Inductive charging device for a vehicle charging system

Abstract

The invention relates to an inductive charging device for a vehicle charging system, said inductive charging system comprising an energy transfer winding, at least one flux-guiding element, and at least one first sensor winding and one second sensor winding. The energy transfer winding has two sub-windings. The two sub-windings are electrically connected to one another such that, during operation, current flows through the two sub-windings in opposite rotational directions. The flux-guiding element is designed to guide a magnetic field during energy transfer, which takes place between another inductive charging device and the energy transfer winding, and the first sensor winding and the second sensor winding are arranged around 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, for example, 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 allows 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. In the present case, this is shown for the special arrangement of an energy transmission winding with two partial windings.The present invention proposes an inductive charging device for a vehicle charging system, comprising an energy transmission winding, at least one flux guiding element, and at least one first sensor winding and a second sensor winding, having the following features: the energy transmission winding has two partial windings, and the two partial windings are electrically interconnected such that current flows in the two partial windings in opposite directions of rotation during operation, and 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 element; and the second sensor winding is arranged around at least one of the at least one flux guiding element.

[0007] During inductive charging, energy is transferred in the form of a magnetic field between two inductive charging devices, usually between a stationary charging device and a mobile inductive charging device. 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 inductive charging, an energy transfer winding in an inductive charging device generates an alternating magnetic field. This alternating magnetic field induces a voltage in another energy transfer winding 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 inducing a voltage.

[0008] 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.

[0009] 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.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] In general terms, 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 less than one turn, for example 0.5 turns. Of course, an incomplete number of turns, such as 2.5 turns, is also possible. An energy transmission winding can take on various forms and, for example, consist of a high-frequency stranded wire with a diameter between 0.5 mm and 10 mm, preferably made of copper.

[0014] An energy transmission winding according to the invention consists of at least two partial windings and the two partial windings are electrically interconnected in such a way that current flows in the two partial windings in opposite directions of rotation during operation.

[0015] The two partial windings can each be implemented as a flat coil. The two partial windings can be electrically connected in series or in parallel. The two partial windings can each have a first electrical terminal connected to the outer end of the winding and a second electrical terminal connected to the inner end of the winding.

[0016] In one possible embodiment, the current in a winding flows through several turns in a circular path. It can do this clockwise or counterclockwise. There are therefore two possible directions of rotation in a winding. The direction of rotation is determined by the winding direction and the end (inner or outer end) from which the current flows. With alternating current, the direction of the current and thus the direction of rotation of the current changes continuously, but the basic principle remains the same.

[0017] The two partial windings can be implemented with opposite winding directions or with the same winding direction. If the two partial windings are implemented with the same winding direction, they are electrically connected in such a way that the current flows through the partial windings in opposite directions, i.e., the first partial winding flows from the inside out while the second partial winding flows from the outside in, and vice versa.

[0018] The two partial windings can be arranged next to each other in relation to the direction of travel. The two partial windings can be arranged one behind the other in relation to the direction of travel. An appropriate arrangement of the windings and the generation of two currents flowing in them with different directions of rotation is advantageous, as this has a beneficial effect on the resulting magnetic fields. During inductive charging, energy is transferred using an alternating magnetic field. The corresponding magnetic field lines are always closed, thus forming a circle. For each path of the magnetic flux - i.e. for each part of the magnetic field line - that leads from one inductive charging unit to the other inductive charging unit, there is also a corresponding return path. In order to reduce losses due to unwanted stray paths to a minimum, it is advantageous for the entire path (i.e. the forward and return path) of the magnetic flux to be well defined and guided.This is not the case with a simple flat coil, but is made possible by using two partial windings in which the current flows in opposite directions.

[0019] The sensor windings are required for the positioning process. If the vehicle is still some distance away, for example between 5 and 10 m, from the stationary inductive charging device, the stationary inductive charging device can emit a signal, preferably a magnetic field, which induces a voltage in the sensor windings. The emitted magnetic field can preferably be an alternating magnetic field and is as homogeneous and parallel as possible, with the main direction of the magnetic field lines running in the vehicle's longitudinal direction. With such a magnetic field, equal voltages are induced in both sensor windings when the vehicle is moving towards its target position, and a directional deviation between the vehicle and the target position results in different voltages induced in the two sensor windings.By comparing the voltages induced in the two sensor windings and evaluating them accordingly, 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 transmit 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 a turn, one turn, 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 of ​​between 0.01 and 2 mm. 2A conductor can be a stranded wire, 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 mm per 35 m. A flux guide element is suitable for guiding 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 magnetic field is influenced by the high permeability 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 highly magnetic 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 be arranged either 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 applied to 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. Alternatively, a stationary inductive charging device can also be located on walls or the like. It is also possible for it to be a stationary inductive charging device for a dynamic inductive charging process. During a dynamic inductive charging process, an energy storage device of a vehicle 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.A plurality of inductive charging devices according to the invention can be arranged one behind the other along the roadway.

[0026] A mobile inductive charging device can be installed on and / or in a vehicle. Generally speaking, this refers to the part of a vehicle charging system that moves with the vehicle.

[0027] 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 are each arranged at an angle between 15° and 75° to the longitudinal direction of the vehicle.

[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 corresponding 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.

[0033] Advantageously, the first radial longitudinal direction is arranged at an angle of 45° to the longitudinal direction of the vehicle and the second radial longitudinal direction is arranged at an angle of 45° to the longitudinal direction of the vehicle.

[0034] 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.

[0035] 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 that the first radial longitudinal direction and the second radial longitudinal direction intersect in the region of the area spanned by the energy transmission winding.

[0036] 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 respective partial winding, where no winding is present, but not the area located outside the power transmission winding.

[0037] 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.

[0038] 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.

[0039] In an alternative preferred embodiment, 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 outside the area spanned by the energy transmission winding.

[0040] An arrangement of the sensor windings inclined with respect to the vehicle's longitudinal direction is advantageous because it makes it easy to detect any directional deviation due to voltages of varying strengths induced in the sensor windings. However, it is also possible to arrange the sensor windings at an angle to one another such that the intersection point of their radial longitudinal directions lies outside the area of ​​the energy transfer winding. For example, the sensor windings can be arranged in a V-shape or a roof-shaped arrangement. The sensor windings can be arranged symmetrically to the longitudinal direction of the vehicle. In this case, the two sensor windings can converge towards the edge of the energy transfer winding or the edge of the inductive charging device, whereby the intersection point of the two sensor windings would lie in the extension of the sensor windings and outside the area of ​​the energy transfer.

[0041] The two sensor windings can be arranged near the edge of the inductive charging device that is closest to the other inductive charging device during the positioning process, or the two sensor windings can be arranged near the edge of the inductive charging device that is furthest away from the other inductive charging device during the positioning process.

[0042] The two sensor windings can be arranged on the side of the energy transmission winding on which the electrical contacts of the energy transmission winding are led to the outside. The two sensor windings can be arranged on the side opposite the side on which the electrical contacts of the energy transmission winding are led to the outside. In one embodiment, the two sensor windings cross. The fact that only the radial longitudinal directions of the two sensor windings cross is a weaker condition. It is also possible for the two sensor windings to be relatively short and arranged in a "V" shape. If one conceptually extends these two sensor windings in their radial longitudinal direction, these radial longitudinal directions cross, but not the two sensor windings themselves. The fact that the two sensor windings themselves cross is a stricter condition.Here, the sensor windings are longer than in a "V"-shaped arrangement and actually cross each other. The arrangement is "X"-shaped. In this embodiment, the sensor windings have a larger area in which voltage is induced than in embodiments in which only the radial longitudinal directions of the sensor windings intersect in the extension, and more voltage can be induced. In this case, the sensor windings actually cross each other, rather than just crossing along the extension of the sensor windings.

[0043] It is advantageous if, in this embodiment, the two sensor windings are arranged point-symmetrically to the center of the energy transmission winding.

[0044] It is advantageous 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 are at least approximately parallel to the main direction of the magnetic field lines that form during the energy transfer in the flux guide element in the area covered by the sensor winding.

[0045] 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.

[0046] In one embodiment, the sensor windings are arranged in regions of the energy transmission winding, in particular in outer regions of the energy transmission winding, in which the magnetic flux is less than 80% of the maximum magnetic flux, preferably less than 50% of the maximum magnetic flux, particularly preferably less than 20% of the maximum magnetic flux.

[0047] As already mentioned, it is advantageous if as little voltage as possible is induced in the sensor windings during energy transfer, since otherwise damage or destruction may occur. Alternatively or in addition to the possibility of aligning the sensor windings with respect to the magnetic field lines so that little voltage is induced, it is also possible to arrange the sensor windings in regions in which there is an overall low magnetic flux during energy transfer. It is particularly advantageous if the magnetic flux is less than 80% of the maximum magnetic flux, preferably less than 50% of the maximum magnetic flux, particularly preferably less than 20% of the maximum magnetic flux. In an energy transfer winding according to the invention with two partial windings, the maximum magnetic flux occurs particularly in the central region of the energy transfer winding.In contrast, the magnetic flux in the peripheral areas of the area spanned by the power transmission winding is relatively low. Such low magnetic fluxes do not cause damage or destruction.

[0048] Preferably, the energy transmission winding is designed as a coil with a double-D arrangement and / or the first sensor winding and the second sensor winding are designed as a solenoid.

[0049] If the two partial windings, in which the current can flow with different directions of rotation during operation, are arranged next to each other and the geometry of the two partial windings resembles a rectangle, or the letter D, this arrangement is referred to as a double-D arrangement or DD arrangement. This creates a favorable magnetic field for energy transfer with a favorable path for the magnetic flux. The double-D arrangement can be arranged in relation to the direction of travel so that the two partial windings are arranged next to each other or one behind the other. The partial windings can be implemented as a spiral flat coil, in particular as a circular spiral flat coil or in particular as 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).In this case, however, shapes such as square or rectangular, or even rectangle-like with rounded corners (rectangular spiral flat coil) are particularly preferable. The spiral lies in a single plane.

[0050] 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 necessarily 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 from a flat coil is that the windings are not in a single plane, but rather extend along an axis. However, two or more windings can also run parallel and thus be in the same plane, perpendicular to the axis.

[0051] The shape of the solenoid is well suited to detect a signal sent by the stationary inductive charging device during the positioning process.

[0052] In a further preferred embodiment, a plurality of flux guide elements extend parallel across the width of the energy transmission winding, with gaps between the flux guide elements running perpendicular to the longitudinal direction of the vehicle.

[0053] From a manufacturing perspective, it is 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 each other. Rectangular flux guide elements can be used for this purpose. These are easier to manufacture. This always results in smaller gaps between the flux guide elements. Advantageously, the two sensor windings are arranged at a distance from each other in the outer areas of the energy transfer winding.

[0054] The energy transfer winding used, with two partial windings, has the property that the magnetic flux during energy transfer is primarily localized in the inner region of the energy transfer winding, while the outer regions exhibit only a small amount of magnetic flux. It is advantageous to arrange the sensor windings so that as little voltage as possible is induced in them during energy transfer, since the high power levels during energy transfer could otherwise lead to damage to the sensor windings. This can be achieved by running the sensor windings as parallel as possible to the magnetic field lines during energy transfer, as this leads to a low induced voltage, or, as in this case, by positioning the sensor windings in regions where the overall magnetic field is low during energy transfer.

[0055] The energy transfer winding with its two sub-windings spans an approximately rectangular area. The outer regions of this area, and thus of the energy transfer winding, can be imagined as a notional rectangular ring area. At the center is the rectangular inner region, in which the magnetic flux is primarily located during energy transfer, which is why arranging the sensor windings in this area is less advantageous. The outer regions of the energy transfer winding can, for example, have the same area as the inner region of the energy transfer winding. The outer regions of the energy transfer winding can encompass the three outer sides of the respective sub-winding.

[0056] In a preferred embodiment, the two sensor windings are arranged around the same flux guide element or elements. From a manufacturing perspective, it is impossible or very difficult to produce a large flux guide element that covers the entire surface of the energy transmission coil or even extends beyond it. In one possible embodiment, flux guide elements can extend across the entire width of the energy transmission winding, and several flux guide elements can be arranged one behind the other along the length. This creates a gap between the flux guide elements. The two sensor windings can be arranged around the same flux guide element and, for example, can be located near the two outer ends of the flux guide element.The sensor windings can also be arranged around several flux guiding elements, for example in the outer regions of two flux guiding elements arranged one behind the other.

[0057] 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.

[0058] Here, the turns of a sensor winding are realized in the form of conductor tracks on printed circuit boards.

[0059] The conductor tracks can be made of copper, for example.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] In a preferred embodiment, the first sensor winding and the second sensor winding consist of upper conductor tracks on an upper circuit board and lower conductor tracks on a lower circuit board. The conductor tracks on the upper circuit board can be connected to the conductor tracks on the lower circuit board to form a spiral winding.

[0067] 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.

[0068] 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.

[0069] In one variant, the upper conductor tracks are soldered to the lower conductor tracks.

[0070] In one variant, the upper conductor tracks are connected to the lower conductor tracks via through-hole and / or surface-soldered plug and socket strips.

[0071] 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.

[0072] This is especially the case with the version with the through-hole plug and socket connectors.

[0073] However, the use of surface-mounted or surface-soldered (SMD) plug and socket strips may also involve a soldering process, which is, however, significantly simpler than a soldering process without the corresponding connectors. In an alternative preferred variant, the upper conductor tracks are connected to the lower conductor tracks via flexible printed circuit boards.

[0074] 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. This combination is also known as rigid-flex circuit boards. This is also a variant that allows for simpler and more suitable manufacturing than on-site soldering.

[0075] 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 that fewer connecting cables need to be routed to a more distant electronic device.

[0076] 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 shield and / or the cooling plate. The electronic device can then handle the further processing and / or evaluation of the sensor signals from the sensor windings.

[0077] 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 extending transversely 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 ones, 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] Alternatively, it is possible to glue the high-frequency stranded wire or cable to the at least one flux guide element to prevent slippage. A spacer structure can also be used to ensure a defined distance between the individual turns of the sensor winding.

[0083] 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.

[0084] 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.

[0085] It shows, schematically

[0086] Fig. 1 is a highly simplified representation of a vehicle with an inductive charging device,

[0087] Fig. 2 is a sectional view of an inductive charging device for a vehicle charging system,

[0088] Fig. 3 is a plan view of an inductive charging device according to the invention,

[0089] Fig. 4 is a plan view of an inductive charging device according to the invention in another embodiment,

[0090] Fig. 5 is a plan view of an inductive charging device according to the invention in a further embodiment,

[0091] Fig. 6 is a plan view of another inductive charging device according to the invention,

[0092] Fig. 7 is a perspective view of a sensor winding arranged around a flux guide element, Fig. 8 is a perspective view of an alternative sensor winding arranged around a flux guide element,

[0093] Fig. 9 Top view of two versions of circuit boards for sensor windings,

[0094] Fig. 10 is a plan view of another alternative inductive charging device according to the invention.

[0095] 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.

[0096] 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 1b can be covered by certain layers of the roadway or can be flush with the road surface. The longitudinal direction 6 of the vehicle is also shown. It is also possible for many stationary inductive charging devices 1b to be arranged one behind the other along the roadway, thus enabling dynamic charging (not shown). Fig. 2 shows a lateral section through an inductive charging device 1, 1a which contains several flux guiding elements 5 (only one flux guiding element 5 is visible in the section) and an energy transmission winding 4 and is mounted on a vehicle 2. The energy transmission winding 4 is designed here as a double-D coil 15. As indicated here by the main direction of the magnetic field lines 14, the magnetic flux is strongly localized between the inner section of the partial windings 4a, 4b and the central region of the partial windings 4a, 4b.In contrast, the area around the outer regions of the partial windings 4a, 4b exhibits a relatively low magnetic flux. A corresponding arrangement exists for a stationary inductive charging device 1b, except that it is mounted on a surface (not shown) instead of on a vehicle 2.

[0097] 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, three flux guiding elements 5 are shown, which are arranged parallel in the plane. Gaps 27 are between the flux guiding elements 5. The gaps run perpendicular to the longitudinal direction of the vehicle 6. 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 here is a double-D coil 15. The double-D coil 15 has two partial windings 4a, 4b. The partial windings 4a, 4b are arranged next to one another in the same winding direction.The two partial windings 4a, 4b are electrically connected in series such that the current in the first partial winding 4a flows through the windings from the inside to the outside, while the current in the second partial winding 4b flows through the windings from the outside to the inside, and vice versa. As a result, the current in the two partial windings 4a, 4b always flows with different directions of rotation. If the current flows clockwise through the left partial winding 4a, it flows counterclockwise through the right partial winding 4b. A first sensor winding 9, 9a is arranged in the left outer region around one of the flux guide elements 5, and a second sensor winding 9, 9b is arranged in the right outer region of the same flux guide element 5. The sensor windings 9a, 9b are designed here as solenoids, also called cylindrical coils. The sensor windings 9, 9a, 9b are shown in simplified plan view as black stripes in Figs. 3-6. In Fig. 7 respectively.However, Fig 8 shows two embodiments of how the sensor windings 9 are actually arranged around a flux guide element 5.

[0098] 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 6 of the vehicle 2 is at least approximately the same size as 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 in the region of the energy transmission winding 4. The sensor windings 9a, 9b are inclined such that they are closer to one another in the central region of the inductive charging device 1 than in the outer region of the inductive charging device 1.

[0099] 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 take on the function of flux guiding. Since the first sensor winding 9a and the second sensor winding 9b are arranged in the outer regions of the energy transmission winding 4, only relatively little or no voltage is induced in the sensor windings. This is important because the high energy transmission power and thus high flux densities could otherwise easily lead to the sensor windings being destroyed. Additional effort to prevent the arrangement from being destroyed is therefore not necessary. For reasons of clarity, not all of the elements or components already shown are referred to again in Figs. 4, 5 and 6. The elements or components no longer designated with a separate reference number in these figures.Components are to be understood as labeled in the previous figures. Fig. 4 shows a plan view of another exemplary embodiment of an inductive charging device 1 according to the invention. In contrast to the exemplary embodiment in Fig. 3, the sensor windings 9a, 9b are longer here and both enclose two flux guide elements 5 in their outer regions. The first radial longitudinal direction 11a and the second radial longitudinal direction 11b intersect here outside the area spanned by the energy transmission winding.

[0100] Fig. 5 shows an alternative embodiment according to the invention in which the sensor windings 9a, 9b are inclined such that they have a greater distance in the inner region of the inductive charging device 1 than in the outer region of the inductive charging device 1. The sensor windings 9a, 9b are arranged around a flux guide element 5 on the side of the energy transmission winding 4 on which the latter has its electrical connections.

[0101] In Fig. 5, the power transmission winding 4 is also designed in a double-D arrangement 15. However, in contrast to Fig. 3 and Fig. 4, the winding directions of the two partial windings 4a and 4b are not the same. Therefore, current can flow through both partial windings 4a and 4b simultaneously, either from the outside in or from the inside out. Due to the different winding directions, the respective current has a different direction of rotation. The two partial windings 4a, 4b can be electrically connected in parallel.

[0102] Fig. 6 shows a further alternative embodiment of an inductive charging device 1 according to the invention. As in Fig. 5, the two sensor windings 9a, 9b are inclined such that they have a greater distance in the inner region of the inductive charging device 1 than in the outer region of the inductive charging device 1. In contrast to Fig. 5, however, the sensor windings here are arranged around a flux guide element 5, which is arranged on the side opposite the electrical connections of the energy transmission winding 4.

[0103] In Fig. 6, an imaginary dotted line is also drawn, which approximately represents the separation between the inner region 24 of the energy transmission winding 4 and the outer regions 23 of the energy transmission winding 4. During energy transmission, the magnetic flux is mainly localized in the inner region 24 of the energy transmission winding 4, while the outer region is largely free of magnetic flux.

[0104] Fig. 7 now shows how the sensor windings 9, indicated only as a black stripe in Fig. 3-6, can be designed. Fig. 7 also shows schematically how the directions, in particular the radial longitudinal direction 11, are defined in a winding, in particular in a sensor winding 9. The example in Fig. 7 shows a cylindrical coil with five turns. The direction along which the winding was wound is the winding axis 17. The coil here has a rectangular, not square, cross-section. The direction along the longer side of the rectangle is called the radial longitudinal direction 11. If the cross-section is not rectangular, but elliptical, the radial longitudinal direction 11 runs along the main axis of the ellipse.

[0105] Fig. 8 shows a perspective view of an 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 18 with conductor tracks 22. The upper conductor tracks 22a on the upper printed circuit board 18a are connected to the lower conductor tracks 22b on the lower printed circuit board 18b in such a way that they form a continuous winding.

[0106] Fig. 9 shows two different possibilities for an optimized shape of a printed circuit board 18. 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.

[0107] Fig. 10 shows another alternative embodiment of an inductive charging device 1 according to the invention. The crucial difference from the exemplary embodiments in Figs. 3-6 is that the two partial windings 4a and 4b are arranged one behind the other along the direction of travel 6, not side by side. The two sensor windings 9a, 9b are still arranged symmetrically to the direction of travel 6, but now only in the partial winding 4b. All other exemplary embodiments shown in Figs. 3-6 can also be implemented accordingly with the partial windings 4a, 4b arranged one behind the other.

[0108] Reference list

[0109] 1 inductive charging device

[0110] 1a mobile inductive charging device

[0111] 1 b stationary inductive charging device

[0112] 2 vehicles

[0113] 3 Vehicle energy storage

[0114] 4 Energy transmission winding

[0115] 4a first partial winding

[0116] 4b second partial winding

[0117] 5 Flow guide element

[0118] 6 Longitudinal direction of the vehicle

[0119] 8 Vehicle charging system

[0120] 9 Sensor winding

[0121] 9a first sensor winding

[0122] 9b second sensor winding

[0123] 10 flat coil

[0124] 11 radial longitudinal direction

[0125] 11 a first radial longitudinal direction

[0126] 11 b second radial longitudinal direction

[0127] 12 first angle

[0128] 13 second angle

[0129] 14 Main direction of the magnetic field lines

[0130] 15 Double-D Coil

[0131] 16 Winding axis

[0132] 18 circuit board

[0133] 18a upper circuit board

[0134] 18b lower circuit board

[0135] 19 Width of the circuit board

[0136] 20 Longitudinal area of ​​the printed circuit board Contact area of ​​the printed circuit board Conductor tracks a Upper conductor tracks b Lower conductor tracks Outer areas of the energy transfer winding Inner area of ​​the energy transfer winding Gap between flux guide elements

Claims

Claims 1. Inductive charging device (1) for a vehicle charging system (8) with an energy transmission winding (4) and at least one flux guide element (5) and at least one first sensor winding (9a) and one second sensor winding (9b), with the following features: - the energy transmission winding (4) has two partial windings (4a, 4b) and - the two partial windings (4a, 4b) are electrically connected to one another in such a way that current flows in the two partial windings (4a, 4b) in opposite directions of rotation during operation and - the flux guiding element (5) is suitable for guiding a magnetic field during an energy transfer which takes place between a further 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).

2. 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).

3. 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 between 15° and 75° to the longitudinal direction of the vehicle (6), - the second radial longitudinal direction (11b) is arranged at an angle between 15° and 75° to the longitudinal direction of the vehicle (6).

4. Inductive charging device (1) according to claim 3, characterized in that - the first radial longitudinal direction (11a) is arranged at an angle of 45° to the longitudinal direction of the vehicle (6) and, - the second radial longitudinal direction (11b) is arranged at an angle of 45° to the longitudinal direction of the vehicle (6).

5. 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 area of ​​the surface spanned by the energy transmission winding (4).

6. Inductive charging device (1) according to one of claims 1-5, 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 outside the area spanned by the energy transmission winding (4).

7. 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) are at least approximately parallel to the main direction of the magnetic field lines (14) which form during the energy transfer in the flux guide element (5) in the area covered by the sensor winding.

8. Inductive charging device (1) according to one of the preceding claims, characterized in that the first sensor winding (9a) and the second sensor winding (9b) are arranged in regions of the energy transmission winding (4), in particular in outer regions (23) of the energy transmission winding (4), in which the magnetic flux is less than 80% of the maximum magnetic flux, preferably less than 50% of the maximum magnetic flux, particularly preferably less than 20% of the maximum magnetic flux.

9. Inductive charging device (1) according to one of the preceding claims, characterized in that the energy transmission winding (4) is designed as a coil in a double-D arrangement (15) and / or the first Sensor winding (9a) and the second sensor winding (9b) are designed as a solenoid.

10. Inductive charging device (1) according to one of the preceding claims, characterized in that a plurality of flux guiding elements (5) extend parallel across the width of the energy transmission winding (4), wherein gaps (27) between the flux guiding elements (5) run perpendicular to the longitudinal direction of the vehicle (6).

11. Inductive charging device (1) according to one of the preceding claims, characterized in that the two sensor windings (9a, 9b) are arranged at a distance from one another in the outer regions (23) of the energy transmission winding (4).

12. Inductive charging device (1) according to one of the preceding claims, characterized in that the two sensor windings (9a, 9b) are arranged around the same flux guiding element (5) or the same flux guiding elements (5).

13. 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 (22) which are applied to at least one printed circuit board (18), preferably to at least two printed circuit boards (18a, 18b), in particular to at least one upper printed circuit board (18a) and at least one lower printed circuit board (18b).

14. Inductive charging device (1) according to claim 13, characterized in that at least one of the at least one printed circuit boards (18) in a Longitudinal region of the circuit board (20) has a smaller width (19) than in a contact region of the circuit board (21).

15. Inductive charging device (1) according to claim 13 or claim 14, characterized in that the first sensor winding (9a) and the second sensor winding (9b) consist of upper conductor tracks (22a) on the at least one upper circuit board (18a) and of lower conductor tracks (22b) on the at least one lower circuit board (18b).

16. Inductive charging device (1) according to one of claims 1 - 12, 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 or as a wire.

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