Inductive charging device for a vehicle charging system

Abstract

The invention relates to an inductive charging device (1) for a vehicle charging system (8) comprising an energy transmission winding (4) and at least one flux-guiding element (5). An inductive charging device according to the invention has a close-range positioning transmitter (NAH-POS) which is suitable for generating at least one close-range positioning signal (NAH-SIG), and a remote-positioning transmitter (FERN-POS) which is suitable for generating at least one remote-positioning signal (FERN-SIG).

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 and to a vehicle charging system.

[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 them. The double-winding system shown is used as a sensor for only one method that detects a positional deviation. Such a method can become imprecise or no longer function adequately at a minimal distance.

[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 at the outset, in particular those which enable a positioning method over the largest possible range of distances.

[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.Sensors capable of detecting a corresponding positional deviation are 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 at the greatest possible distance between a stationary inductive charging device and a mobile inductive charging device in the vehicle, as well as function until a sufficiently accurate positioning is achieved.

[0006] 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 comprising a near-positioning transmitter capable of generating at least one near-positioning signal and a remote-positioning transmitter capable of generating at least one remote-positioning signal.

[0007] 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.

[0008] 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.

[0009] 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.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] Further important features and advantages of the invention emerge from the subclaims, from the drawings and from the associated description of the figures based on the drawings.

[0014] An inductive charging device has an energy transfer winding which can efficiently receive a magnetic field from another energy transfer winding during the charging process and / or emit a magnetic field. Preferably, power levels of 3 kW to 500 kW can be transferred, particularly preferably 3 kW to 50 kW. A coil is generally defined here as a component for generating or receiving a magnetic field. A coil can consist of a winding and optionally further 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 revolution of a conductor. Generally speaking, 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.

[0015] 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.

[0016] 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 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.

[0017] A positioning transmitter is a device that enables the transmission of at least one positioning signal. A positioning transmitter can consist of multiple elements, which can also be spatially separated from one another. It is also possible for a positioning transmitter to transmit multiple positioning signals. A positioning transmitter is used to generate the positioning signals for a positioning method.

[0018] For optimal positioning, it is important, on the one hand, to achieve the greatest possible range, i.e., positioning is possible at the greatest possible distances between the two inductive charging devices. On the other hand, it is important that positioning is still possible even at short distances between the two inductive charging devices, until sufficiently accurate positioning is achieved.

[0019] The distances here always refer to a distance from an optimal positioning. For stationary inductive charging devices arranged on or in the ground, optimal positioning can be achieved if the two center points of the inductive charging devices are located vertically one above the other in a plane parallel to the ground. In this case, the distances are always determined relative to these center points. The distance between the two inductive charging devices here therefore refers to the distance between the two center points of the two inductive charging devices relative to the plane parallel to the ground. Different positioning methods can be optimal for different ranges of distances between the two inductive charging devices.For example, a positioning method that achieves the greatest possible range, i.e., the greatest possible distance between the two inductive charging devices, may be insufficient for short distances. A positioning method that delivers precise values ​​for short distances may have too short a range. It is therefore advantageous to combine two positioning methods that deliver sufficient or optimal values ​​for different distance ranges between the two inductive charging devices. It may also be advantageous to use different positioning transmitters for the two positioning methods.

[0020] The terms "near positioning" and "far positioning" refer to two different distance ranges between the two inductive charging devices or their two center points. The distance ranges may overlap. The terms "near positioning" and "far positioning" explicitly do not refer to a near- or far-field property of electromagnetic waves.

[0021] A near-positioning transmitter is a positioning transmitter that can transmit positioning signals that are sufficient or optimal for positioning at relatively short distances between the two inductive charging devices. A near-positioning transmitter is suitable for transmitting a near-positioning signal during a positioning process. In particular, a near-positioning transmitter can transmit near-positioning signals that are suitable for positioning up to a sufficiently precise position.

[0022] A close positioning can cover an area up to a maximum distance of the close positioning. The maximum distance refers to the separation between the two inductive charging devices. The maximum distance refers to the distance to the optimal positioning. For a stationary inductive charging device arranged on or underground, the optimal positioning is when the two centers of the inductive charging devices are located one above the other. The maximum distance therefore refers to the distance between the two centers in the travel plane of the two inductive charging devices.

[0023] The maximum distance for close positioning can be less than two meters. Preferably, the maximum distance can be one meter. Close positioning thus preferably covers a distance of a few centimeters to one meter between the centers of the two inductive charging devices.

[0024] A remote positioning transmitter is a positioning transmitter that can transmit one or more positioning signals that are sufficient or optimal for positioning at relatively large distances between the two inductive charging devices. A remote positioning transmitter is suitable for transmitting a remote positioning signal during a positioning process. In particular, a remote positioning transmitter can transmit remote positioning signals that are sufficiently accurate for positioning up to a maximum range. The maximum range is the maximum distance between the two inductive charging devices that can be achieved through the combination of a short-range and a long-range positioning method.

[0025] Remote positioning can cover a range between a minimum and a maximum distance for remote positioning. The maximum distance for remote positioning should be at least as great as the distance at which a driver can no longer see the stationary inductive charging device through the windshield when driving straight towards it. The maximum distance for remote positioning can be several meters. Preferably, the maximum distance for remote positioning can be between 5 and 15 m, particularly preferably 10 m. Remote positioning can have a minimum distance below which positioning is no longer possible using this method. Advantageously, the minimum distance for remote positioning is at least as great as the maximum distance for close positioning.However, it is also possible that the minimum distance for remote positioning is smaller than the maximum distance for close positioning. In this case, there is a short transition area in which positioning must be carried out without a positioning method. For example, positioning can simply continue in the corresponding direction after the last evaluated remote positioning signal until close positioning delivers analyzable signals. Alternatively, it is also possible that the minimum distance for remote positioning is greater than the maximum distance for close positioning. In this case, the two positioning methods overlap.

[0026] The minimum distance for remote positioning can be between 20 cm and 1 m. Preferably, the minimum distance for remote positioning can be approximately 0.5 m.

[0027] The term “far” therefore preferably refers to a distance range between 0.5 m and 10 m. The term “near” therefore preferably refers to a distance range of less than 1 m.

[0028] 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.

[0029] Preferably, the inductive charging device is a mobile inductive charging device which is arranged on and / or in a vehicle or, the inductive charging device is a stationary inductive charging device.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] Advantageously, the near-positioning transmission device has a plurality of near-transmission windings, preferably at least four near-transmission windings, which are arranged at a distance from one another.

[0035] A near-field transmitter winding is one or part of a transmitter coil that can generate a near-field positioning signal. The near-field positioning signal can be an alternating magnetic field and have a specific frequency or a specific frequency band. The frequencies of the near-field positioning signals can be in the range from 5 kHz to 150 kHz, preferably in the range from 110 kHz to 148.5 kHz, particularly preferably in the range from 120 kHz to 145 kHz. The frequencies used can, for example, be several of the following frequencies: 111.483 kHz and 111.982 kHz and 112.994 kHz and 113.507 kHz and 116.009 kHz. A transmitter coil can be significantly smaller than a power transmission winding and can also be smaller than a sensor winding. A near-field transmitter winding can, for example, be in the form of a flat coil. The near-transmitting windings can be spaced apart from the energy transmission winding and spaced apart from the orthe flux guiding elements. Alternatively, a near-transmission winding can also be arranged in the region of the energy transmission winding and / or in the region of the flux guiding elements. In principle, a near-transmission winding can be arranged in any level of an inductive charging device. For inductive charging devices arranged parallel to the travel level, this corresponds to an arrangement at different heights. A near-transmission winding can be arranged between the at least one flux guiding element and the energy transmission winding. Alternatively, a near-transmission winding can be in the same level as the energy transmission winding. In a further alternative embodiment, a near-transmission winding can be closer to the further inductive charging device, which forms the counterpart during an inductive charging process, than the energy transmission winding and the flux guiding elements.In other words, a near-transmitting winding can be arranged on the side of the energy transmission winding facing away from the flux guide elements. It is also possible for the near-transmitting windings to be arranged at a distance from the inductive charging device and to be associated with it only functionally. Using multiple near-transmitting windings allows for a simpler positioning process.

[0036] If the received signals can be assigned to the individual positioning signals of the near-field transmitter windings, the relative or absolute distance to the respective near-field transmitter windings can be determined, allowing positioning to be performed. For example, the relative distances to two adjacent near-field transmitter windings can be compared.

[0037] The use of at least four near-field transmitter windings is advantageous. They can, for example, be arranged in the shape of a rectangle around a target area. By simply comparing the intensities of the different positioning signals, positioning can be carried out both in the vehicle's longitudinal direction and perpendicular to the vehicle's longitudinal direction. A further advantage is that this provides redundancy, as two ratios are formed in each spatial direction. This is particularly relevant for the proposed system because parasitic effects can occur at very short distances between the near-field transmitter winding and the sensor winding, so that the signals no longer have their maximum directly at the position of the near-field transmitter winding, but rather a pronounced "dip" is present there. A "dip" is defined here as a local minimum between two local maxima.The position-dependent signal therefore has a characteristic curve with a "double hump." Such a curve leads to a distortion of the detected position. Since the effect of the pronounced "dip" in the spatial distribution only occurs at very short distances, the redundancy proposed here is advantageous, as it always allows the signals from the near-transmitting windings at greater distances to be evaluated.

[0038] The near-transmitting windings are particularly advantageous if they have a winding axis perpendicular to the ground.

[0039] A local transmitter winding can be designed as a flat coil. 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 shape 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 can lie in one plane. A flat coil is particularly suitable for use in a vehicle, since in this case the installation space along the height of a vehicle is limited. A flat coil is advantageous because it has the smallest possible extension in this direction.An extension in both dimensions parallel to the ground and perpendicular to the height of a vehicle is advantageous, as this maximizes the tolerance range for positioning in which the coupling between the energy transmission windings is still sufficient for energy transmission.

[0040] Alternatively, a near-field transmitter winding can be designed as a cylindrical coil. In this case, a cylindrical coil can be quite flat. A corresponding cylindrical coil can be wound around a winding former and have a height along the winding axis between 5 mm and 15 mm.

[0041] A near-transmit winding can be made of copper. A near-transmit winding can have between 10 and 50 turns. Preferably, a near-transmit winding has between 20 and 40 turns. A near-transmit winding particularly preferably has 28 turns. A near-transmit winding can have a diameter between 50 and 100 mm. For example, a near-transmit winding has a diameter of 72 mm.

[0042] Preferably, the near-transmitting windings are each suitable for generating a near-transmitting positioning signal. A near-transmitting winding, as part of an electrical coil, can generate an alternating magnetic field by applying an alternating electric current. This alternating magnetic field can, for example, induce an electrical voltage in another, more distantly arranged winding. This means that the same basic physical principle used for energy transmission, namely induction, can also be used for the transmission of positioning signals. This offers several advantages. First and foremost, certain components, such as electronic components and flux guide elements, can be used for both energy transmission and positioning signal transmission. An alternating electric current with an effective value of between 500 mA and 1 A can flow through the near-transmitting winding. The effective value of the alternating current is preferably 700 mA.

[0043] The near-positioning signals can be alternating magnetic fields with different frequencies or with the same frequency but different pulse width.

[0044] In a near-positioning method, various transmitted and received near-positioning signals can be compared and a deviation from an optimal position can be determined. For this purpose, several near-positioning signals must be generated that are distinguishable from one another. These near-positioning signals must differ from one another in one distinguishing criterion. One possible distinguishing criterion is frequency. The intervals between two frequencies can be between 0.1 and 1 kHz. The frequencies used can, for example, be four or more of the following frequencies: 111.483 kHz and 111.982 kHz and 112.994 kHz and 113.507 kHz and 116.009 kHz.

[0045] Another possibility is to choose only one frequency for all near positioning signals, but to use different pulse widths for the different near positioning signals as a distinguishing criterion.

[0046] Preferably, the remote positioning transmission device has a remote positioning signal winding, wherein the remote positioning signal winding is designed as a solenoid with a winding axis in the vehicle longitudinal direction or desired vehicle longitudinal direction and the flux guide element is suitable for guiding a magnetic field during an energy transfer process which takes place between a further inductive charging device and the energy transfer winding and the remote positioning signal winding encloses at least one of the at least one flux guide elements and the remote positioning signal winding is suitable for generating the remote positioning signal.

[0047] A remote positioning signal coil can transmit a positioning signal during a positioning operation.

[0048] A remote positioning signal winding can have multiple turns, preferably between 10 and 15 turns, particularly preferably 13 turns. For example, a remote positioning signal winding can generate an alternating magnetic field with a specific frequency based on an alternating current. The effective current of the alternating current in the remote positioning signal winding can be between 100 and 500 mA. The effective current of the alternating current is preferably 260 mA. In principle, a power transmission winding can also emit a positioning signal; however, it is advantageous, as proposed here, to use a separate remote positioning signal winding to generate a positioning signal. In particular, the remote positioning signal winding can generate magnetic fields that are more suitable for positioning and, in particular, enable a greater range with the same power.The power transmission windings are designed to couple as well as possible with their counterparts. Therefore, they generally do not have a long range when it comes to transmitting or receiving magnetic fields in the vehicle's longitudinal direction or the desired vehicle longitudinal direction. However, this is crucial for a positioning process.

[0049] During positioning, the maximum possible power or the maximum possible magnetic fields of the positioning signal are severely limited. They are significantly lower than is the case during an energy transfer process. During the positioning process, no vehicle is located on the stationary inductive charging device. Therefore, it is possible for a person, for example, to stand on the stationary inductive charging device. To ensure that the magnetic fields remain harmless to a person, they must not exceed flux densities of 27 pT or 6.25 pT, depending on the frequency range.

[0050] With a proposed remote positioning signal winding, it is possible to generate positioning signals that comply with the limit values ​​or reference values ​​and still allow a long range.

[0051] 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.

[0052] A stationary inductive charging device has a target vehicle longitudinal direction. This is the direction in which the vehicle's longitudinal direction should be after a successful positioning process.

[0053] If the remote positioning signal winding is located in a mobile inductive charging device of a vehicle, the winding axis of the remote positioning signal winding is aligned in the vehicle's longitudinal direction. If the remote positioning signal winding is located in a stationary inductive charging device, the winding axis of the remote positioning signal winding is aligned in the desired vehicle longitudinal direction.

[0054] The remote positioning signal winding can have an extension along the winding axis of between 10 mm and 60 mm. Preferably, the remote positioning signal winding has an extension along the winding axis of 40 mm.

[0055] In the proposed arrangement, the flux guide element guides a magnetic field for energy transfer during an energy transfer process and a magnetic field for positioning during a positioning process. Thus, the flux guide element performs a dual function, which is particularly advantageous because it allows for efficient use of material and installation space.

[0056] Particularly preferably, the remote positioning signal winding can be arranged around the entire width of the inductive charging device in order to cover the largest possible area and thus be able to generate the most homogeneous magnetic field possible. In one variant, the remote positioning signal winding is arranged around at least one of the at least one flux guiding elements and around the energy transmission winding. This is advantageous because the remote positioning signal winding can be arranged around an otherwise pre-assembled inductive charging device. Furthermore, the remote positioning signal winding spans a larger area if it is arranged around at least one of the at least one flux guiding element and around the energy transmission winding than, for example, if it is arranged around only one or more flux guiding elements.Thus, with the same power, the local maximum values ​​of the flux density are further reduced or, in other words, a higher power can be used while adhering to the flux density reference values ​​or flux density limit values, thus achieving a greater range.

[0057] The remote positioning signal can be an alternating magnetic field. It is advantageous if the same basic physical principle is used for a remote positioning process as for energy transmission, since certain components such as flux guide elements or electronic components can be shared. It can be particularly advantageous if both the near- and the far-positioning signal(s) are alternating magnetic fields. Here, too, other components can be shared. For example, both signal types—the far- and near-positioning signal—can be received with the same sensor.

[0058] An alternating magnetic field can be generated, for example, by means of a coil or a current-carrying winding of a coil. The alternating magnetic field can have a frequency between 100 and 150 kHz. Preferably, the frequency can be between 110 and 148.5 kHz. The frequency used can, for example, be one of the following frequencies: 145.560 kHz and 145.985 kHz and 146.843 kHz and 147.275 kHz. The invention also relates to a vehicle charging system with a mobile inductive charging device and a stationary inductive charging device, wherein the mobile inductive charging device is designed according to the invention and the stationary inductive charging device has a positioning receiving device, or the stationary inductive charging device is designed according to the invention and the mobile inductive charging device has a positioning receiving device.

[0059] It is advantageous if the transmission and reception of the positioning signals, both the remote positioning signals and the near positioning signals, takes place in the respective inductive charging device, since this is where the most accurate information about a precise positional or positional deviation can be obtained. One of the two inductive charging devices can be designed according to the invention and have a remote and a near positioning transmission device. The other inductive charging device can have a positioning reception device. A positioning reception device is suitable for receiving a near and / or a remote positioning signal.

[0060] Advantageously, the inductive charging device with the positioning receiving device has at least one flux guiding element and at least one sensor device with at least one first sensor winding and at least one second sensor winding.

[0061] The sensor device serves to receive the near and / or far positioning signals and thus forms the central element of the positioning receiving device.

[0062] A sensor winding according to the invention can be designed in various forms and can have half a turn, one turn, or preferably several turns. Of course, a partial 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 mm by 35 pm.

[0063] Preferably, the at least one flux guiding element is suitable for guiding a magnetic field during an energy transfer process which takes place between the mobile inductive charging device and the stationary inductive charging device, and the first sensor winding and the second sensor winding are arranged around at least one of the at least one flux guiding element.

[0064] 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 functions as a magnetic core for both the first sensor winding and / or the second sensor winding, as well as a magnetic core or

[0065] Flux guide element for the energy transmission winding. This eliminates the need for a separate flux guide element for the sensor winding, simplifying manufacturing.

[0066] 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.

[0067] The two sensor windings can be wound either by one or several

[0068] Flux guiding elements can be arranged around them or even other elements, such as around the energy transmission winding and / or around a cooling and / or shielding device.

[0069] In an advantageous 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 are arranged at least approximately perpendicular to one another.

[0070] 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.

[0071] 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.

[0072] The first sensor winding and the second sensor winding can have an extension of between 10 mm and 60 mm along the winding axis. Preferably, the first sensor winding and the second sensor winding have an extension of 40 mm along the winding axis.

[0073] The first sensor winding and the second sensor winding can preferably each have between 10 and 20 turns. Particularly preferably, the first sensor winding and the second sensor winding each have 15 turns. Particularly preferably, 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 arranged at least approximately axially symmetrically to the vehicle's longitudinal direction or to the desired vehicle's longitudinal direction.

[0074] If the two angles between the respective radial longitudinal direction of the sensor windings and the vehicle longitudinal direction or target vehicle longitudinal direction are approximately equal, this means that the sensor windings are arranged symmetrically to the direction of travel.

[0075] 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.

[0076] 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.

[0077] 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 of 45° + / - 10°, preferably at an angle of 45°, to the vehicle's longitudinal direction, and the first radial longitudinal direction and the second radial longitudinal direction intersect at an angle of 70°-110°, preferably perpendicularly. 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.

[0078] 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.

[0079] It shows, schematically

[0080] Fig. 1 is a highly simplified representation of a vehicle with an inductive charging device,

[0081] Fig. 2 is a sectional view of an inductive charging device for a vehicle charging system,

[0082] Fig. 3 is a plan view of an inductive charging device according to the invention with a near-positioning transmitter and a remote-positioning transmitter,

[0083] Fig. 4 is a plan view of an alternative inductive charging device according to the invention with a near-positioning transmitter and a remote-positioning transmitter,

[0084] Fig. 5 a flat coil as a near-positioning transmitter for a near-positioning transmitter device,

[0085] Fig. 6 shows an inductive charging device with a positioning receiving device for a vehicle charging system according to the invention, Fig. 7 shows an inductive charging device with a positioning receiving device for a vehicle charging system according to the invention,

[0086] Fig. 8 shows a vehicle during a positioning process with a vehicle charging system according to the invention.

[0087] Fig. 1 shows a mobile inductive charging device 1a, which is arranged on a vehicle 2 with an energy storage device 3 and 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, thereby charging the energy storage device of the vehicle 3.

[0088] 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 subsurface 35 in Fig. 1 can alternatively be recessed 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 be flush with the road surface.

[0089] 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, 10 and is mounted on a vehicle 2.

[0090] A corresponding arrangement exists for a stationary inductive charging device 1b, except that this is arranged on a surface (not shown) instead of on a vehicle 2. Fig. 3 shows a plan view of an inductive charging device according to the invention with a near-positioning transmitter NAH-POS and a remote-positioning transmitter FERN-POS. The near-positioning transmitter NAH-POS is implemented here in the form of four near-positioning windings 13. The remote-positioning transmitter FERN-POS is implemented here as a solenoid 42. During a positioning process, the remote-positioning transmitter FERN-SIG transmits a remote-positioning signal FERN-SIG in the form of an alternating magnetic field. During a positioning process, the near-positioning transmitter NAH-POS transmits several near-positioning signals NAH-SIG in the form of alternating magnetic fields, which differ, for example, in frequency.

[0091] Fig. 4 shows a plan view of an alternative inductive charging device according to the invention with a near-positioning transmitter NAH-POS and a remote-positioning transmitter FERN-POS. Here, too, the near-positioning transmitter NAH-POS is implemented as four near-transmission windings 13, and the remote-positioning transmitter FERN-POS as a solenoid 42. This embodiment shows an alternative arrangement of the flux guide elements 5. Furthermore, the remote-positioning signal winding 41 does not run centrally through the center of the inductive charging device 1, but is shifted toward an edge.

[0092] Fig. 5 shows a near-transmitting winding 13 which is designed as a flat coil 10.

[0093] Figure 6 shows a further inductive charging device which has a positioning receiving device 17 with two sensor windings 9a and 9b, which are part of a sensor device. 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 32 are 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) which 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 here is a flat coil 10.

[0094] The sensor windings are designed as solenoids, also called cylinder coils.

[0095] The first sensor winding 9a here runs around two flux guide elements 5 that are diagonally opposite each other 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 each other with respect to the center 7. The first sensor winding 9a is arranged axially symmetrically to the second sensor winding 9b with respect to the vehicle's longitudinal direction 6. The first sensor winding 9a and the second sensor winding 9b intersect at least approximately in the center 7 of the energy transmission coil 4.

[0096] 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 15 between the first radial longitudinal direction 11a and the vehicle longitudinal direction 6 is at least approximately the same size as the angle 16 between the second radial longitudinal direction 11b and the vehicle longitudinal direction 6.

[0097] 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. 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, only relatively little or no voltage is induced in the first sensor winding 9a and the second sensor winding 9b. This is important, since the high power levels of the energy transfer and thus the high flux densities could otherwise easily lead to the sensor windings being destroyed. Additional effort to prevent the arrangement from being destroyed is therefore unnecessary.

[0098] Fig. 7 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, 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. 6 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.

[0099] The inductive charging device according to the invention shown in Figs. 3 and 4 and the further inductive charging device shown in Figs. 6 and 7 can be part of a vehicle charging system 8 according to the invention. In this case, the one positioning receiving device 17 can receive signals from both the near-positioning transmitter NAH-POS and the remote-positioning transmitter FERN-POS. This is advantageous because one positioning receiving device 17 can serve two different positioning methods that function optimally at two different distance ranges.

[0100] Fig. 8 a) shows a vehicle 2 with a vehicle longitudinal direction 6 and with a mobile inductive charging device 1a during a positioning process above a stationary inductive charging device 1b with a target vehicle longitudinal direction 6a. The vehicle 2 drives directly towards the stationary inductive charging device 1b and the target vehicle longitudinal direction 6a is thus the same as the vehicle longitudinal direction 6. In addition to the energy transmission winding (not shown), the mobile inductive charging device 1a also contains a remote positioning signal winding 41 and four short-range transmission windings 13. The remote positioning signal winding 41 has a winding axis 34 and a radial longitudinal direction 11. The four short-range transmission windings 13 have winding axes perpendicular to the ground. The stationary inductive charging device 1b has, in addition to the energy transmission winding (not shown), two sensor windings 9a and 9b.Both sensor windings 9a and 9b each have a radial longitudinal direction 11a and 11b. Both sensor windings 9a and 9b are arranged symmetrically to the desired vehicle longitudinal direction 6a. This arrangement of the windings is particularly advantageous for positioning. The remote positioning signal winding 41 generates a fairly homogeneous magnetic field. A voltage is induced in the sensor windings 9a and 9b by the magnetic field of the remote positioning signal winding 41. If the vehicle moves exactly perpendicularly toward the stationary inductive charging device 1b, as shown in the left-hand sketch, an equal voltage is induced in both sensor windings 9a and 9b during the remote positioning process. From a certain distance, the near positioning process is used, and the near positioning signals NAH-SIG transmitted by the near transmission windings 13 are evaluated.

[0101] Fig. 8 b) shows an embodiment in which the remote positioning signal winding 41 and the four short-range transmission windings 13 are arranged in the stationary inductive charging device 1 b and the sensor windings 9a and 9b are arranged in the mobile inductive charging device 1a. The functioning of this embodiment is otherwise exactly the same. Shown here is a case in which the vehicle 2 does not drive perpendicularly towards the stationary inductive charging device 1 b, but deviates from it at an angle of approximately 45°. The vehicle's longitudinal direction 6 and the connecting line between the stationary inductive charging device 1 b and the mobile inductive charging device 1a are thus at a directional deviation angle of 45° to one another. In this case, the remote positioning signal winding 41 generates a magnetic field which is perpendicular to the first sensor winding 9a.Here, a maximum voltage is induced in the first sensor winding 9a during the remote positioning process. Furthermore, the magnetic field generated by the remote positioning signal winding 41 is approximately parallel to the second sensor winding 9b. Here, a minimal or no voltage is induced during the remote positioning process. Here, too, the near positioning process can take over from a certain distance.

[0102] Reference list inductive charging device a mobile inductive charging device b stationary inductive charging device vehicle

[0103] Vehicle's energy storage

[0104] Energy transmission winding

[0105] Flow guidance element

[0106] Vehicle longitudinal direction a Target vehicle longitudinal direction

[0107] Center of energy transmission winding

[0108] Vehicle charging system

[0109] Sensor winding a first sensor winding b second sensor winding c third sensor winding d fourth sensor winding 0 flat coil 1 radial longitudinal direction 1 a first radial longitudinal direction 1 b second radial longitudinal direction 1 c third radial longitudinal direction 1d fourth radial longitudinal direction 2 positioning signal 2a first positioning signal 2b second positioning signal 2c third positioning signal 2d fourth positioning signal 3 near-transmitting winding 3a first near-transmitting winding 3b second near-transmitting winding 3c third near-transmitting winding

[0110] 13d fourth near-transmitting winding

[0111] 14 Main direction of the magnetic field lines

[0112] 15 first angle

[0113] 16 second angle

[0114] 17 Positioning signal receiving device

[0115] 32 Gap between flow guide elements

[0116] 33 Reference point

[0117] 34 Winding axis

[0118] 35 Underground

[0119] 41 Remote positioning signal winding

[0120] 42 Solenoid

[0121] NAH-POS near positioning transmitter

[0122] FERN-POS remote positioning transmitter

[0123] NAH-SIG Near Positioning Signal

[0124] FERN-SIG Remote positioning signal

Claims

Claims Inductive charging device (1) for a vehicle charging system (8) with an energy transmission winding (4) and at least one flux guide element (5) with: a near-positioning transmitter (NAH-POS) which is suitable for generating at least one near-positioning signal (NAH-SIG), and a remote-positioning transmitter (FERN-POS) which is suitable for generating at least one remote-positioning signal (FERN-SIG). 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 one of the preceding claims, characterized in that the near-positioning transmitter (NAH-POS) has a plurality of near-positioning transmitter windings (13a, 13b, 13c, 13d), preferably at least four near-positioning transmitter windings (13a, 13b, 13c, 13d), which are arranged at a distance from one another. Inductive charging device (1) according to claim 3, characterized in that the near-positioning transmitter windings (13a, 13b, 13c, 13d) are designed with a winding axis (34) perpendicular to the base (35). Inductive charging device (1) according to claim 3 or claim 4, characterized in that the near-positioning transmitter windings (13a, 13b, 13c, 13d) are each suitable for generating a near-positioning signal (NAH-SIG). Inductive charging device (1) according to claim 5, characterized in that the near positioning signals (NAH-SIG) are alternating magnetic fields with different frequencies or with the same frequency but different pulse width.Inductive charging device (1) according to one of the preceding claims, characterized in that the remote positioning transmitter device (FERN-POS) has a remote positioning signal winding (41), wherein the remote positioning signal winding (41) is designed as a solenoid (42) with a winding axis (34) in the vehicle longitudinal direction (6) or desired vehicle longitudinal direction (6a), and the flux guiding element (5) is suitable for guiding a magnetic field during an energy transfer process which takes place between a further inductive charging device (1) and the energy transfer winding (4), and the remote positioning signal winding (41) encloses at least one of the at least one flux guiding elements (5), and the remote positioning signal winding (41) is suitable for generating the remote positioning signal (FERN-SIG).Inductive charging device (1) according to claim 6, characterized in that the remote positioning signal (FERN-SIG) is an alternating magnetic field. Vehicle charging system (8) with a mobile inductive charging device (1a) and a stationary inductive charging device (1b), wherein the mobile inductive charging device (1a) is an inductive charging device (1) according to one of claims 1-8 and the stationary inductive charging device (1b) has a positioning receiving device (17) or the stationary inductive charging device (1b) is an inductive charging device (1) according to one of claims 1-8 and the mobile. Inductive charging device (1a) has a positioning receiving device (17). Vehicle charging system (8) according to claim 9, wherein the inductive charging device with the positioning receiving device (17) has at least one flux guiding element (5) and at least one sensor device with at least one first sensor winding (9a) and at least one second sensor winding (9b). Vehicle charging system (8) according to claim 10, characterized in that the at least one flux guiding element (5) is suitable for guiding a magnetic field during an energy transfer process that takes place between the mobile inductive charging device (1a) and the stationary inductive charging device (1b), and the first sensor winding (9a) and the second sensor winding (9b) are arranged around at least one of the at least one flux guiding element (5).Vehicle charging system (8) according to claim 10 or claim 11, 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 arranged at least approximately perpendicular to one another. Vehicle charging system (8) according to one of claims 9-11, 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). the first radial longitudinal direction (11a) and the second radial longitudinal direction (11b) are arranged at least approximately axially symmetrically to the vehicle longitudinal direction (6) or to the desired vehicle longitudinal direction (6a).

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