, 11 b, 11 c, 11 d) of the four sensor windings run approximately through the center (7) of the energy transfer winding (4) and / or - the four radial longitudinal directions (11a, 11b, 11c, 11d) of the four sensor windings (9a, 9b, 9c, 9d) each form an angle of 45° ± 10°, preferably 45°, with the longitudinal direction of the vehicle (6). Inductive charging device (1) according to one of claims 3-6, characterized in that the first radial longitudinal direction (11a) and the second radial longitudinal direction (11b) are at least approximately parallel to the main direction of the magnetic field lines (14) that form during energy transfer in the flux guide element (5) in the area covered by the sensor winding. Inductive charging device (1) according to one of claims 3-7, characterized in that the first radial longitudinal direction (11a) and the second radial longitudinal direction (11b) intersect outside the center (7) of the energy transfer winding (4).Inductive charging device (1) according to one of the preceding claims, characterized in that the energy transfer winding (4) is designed as a flat coil (10) and / or the first sensor winding (9a) and the second sensor winding (9b) are designed as solenoids. Inductive charging device (1) according to one of the preceding claims, characterized in that several flux guide elements (5) are arranged radially around the center (7) of the energy transfer winding (4). wherein the gaps (27) between the flow guide elements (5) also extend radially. Inductive charging device (1) according to one of the preceding claims, characterized in that the first sensor winding (9a) and / or the second sensor winding (9b) are formed by conductor tracks (17) which are applied to at least one printed circuit board (16), preferably to at least two printed circuit boards (16a, 16b), in particular to at least one upper printed circuit board (16a) and at least one lower printed circuit board (16b). Inductive charging device (1) according to one of the preceding claims, characterized in that - the energy transmission winding (4) is thermally connected to one of the at least one flow guidance elements (5) and - the at least one flux guide element (5) is thermally connected to a cooling device, preferably a cooling plate (18) and / or to a metallic shield (26). Inductive charging device (1) according to claim 11 or claim 12, characterized in that at least one of the at least one circuit boards (16) has a narrower width (19) in a longitudinal region of the circuit board (20) than in a contact region of the circuit board (21). Inductive charging device (1) according to one of claims 11-13, characterized in that the first sensor winding (9a) and the second sensor winding (9b) consist of upper conductor tracks (17a) on the at least one upper circuit board (16a) and of lower conductor tracks (17b) on the at least one lower circuit board (16b). Inductive charging device (1) according to claim 14, characterized in that the upper conductor tracks (17a) are soldered to the lower conductor tracks (17b). Inductive charging device (1) according to claim 15, characterized in that the upper conductor tracks (17a) are connected to the lower conductor tracks (17b) via plated-through and / or surface-soldered connector strips and socket strips. Inductive charging device (1) according to claim 14, characterized in that the upper conductor tracks (17a) are connected to the lower conductor tracks (17b) via flexible printed circuit boards. Inductive charging device (1) according to any one of claims 14-17, characterized in that the upper printed circuit boards (16a) are connected to each other, in particular formed as a common upper printed circuit board (16a).Inductive charging device (1 ) according to one of claims 1-10, characterized in that the first sensor winding (9a) and the second sensor winding (9b) are designed as a stranded wire, in particular as a high-frequency stranded wire (15) or as a wire. *****

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