Device for contactless energy transmission with a primary coil arrangement and method for operating such a device

Abstract

Device for contactless energy transmission with a primary coil arrangement (1) and a secondary coil arrangement (2) inductively coupled thereto, wherein the secondary coil arrangement (2) can be arranged on a vehicle having a vehicle battery and the primary coil arrangement (1) can be assigned to an energy source, wherein at least one detection device (3) is assigned to the primary coil arrangement (1) and / or the secondary coil arrangement (2) with which an intermediate space (4) between the primary coil arrangement (1) and the secondary coil arrangement (2) can be monitored, characterized in that both the primary coil arrangement (1) and the secondary coil arrangement (2) are arranged on separate printed circuit boards (7, 7') and the at least one coil (6) of the primary coil arrangement (1) and the secondary coil arrangement (2) is designed as planar coils (9, 9'), wherein the planar coils have a first winding which is wound counterclockwise,and a second winding, which is wound in a clockwise direction, and a wire after the first winding is led in the center of the first winding into a second area of ​​the printed circuit board lower in the vertical direction of the printed circuit board, wherein the second winding is arranged in this second area and the planar coils (9, 9') are arranged in an inner layer (12, 12') embedded between two outer layers (10, 11; 10', 11') of the respective printed circuit board (7, 7').

Description

The present invention relates to a device for contactless energy transmission with a primary coil arrangement and a secondary coil arrangement inductively coupled thereto according to the preamble of claim 1, as well as a method for operating such a device, a primary coil arrangement for such a device, a secondary coil arrangement for such a device and a vehicle with such a secondary coil arrangement. Such devices and methods are used for the contactless charging of an energy storage unit in an electrically powered vehicle, such as a passenger car, a truck, a bicycle, a two-wheeled vehicle (motorcycle, scooter), a three-wheeled vehicle (trike), an aircraft, or a watercraft. They typically have a primary coil and a secondary coil, each housed in a plate-shaped casing and positioned opposite each other in such a way that an energy storage unit connected to the secondary coil can be charged by means of mutual induction. The primary coil is connected to a power source, such as a public power grid. For optimized energy transfer, it is necessary that the plate-shaped housings of the primary coil and the secondary coil are arranged opposite each other in two parallel, spaced-apart planes in such a way that the inductive coupling between the primary and secondary coils is optimized. The secondary coil is preferably located in an area of ​​the vehicle and the primary coil in an area outside the vehicle, such as a floor, wall or ceiling area of ​​a garage or parking space or parking area of ​​the vehicle. Various systems for contactless energy transfer are known from the state of the art. For example, patent DE 10 2009 033 237 A1 discloses a device for the inductive transmission of electrical energy from a stationary unit with at least one primary inductor to a vehicle located adjacent to it, with at least one secondary inductor. The stationary unit has a device for detecting the presence of an electrically conductive object within a predetermined space adjacent to the primary inductor. Furthermore, Japanese patent JP 2005-260 122 A discloses a module for contactless energy transmission in which both the energy output unit and the energy reception unit each comprise a circuit area, functional elements, a coil, and a core. The ferrite-based, plate-shaped core has an area for arranging the coil and an area for arranging the functional elements. The circuit and the coil are arranged in a row in their respective areas, which are bounded by the bends of the flexible printed circuit board (FPC). At the bends, the folded core is clamped by the FPC, with the coil located in the coil area and the circuit on the side opposite the coil area. Furthermore, patent specification US 2010 / 0328044A1 discloses an inductive energy transfer module comprising a plurality of transmitting inductors and a corresponding plurality of detector circuits. Each transmitting inductor is configured to supply inductive energy to an energy receiver circuit. Each detector circuit corresponds to one of the multiple transmitting inductors, and each detector circuit is configured to electromagnetically detect an energy receiver circuit in its vicinity. Each detector circuit is further configured such that, after electromagnetically detecting an energy receiver circuit, it controls the switching of its corresponding transmitting inductor to a power supply, thereby applying a supply voltage to the corresponding transmitting inductor, the supply voltage being used to generate inductive energy for transfer to the energy receiver circuit. Finally, patent document DE 20 2004 016 751 U1 discloses a transponder system for contactless inductive energy transfer from a stationary side with at least one reading coil arranged on the stator to a rotating side with at least one transponder coil arranged on a spindle. The area surrounding the reading coil is made of a highly electrically conductive material with low magnetic permeability. As soon as the primary and secondary coils are inductively coupled and energy transfer begins, a magnetic field with a high flux density is generated in the space between them. This high flux density is necessary to induce a sufficiently high current in the secondary coil to charge the energy storage unit with a corresponding power output within an acceptable time. Preferably, the charging power is approximately 3.5 kW, which causes heat to be generated in the space between the primary and secondary coils. This heat may attract small animals, such as cats, martens, and birds, to position themselves between the primary and secondary coils. Under certain circumstances, humans may also be attracted to the space.Human extremities, especially those of children and infants, may enter the space between the primary and secondary coils during the charging process. The heat generated by these objects does not, in itself, pose any health risks. However, the long-term effects of exposure to electromagnetic fields with such high flux densities on the physiology of living beings are not yet fully understood. Furthermore, it should be noted that people often carry electrically conductive objects, such as jewelry or implants, and pets like cats often wear collars containing metallic elements. The alternating electromagnetic field generated during the charging of the energy storage unit also induces a current in these metallic objects, which can potentially heat them to such an extent that severe burns may occur. Regardless of the physiological consequences for living beings present in the space between the primary and secondary coils during contactless energy transfer, the presence of foreign objects there, whether electrically conductive or not, results in a reduction of the energy transfer efficiency. Foreign objects in this space during contactless energy transfer oppose the oscillating magnetic field between the primary and secondary coils that facilitates the energy transfer, thus reducing the transferred power, even though the power supplied to the primary coil assembly remains unchanged. Consequently, the efficiency of the energy transfer decreases. Therefore, the space between the primary and secondary coil arrangement represents a problem area, as foreign bodies or even living beings can be located in this space or penetrate it during the charging process. The invention is therefore based on the objective of providing a device, a method, a primary coil arrangement, a secondary coil arrangement and a vehicle with which contactless energy transmission can be made safer and more efficient. This problem is solved by means of a device having all the features of claim 1, by means of a method of claims 11 and 13, with a primary coil arrangement of claim 15, with a secondary coil arrangement of claim 16 and with a vehicle of claim 17. Advantageous embodiments of the invention are found in independent claims 2 to 10, 12 and 14. The device according to the invention for contactless energy transmission is characterized in that at least one detection device is assigned to the primary coil arrangement and / or the secondary coil arrangement, with which an intermediate space between the primary coil arrangement and the secondary coil arrangement can be monitored. With at least one detection device, it is possible to scan the space between the primary coil arrangement and the secondary coil arrangement in order to detect foreign bodies not belonging to the device according to the invention, so that an ongoing charging process can be interrupted or a planned charging process cannot even begin. This ensures, firstly, that living beings entering or located in the space between the primary coil arrangement and the secondary coil arrangement are not exposed to the magnetic radiation emitted during a charging process, nor to potential heat radiation, and thus not to additional health risks.Secondly, this ensures that the energy transfer is carried out with the highest possible efficiency, since the space between the primary coil arrangement and the secondary coil arrangement is monitored for foreign bodies not belonging to the device according to the invention, which would reduce the efficiency of the energy transfer. The monitoring of the gap for the presence of foreign objects is preferably carried out before each charging process and particularly preferably also during the charging process, either continuously or at defined time intervals, by means of at least one detection device. According to a first embodiment of the invention, the at least one detection device is designed to monitor the space between the primary coil arrangement and the secondary coil arrangement directly or indirectly. Direct monitoring means that at least one detection device has at least one sensor capable of directly detecting foreign objects. Examples include ultrasonic sensors, radar sensors, infrared sensors, and optical sensors, which can detect a foreign object if it is located in the sensor's beam path. Such direct detection sensors have the advantage that they do not interfere with the magnetic field of the primary or secondary coil arrangement, allowing detection to be performed continuously or at predetermined intervals during energy transmission without interrupting the transmission process. Indirect monitoring, as used here, means that at least one detection device has at least one sensor with which foreign bodies can be detected indirectly. Examples include inductive sensors, also called capacitive sensors, which detect a foreign body by deformation of the electromagnetic field acting between the primary and secondary coil arrangement. The basic principle of an inductive sensor is preferably the control of the inductance by a physical quantity. An inductive sensor, for example a coil, operates according to the law of induction and emits an electromagnetic field that acts over a spatially limited area, in this case the space between the primary and secondary coils. This is also referred to as the active switching zone. If an electrically conductive foreign object, for example made of a metallic material, is introduced into this active switching zone, the magnetic field is deformed or damped, causing the inductive sensor to experience a change in impedance. If the damping is so great that the oscillation amplitude falls below a certain value, a comparator is triggered and outputs a signal via a power amplifier. Capacitive sensors are used, for example, to detect non-conductive materials such as wood, plastic, glass, etc., as foreign objects located in the space between the primary and secondary coil assemblies. Generally, the function of a capacitive sensor is based on changes in the electric field in the environment in front of its sensor electrode, i.e., the active zone. The capacitive sensor operates with an RC oscillator (resistor-capacitor oscillator). It measures the capacitance between the active electrode and the electrical ground potential. As a metallic or non-metallic foreign object approaches the active zone of the capacitive sensor, the capacitance increases, thus influencing the oscillation amplitude of the RC oscillator. This triggers a stage downstream of the RC oscillator, causing a switching amplifier within the sensor to change its output state. Consequently, the inductive or capacitive sensors measure the change in amplitude or resonance frequency caused by the presence of foreign bodies or living beings in the space between the primary coil arrangement and the secondary coil arrangement. However, when using capacitive or inductive sensors, it should be noted that the charging process itself must be interrupted or cannot be enabled as soon as a detection of the space between the primary coil arrangement and the secondary coil arrangement is carried out. In order to avoid interrupting the charging process, it may therefore be advantageous when using capacitive or inductive sensors to detect foreign objects in the space between the primary coil arrangement and the secondary coil arrangement only before the charging process. However, it is advantageous that the primary and secondary coil arrangements in the device according to the invention each have at least one coil that can be used as an inductive sensor. Therefore, it is not necessary to provide additional sensors to monitor the space between the primary and secondary coil arrangements. Of course, it is also possible to combine several, especially several of the sensor types described above. According to a further embodiment of the invention, both the primary coil arrangement and the secondary coil arrangement comprise at least one coil, wherein the number of coils in the primary coil arrangement and in the secondary coil arrangement is the same. This embodiment of the invention makes it possible to arrange a plurality of inductive or capacitive sensors in the device for monitoring the space between the primary coil arrangement and the secondary coil arrangement, thereby significantly increasing the sensitivity of the monitoring. Simultaneously, all these detectors, with the same number in the primary and secondary coil arrangements, can be used for energy transfer when appropriately oriented relative to each other.Therefore, a very efficient energy transfer with simultaneous high monitoring security is ensured, even if the energy transfer has to be briefly interrupted again and again to monitor the space between the primary coil arrangement and the secondary coil arrangement. According to the invention, both the primary coil arrangement and the secondary coil arrangement are arranged on separate printed circuit boards, wherein at least one coil of the primary coil arrangement and the secondary coil arrangement is designed as a planar coil. Known coil systems, or discretely wound coil systems, consist of a copper wire arranged around a core to form coil windings, with these coils typically having a height or thickness of at least approximately 1.5 cm to 2 cm. In contrast, the overall height of the circuit board-based device according to the invention is only a maximum of 1.2 cm to 1.5 cm, resulting in a low overall height. This design is particularly advantageous for the secondary coil assembly located in or on the vehicle, as it optimizes component size and weight. Further electrical components and / or circuits required for the overall system can be externally connected to the primary and / or secondary coil assembly using a precisely designed wiring configuration. Consequently, the device according to the invention, comprising printed circuit boards and coils arranged therein, is characterized by an extremely flat design, mechanical robustness, and low weight. Furthermore, in contrast to known coil systems, such printed circuit board-based devices can be manufactured cost-effectively using existing conductor track manufacturing processes, without having to perform the significantly unreliable process of winding the wire onto the coil former. According to the invention, the planar coils are arranged in an inner layer embedded between two outer layers of the respective printed circuit board. The outer layers can thus serve as a kind of protective layer for the inner layer. The inner layer is understood here to be a printed circuit board system, which may optionally consist of several layers in which various electronic components are integrated. This allows additional components required for the system, such as surface-mount devices (SMDs) and / or through-hole components (THTs), i.e., electrical or electronic components such as resistors, transistors, capacitors, relays, etc., to be advantageously integrated into the printed circuit board.This can be done, for example, after the printed circuit board (PCB) containing the primary and / or secondary coil assembly has been manufactured using available PCB technologies. For this, the components are arranged and soldered or wired onto an outer layer of the PCB. Of course, this is also possible during the PCB manufacturing process itself, so that the components are applied or integrated onto an inner layer of the PCB. Consequently, it is possible for the components to be formed directly as a copper layer structure, while resistors, for example, can be printed onto the surface or into the hidden layers using special pastes, thus saving not only on components but also on their assembly.It is also conceivable that circuits are placed directly on or in the printed circuit boards (chip on board / chip in board), which are bonded directly to the board and protected by, for example, a drop of synthetic resin. In this respect, all the power electronics required for operating a device according to the invention can advantageously be applied to or embedded on the same circuit board. Preferably, the printed circuit boards have a plurality of layers arranged one above the other, wherein the primary or secondary coil arrangement and possibly also other electrical components are arranged in an inner layer enclosed by at least two further layers. The planar coils are advantageously designed in a round, oval or angular shape. According to the invention, the planar coils have a first winding which is wound counterclockwise and a second winding which is wound clockwise. According to the invention, after the first winding, a wire is guided in the center of the winding into a lower second area of ​​the printed circuit board (viewed in the vertical direction of the board), in which a second winding is arranged. This ensures that the wire can be fed into and led out of the printed circuit board at the same side area. Preferably, the planar coils of the primary and secondary arrangements are located in the inner layer of the respective printed circuit board. This means that the planar coils are covered by the outer layers of the respective printed circuit board and consequently protected from damage. Preferably, at least one planar coil with a winding arranged in two superimposed planes is arranged in or on the respective printed circuit board, although it is also conceivable that several of these coils are arranged in or on the printed circuit board. According to a further aspect of the invention, a plurality of coils are distributed essentially uniformly on the printed circuit board (PCB) comprising the primary coil arrangement and / or the secondary coil arrangement. These coils are then arranged essentially uniformly across the PCB and preferably lie in the same plane with respect to the thickness of the PCB to ensure the most efficient energy transfer possible. According to a particularly advantageous embodiment of the invention, a control device is provided which is communicatively connected to the detection device and which is configured to control the inductive coupling between the primary coil arrangement and the secondary coil arrangement depending on a monitoring result communicated by the detection device. This control device can establish, maintain, or break the inductive coupling depending on the monitoring result of the detection device. It has proven effective to include a comparison device that is communicatively linked to the detection device and is designed to compare the monitoring results communicated by the detection device with a reference result. By comparing the monitoring result with a reference result, it is possible to determine with relative certainty whether a foreign object is present in the space between the primary and secondary coil arrangement. An inventive method for operating a previously described device for contactless energy transmission with a primary coil arrangement and a secondary coil arrangement inductively coupled thereto, comprises the following method steps: a) positioning of the secondary coil arrangement relative to the primary coil arrangement, b) inductive coupling of the secondary coil arrangement with the primary coil arrangement, c) examination of the space between the primary coil arrangement and the secondary coil arrangement by a detection device and determination of a monitoring result, d) comparison of the monitoring result with a reference result, and e) further operation of the device based on the comparison according to a suggestion list. This inventive method, which is particularly useful when using the direct sensors described above, essentially monitors the space between the primary and secondary coil arrangements continuously or at predetermined intervals. The device then continues to operate according to a suggestion based on the monitoring result, which can be selected from a suggestion list by a control unit. In particular, the charging process can continue if, for example, a foreign object is present in the space between the primary and secondary coil arrangements, but disappears again within a tolerable time interval.The tolerable time interval can be set such that decoupling of the primary and secondary coil arrangement only occurs when the dose of electromagnetic radiation acting on the foreign object exceeds a predetermined heat or radiation input into the foreign object. Alternatively or additionally, the time interval can also be set such that decoupling occurs when the energy transfer falls below a predetermined efficiency and thus becomes ineffective. In any case, it is possible to transmit the corresponding action performed by the control unit to, for example, a mobile phone or a monitoring station via a communication device, so that the user is notified of the foreign object detection and can take action, such as manually removing the foreign object, to restore the device to efficient and safe operation. Alternatively, the inductive coupling between the primary and secondary coil arrangements can be broken if the comparison reveals a deviation of the monitoring result from the reference result that lies outside a predefined tolerance range. However, this has the disadvantage that no energy transfer occurs as long as the foreign object is located in the space between the primary and secondary coil arrangements. Another method according to the invention for operating a previously described device for contactless energy transmission with a primary coil arrangement and a secondary coil arrangement inductively coupled thereto, comprises the following method steps: a) positioning of the secondary coil arrangement relative to the primary coil arrangement, b) examination of the space between the primary coil arrangement and the secondary coil arrangement by a detection device and determination of a monitoring result, c) comparison of the monitoring result with a reference result, and d) further operation of the device based on the comparison according to a suggestion list. This inventive method, which is particularly useful when using the previously described indirect inductive or capacitive sensors, decouples the primary and secondary coil arrangements during monitoring. Therefore, the space between them is monitored before energy transfer. During the charging process, energy transfer is briefly interrupted at predetermined intervals by decoupling the primary and secondary coil arrangements to allow for further monitoring. Based on the monitoring results, energy transfer is restarted by inductively coupling the primary and secondary coil arrangements if no foreign object is detected, or the decoupling is maintained if a foreign object is detected. Preferably, before each charging process and also during the charging process, the space between the charging cables is searched for the presence of foreign bodies either continuously or at defined time intervals using appropriate detection devices. This method, like the previously described method, can also include both a time-based consideration to account for the temporal heat and / or radiation input into the foreign body, as well as communication with the user. According to a concluding aspect of the invention, the space between the primary coil arrangement and the secondary coil arrangement can be automatically cleaned by means of a cleaning device, preferably a pivotable or movable broom or brush device associated with the primary coil arrangement, when a foreign object is detected. In this way, the residence time of foreign objects in the space between the primary coil arrangement and the secondary coil arrangement is minimized, and communication with the user is unnecessary or only required if a fault occurs in the cleaning device or if the cleaning device is unable to remove the foreign object despite repeated attempts. Furthermore, both a primary coil arrangement and a secondary coil arrangement for a previously described device according to the invention, as well as a vehicle with such a secondary coil arrangement, are independently protected. Further objectives, advantages, features, and applications of the present invention will become apparent from the following description of an exemplary embodiment with reference to the drawing. All features described and / or illustrated, individually or in any meaningful combination, constitute the subject matter of the present invention, even independently of their compilation in the claims or their cross-references. Figure 1 shows a schematic diagram of a first embodiment of a device according to the invention, Figure 2 shows a schematic diagram of a second embodiment of a device according to the invention, Figure 3 shows a schematic diagram of the primary coil arrangement and the secondary coil arrangement of the first embodiment of a device according to the invention according to Figure 1, and Figure 4 shows a schematic diagram of the primary coil arrangement and the secondary coil arrangement of the second embodiment of a device according to the invention according to Figure 2. Figure 1 shows a schematic diagram of a first embodiment of a device according to the invention. A printed circuit board 7 comprising a primary coil arrangement 1 is arranged opposite a printed circuit board 7' comprising a secondary coil arrangement 2, forming a gap 4. As can be seen, the primary coil arrangement 1 and the secondary coil arrangement 2 are aligned longitudinally. Furthermore, the primary coil arrangement 1 and the secondary coil arrangement 2 are arranged parallel to each other longitudinally. Within the primary coil arrangement 1 and the secondary coil arrangement 2, coils 6 (not shown in detail) are arranged, which in this embodiment are designed as planar coils 9 within an inner layer 12, 12' of the primary coil arrangement 1 and the secondary coil arrangement 2, respectively.The number of individual planar coils 9 within the primary coil arrangement 1 and the secondary coil arrangement 2 can differ. However, it is recommended to use the same number of planar coils 9 within the primary coil arrangement 1 and the secondary coil arrangement 2, as this allows each planar coil to contribute to contactless inductive energy transfer from the primary coil arrangement 1 to the secondary coil arrangement 2. Also clearly visible is a power electronics component 13, 13' embedded in the inner layer 12, 12' of the respective printed circuit board 7, 7', whereby the inner layer 12, 12' can be composed of several layers. Preferably, the power electronics component 13, 13' is arranged in a different layer than the primary coil arrangement 1 or secondary coil arrangement 2, although an electronic connection exists between the power electronics component 13, 13' and the primary coil arrangement 1 or secondary coil arrangement 2, which is not shown here. The circuit boards 7, 7' of the primary coil assembly 1 and the secondary coil assembly 2 also have outer layers 10, 10' and 11, 11', between which the inner layer 12, 12' is embedded in a sandwich-like arrangement. The outer layers primarily serve to protect the primary coil assembly 1 and secondary coil assembly 2, as well as the inner layer containing the power electronics 13, 13', from mechanical damage. The circuit board 7 of the primary coil assembly 1 has, in contrast to the circuit board 7' of the secondary coil assembly 2, additional detection devices 3 pointing towards the space 4, which in the present embodiment are designed with sensors 5 for the direct detection of foreign bodies located in the space 4. Such sensors 5 can be, for example, ultrasonic sensors, X-ray sensors, infrared sensors, or optical sensors for image acquisition. Furthermore, the power electronics 13 of the printed circuit board 7, which includes the primary coil arrangement 1, comprises a control unit 8 and a comparator 14. By means of the comparator 14, the device according to the invention is able to compare the monitoring results of the space 4 measured by the detection units 3 with one or more reference results. If the monitoring result deviates from the reference result(s) by a certain degree, which is equivalent to the presence of a foreign object in the space 4, the control unit 8 can break any existing inductive coupling between the primary coil arrangement 1 and the secondary coil arrangement 2. However, it is also possible to maintain an existing inductive coupling between the primary coil arrangement 1 and the secondary coil arrangement 2, even with a foreign object in the space 4, until the power transferred from the primary coil arrangement 1 to the secondary coil arrangement 2 falls below a predetermined threshold. Both the transferred power and the radiant energy introduced into the foreign object can be determined using the power electronics 13, 13', without going into their structure in detail here. Should a foreign object remain in the space 4 for an extended period, a user of the vehicle containing the secondary coil assembly 2 or maintenance personnel of the space containing the primary coil assembly 1 can be informed by means of a communication device of the power electronics 13 or 13' (not shown here) and requested to rectify the fault, in particular to remove the foreign object from the space 4. This is all the more important because otherwise the user would assume that the energy storage unit of his vehicle is being charged by the device according to the invention, even though the control unit 8 has, due to the foreign object remaining in the space 4 for an extended period, broken the inductive coupling of the primary coil assembly 1 with the secondary coil assembly 2 and thus interrupted the charging process, and therefore the vehicle's energy storage unit is not being charged. Alternatively, it can also be provided that the circuit board 7, which has the primary coil assembly 1, is assigned a cleaning device (not shown here), for example a broom or brush device. This cleaning device can automatically clean a foreign object in the space 4 upon detection, so that the charging process of the vehicle's energy storage unit can continue without informing the user or maintenance personnel, and it is not necessary to break the inductive coupling of the primary coil assembly 1 with the secondary coil assembly 2. Fig. 2 shows a further embodiment of a device according to the invention, which functions in accordance with the embodiment described above in Fig. 1. However, in this case, the existing coils 6 or planar coils 9 of the primary coil arrangement 1 or the secondary coil arrangement 2 are used as inductive or capacitive sensors 5 of detection devices 3 for the indirect detection of foreign bodies in the space 4. Fig. 3 shows a schematic diagram of an inner layer 12, 12' of a printed circuit board 7, 7' of the second embodiment according to Fig. 2, comprising a primary coil arrangement 1 and a secondary coil arrangement 2 respectively, with inductive or capacitive monitoring of the space 4 (not shown here). The planar coils 9, 9' serve both for contactless inductive energy transfer between primary coil arrangement 1 and secondary coil arrangement 2 and as a detection device 3 or inductive or capacitive sensors 5. The coil 6, or planar coil 9, has a snail-shaped winding. The coil 6, or planar coil 9, and in particular the magnetic field it generates, or the monitoring of this generated magnetic field, can therefore be used to detect foreign bodies in the space 4. This is achieved, for example, by foreign bodies or living organisms located on the primary coil assembly 1 causing a deflection of the magnetic field and thus a change in the amplitude or the resonant frequency. Detection is preferably carried out by means of a primary coil arrangement 1, which is arranged in a road surface, a wall or ceiling area of ​​a garage, a parking space, etc. That is, the detection of foreign objects and living beings, or the monitoring of the "cleanliness" of the space, is carried out by means of the primary coil arrangement 1, which, as an energy transmission system, i.e., as a charging system, transfers energy to the secondary coil arrangement 2, which is preferably located in a corresponding area of ​​a vehicle. Therefore, no additional sensors 5 are required to detect foreign bodies in the space 4. Fig. 4 shows a schematic diagram of an inner layer 12, 12' of a printed circuit board 7, 7' of the first embodiment according to Fig. 1, comprising a primary coil arrangement 1 and a secondary coil arrangement 2, respectively, with direct monitoring of the space 4 (not shown here). Detection devices 3 with sensors 5, which are designed, for example, as ultrasonic sensors, X-ray sensors, infrared sensors, or optical sensors for image acquisition, can be arranged either in the corner regions of the printed circuit board 7, 7' and / or also in regions of the coil 6 or the printed circuit board 7, 7'. Such a detection device 3 can be used in both the primary coil arrangement 1 and / or the secondary coil arrangement 2. This means that both the energy transmission system (charging system) in the form of the primary coil arrangement 1, which transmits the energy without contact, and the energy reception system (charging system) in the form of the secondary coil arrangement 2, which receives the energy, can monitor the space 4 between the two coil arrangements 1 and 2, which are essentially identical in construction. By using detection devices 3 with sensors 5 for direct monitoring of the space 4, such as ultrasonic sensors, X-ray sensors, infrared sensors, optical sensors for image acquisition, the electromagnetic field generated in the space 4 is not deflected, so that detection of foreign bodies that may have entered the space 4 can take place at any time, i.e. before as well as during the charging process, without causing a delay in the charging process. Reference symbol list 1 Primary coil assembly 2 Secondary coil assembly 3 Detection device 4 Space 5 Sensor 6 Coil 7 Printed circuit board 7' Printed circuit board 8 Control device 9 Planar coil 9' Planar coil 10 Outer layer 10' Outer layer 11 Outer layer 11' Outer layer 12 Inner layer 12' Inner layer 13 Power electronics 13' Power electronics 14 Comparator device

Claims

Device for contactless energy transmission with a primary coil arrangement (1) and a secondary coil arrangement (2) inductively coupled thereto, wherein the secondary coil arrangement (2) can be arranged on a vehicle having a vehicle battery and the primary coil arrangement (1) can be assigned to an energy source, wherein at least one detection device (3) is assigned to the primary coil arrangement (1) and / or the secondary coil arrangement (2) with which an intermediate space (4) between the primary coil arrangement (1) and the secondary coil arrangement (2) can be monitored, characterized in that both the primary coil arrangement (1) and the secondary coil arrangement (2) are arranged on separate printed circuit boards (7, 7') and the at least one coil (6) of the primary coil arrangement (1) and the secondary coil arrangement (2) is designed as planar coils (9, 9'), wherein the planar coils have a first winding which is wound counterclockwise,and have a second winding which is wound in a clockwise direction and a wire is guided after the first winding in the center of the first winding into a second area of ​​the printed circuit board lower in the vertical direction of the printed circuit board, wherein the second winding is arranged in this second area and the planar coils (9, 9') are arranged in an inner layer (12, 12') embedded between two outer layers (10, 11; 10', 11') of the respective printed circuit board (7, 7'). Device according to claim 1, characterized in that the detection device (3) is configured to directly or indirectly monitor the space (4) between the primary coil arrangement (1) and the secondary coil arrangement (2). Device according to one of the preceding claims, characterized in that the at least one detection device (3) has at least one sensor (5) for monitoring the space (4) between primary coil arrangement (1) and secondary coil arrangement (2). Device according to one of the preceding claims, characterized in that both the primary coil arrangement (1) and the secondary coil arrangement (2) have at least one coil (6) and the number of coils in the primary coil arrangement (1) and in the secondary coil arrangement (2) is the same. Device according to one of the preceding claims, characterized in that power electronics (13, 13') for operating the device is applied to the printed circuit board (7, 7') having the primary coil arrangement (1) and / or the secondary coil arrangement (2). Device according to one of the preceding claims, characterized in that the planar coils (9, 9') are formed in a round, oval or angular shape. Device according to one of the preceding claims, characterized in that a plurality of sensors (5) are distributed substantially uniformly on the circuit board (7, 7') having the primary coil arrangement (1) and / or the secondary coil arrangement (2). Device according to one of the preceding claims, characterized in that the primary coil arrangement (1) and / or the secondary coil arrangement (2) is designed as an inductive sensor and / or capacitive sensor. Device according to one of the preceding claims, characterized in that a control device (13) is provided which is communicatively connected to the detection device (3) and which is configured to control the inductive coupling between primary coil arrangement (1) and secondary coil arrangement (2) depending on a monitoring result communicated by the detection device (3). Device according to one of the preceding claims, characterized in that a comparison device (14) is provided which is communicatively connected to the detection device (3) and which is configured to compare the monitoring results communicated by the detection device (3) with a reference result. A method for operating a device according to one of the preceding claims, wherein a) the secondary coil arrangement (2) is positioned relative to the primary coil arrangement (1), b) the secondary coil arrangement (2) is inductively coupled to the primary coil arrangement (1), c) a detection device (3) examines the space (4) between the primary coil arrangement (1) and the secondary coil arrangement (2) and determines a monitoring result, d) a comparison of the monitoring result with a reference result is carried out, and e) based on the comparison, the device is operated further according to a list of suggestions, wherein a decoupling of the secondary coil arrangement (2) and the primary coil arrangement (1) takes place after a foreign body is detected by the detection device (3) in the space (4) if a dose of the electromagnetic radiation acting on the foreign body exceeds a predetermined heat or radiation input into the foreign body. Method according to claim 11, characterized in that the inductive coupling between primary coil arrangement (1) and secondary coil arrangement (2) is eliminated if the comparison reveals a deviation of the monitoring result from the reference result that lies outside a predefined tolerance range. Method for operating a device according to any one of claims 1 to 10, wherein a) the secondary coil arrangement (2) is positioned relative to the primary coil arrangement (1), b) a detection device (3) examines the space (4) between the primary coil arrangement (1) and the secondary coil arrangement (2) and determines a monitoring result, c) a comparison of the monitoring result with a reference result is carried out, and d) based on the comparison, the device is operated further according to a suggestion list, wherein, after a foreign body is detected by the detection device (3) in the space (4) between the primary coil arrangement (1) and the secondary coil arrangement (2), the space (4) is automatically cleaned by means of a cleaning device. Method according to claim 13, characterized in that the secondary coil arrangement (2) is inductively coupled to the primary coil arrangement (1) if the comparison reveals a deviation of the monitoring result from the reference result that lies outside a predefined tolerance range. Primary coil arrangement (1) for a device according to any one of claims 1 to 10. Secondary coil arrangement (2) for a device according to any one of claims 1 to 10. Vehicle, comprising a secondary coil arrangement (2) according to claim 16.

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