Circuit arrangement for reactive power compensation in an inductive charging device, inductive charging device and system for inductive energy transfer

Abstract

The invention relates to a circuit arrangement for reactive power compensation in an inductive charging device, to an inductive charging device and to a system for inductive energy transmission. The circuit arrangement comprises two input terminals for connecting a voltage supply unit or a voltage acquisition unit, two output terminals for connecting a first energy coil or a second energy coil, a compensation circuit unit with a series capacitor arranged between one input terminal and one output terminal and / or a parallel capacitor arranged between two input terminals or between two output terminals, and at least one switching unit arranged in the compensation circuit unit for opening the electrical connection between the input terminal and the output terminal and interrupting the current flow through the energy coil connected at the output terminal.

Description

Technical Field

[0001] This invention relates to a circuit arrangement for reactive power compensation in an inductive charging device. The invention also relates to an inductive charging device, particularly for a vehicle charging system, and a system for inductive energy transfer. Background Technology

[0002] Systems used for inductive energy transfer typically include stationary inductive charging units (hereinafter also referred to as "inductive charging units" or "inductive charging equipment") and mobile inductive charging units. During charging operation, the energy coil of one inductive charging unit (hereinafter also referred to as the "first energy coil") serves as the primary coil, while the energy coil of the other inductive charging unit (hereinafter also referred to as the "second energy coil") serves as the secondary coil. In the following text, "energy coil" is also referred to as "power coil," "transfer coil," or "power transfer coil."

[0003] Such systems are typically used for inductive energy transfer to mobile applications, such as motor vehicles, which have mobile inductive charging devices. In mobile applications, the energy coil of the mobile inductive charging device is typically the secondary coil during charging operation. To perform inductive energy transfer, the primary coil generates an alternating magnetic field, which induces a voltage in the secondary coil. To achieve inductive energy transfer and improve its efficiency, the primary and secondary coils, and thus the energy coil of the inductive charging device, should be positioned relative to each other.

[0004] A system for inductive power transfer, particularly to mobile applications, is known from DE 102022203489 A1. This system comprises a fixed inductive charging device with fixed energy coils and a mobile inductive charging device with movable energy coils. Precise and robust identification of the relative positions of the energy coils with each other is achieved using a positioning device having four transmitting coils in one of the inductive charging devices and at least one receiver in the other. These transmitting coils generate mutually distinguishable positioning fields that interact with the at least one receiver, wherein whether the energy coils overlap are identified based on the proportions of these positioning fields.

[0005] An inductive charging device for a vehicle charging system is known from DE 102022120691A1. This inductive charging device includes an energy transfer winding, at least one flux guiding element, and at least one positioning signal winding. The positioning signal winding is implemented as a solenoid having a winding axis along the longitudinal direction of the vehicle or the desired longitudinal direction of the vehicle, and the flux guiding element is adapted to guide a magnetic field during an energy transfer process occurring between another inductive charging device and the energy transfer winding. The positioning signal winding surrounds at least one of the at least one flux guiding element and the energy transfer winding.

[0006] An inductive charging device for a vehicle charging system is known from DE 102022107568 A1. This inductive charging device has an energy transfer winding and at least one flux guiding element, and also has at least one first sensor winding and a second sensor winding. The flux guiding element is adapted to guide a magnetic field during energy transfer occurring between another inductive charging device and the energy transfer winding, and the first and second sensor windings are arranged around at least one of the at least one flux guiding element. In the sensor winding, a voltage is induced by the magnetic field of the positioning signal winding. This voltage is proportional to the magnetic field component perpendicular to the corresponding radial-longitudinal direction of the sensor winding. The position of the vehicle relative to the inductive charging device can be determined using these voltages. Summary of the Invention

[0007] The objective of this invention is to improve positioning accuracy.

[0008] According to one aspect of the present invention, a circuit device for reactive power compensation in an inductive charging device is provided, wherein the circuit device comprises: - Two input terminals for connecting to the voltage supply unit or voltage acquisition unit (Spannungsabnehmereinheit). - Two output terminals for connecting either the first energy coil or the second energy coil; - A compensation circuit unit, comprising a series capacitor arranged between one input terminal and one output terminal and / or a parallel capacitor arranged between the two input terminals or the two output terminals; and - At least one switching unit arranged in the compensation circuit unit for disconnecting the electrical connection between the input terminal and the output terminal and interrupting the current flow through the energy coil connected to the output terminal.

[0009] According to another aspect of the present invention, an inductive charging device is provided, which comprises: - The circuit device according to the invention; - A voltage supply unit or voltage acquisition unit connected to the two input terminals of the circuit device; - A first energy coil or a second energy coil connected to the two output terminals of the circuit device; and - A positioning device for identifying the relative positioning of the energy coils with respect to each other.

[0010] According to another aspect of the invention, a system for performing inductive energy transfer is provided, comprising a fixed inductive charging device (hereinafter also referred to as "Ground Assembly" (GA)) according to the invention and a mobile inductive charging device (hereinafter also referred to as "Vehicle Assembly" (VA)) according to the invention.

[0011] Preferred embodiments of the invention are defined in the dependent claims. It should be understood that the claimed inductive charging device and the claimed system for inductive energy transfer have preferred embodiments similar to and / or identical to the claimed circuitry, especially as defined in the dependent claims and as disclosed herein.

[0012] The inventors have recognized that by integrating one or more transmitting coils of a positioning device (hereinafter also referred to as a "Differential-Inductive-Positioning-System" (DIPS)) for generating the positioning magnetic field into an inductive charging device, mutual inductance is generated between these transmitting coils and the corresponding energy coils of the inductive charging device. Through this magnetic coupling, a voltage is induced in the energy coils during operation of the transmitting coils. Consequently, current also flows there due to the configuration of the compensation circuit unit—which typically has inductive and / or capacitive structural elements and can form an oscillating circuit—where current flow may occur even without compensation. This current, in turn, establishes a magnetic field that influences the original field of the transmitting coils through superposition.

[0013] The described effect occurs particularly in stationary inductive charging devices, where a transmitting coil is preferably provided. However, similar effects may also occur in mobile inductive charging devices due to the configuration of the compensation circuit unit essentially used therein. An oscillating circuit can also occur there, which may cause current to flow in the energy coil if, for example, a passive rectifier is directly connected to the coil and the voltage induced by the positioning coil exceeds the threshold voltage of the rectifier diode. Therefore, the receiving coil of the positioning device for detecting the positioning magnetic field of the mobile inductive charging device has mutual inductance with the corresponding energy coil. In the context of this invention, the term "vehicle" should be broadly understood to mean any mobile application, and therefore includes not only motor vehicles but also, for example, industrial vehicles, robots, forklifts, etc.

[0014] Furthermore, the coils of the fixed inductive charging device and the mobile inductive charging device form mutual inductance, and vice versa. Therefore, a matrix with mutual inductance between all the coils is ultimately generated.

[0015] By using a switching unit disposed between an input terminal and an output terminal of the circuit device according to the present invention, the electrical connection between the input terminal and the output terminal can be disconnected, thereby interrupting the current flow through the energy coil connected to the output terminal. During positioning operation—in which one or more transmitting coils of the positioning device of an inductive charging device generate a positioning magnetic field, and one or more receiving coils of the positioning device of another inductive charging device detect the positioning magnetic field—current flow in one or both energy coils and the interference with the positioning magnetic field can be prevented simply and effectively. This improves positioning accuracy.

[0016] Compensation circuit units for reactive power compensation are generally known in inductive charging devices and can be configured differently. In a preferred embodiment, the compensation circuit unit has a parallel capacitor arranged between the two input terminals or the two output terminals, and one or two series capacitors arranged between one input terminal and one output terminal. In another preferred embodiment, the compensation circuit unit has one or two series inductors arranged between one input terminal and one output terminal. The specific structure of the compensation circuit unit depends particularly on the desired behavior of the energy transfer system, i.e., whether a constant voltage should be provided by the energy transfer system. Different behaviors can be achieved depending on the design of the compensation. Furthermore, the configuration can also depend on how many degrees of freedom are present or required in the design. In a preferred configuration, LCC compensation is used.

[0017] The switching unit can be arranged in different locations. In a preferred embodiment, the at least one switching unit is arranged between an input terminal and an output terminal, particularly in series with the parallel capacitor and / or in series with the series capacitor. By disconnecting the switching unit, unwanted current flow through the compensation circuit unit can be quickly and effectively blocked.

[0018] The switching unit can also be configured differently and implemented using different structural elements. For example, the at least one switching unit may have a transistor (especially at least one MOSFET, Si-MOSFET, or SiC-MOSFET), a relay, a triac, or a thyristor. Other implementations are also possible.

[0019] Preferably, the at least one switching unit may have two anti-series MOSFETs connected in series, particularly Si-MOSFETs or SiC-MOSFETs, wherein a diode is connected in parallel with the corresponding MOSFET. Alternatively, the at least one switching unit may have two MOSFET circuits connected in parallel, each of which has two anti-series MOSFETs connected in series, particularly Si-MOSFETs or SiC-MOSFETs, wherein a diode is connected in parallel with the corresponding MOSFET. The specific structure of the switching unit depends particularly on the desired requirements. The advantage of using SiC-MOSFETs is that they have high breakdown voltage and may not be damaged in fault conditions. Parallel paths are advantageous, for example, when the current is very large during power transfer operation, because this allows current to be distributed across these MOSFETs and results in less heat generation.

[0020] Preferably, the circuit arrangement further includes a control unit for controlling the at least one switching unit such that the at least one switching unit closes when the energy coil connected to the output terminal is in energy transfer operation, inductively transmitting or receiving energy. In particular, control is performed in such a manner that the at least one switching unit closes only when the energy coil connected to the output terminal is in energy transfer operation. The control unit preferably also controls the operation of energy transfer and positioning, or is aware of the corresponding operating states of the energy transfer and positioning devices, which are controlled, for example, by its own or a shared control unit, so that appropriate control of the switching unit can be performed. For this purpose, for example in a preferred embodiment, the control unit is configured to obtain and / or determine operating information, which includes information about whether the energy coil is in energy transfer operation.

[0021] In a preferred embodiment, the control unit includes a voltage sensor for determining the operational information by measuring the voltage across the at least one switching unit. This allows identification of whether energy transfer operation is occurring, for example, by checking if the voltage exceeds a threshold. If the voltage is below the threshold, it is assumed that energy transfer operation is not occurring, but rather, for example, positioning operation is present.

[0022] In another embodiment, the control unit includes a voltage supply unit and a gate drive unit for manipulating the gate of at least one transistor. By correspondingly manipulating the gate of at least one transistor (e.g., a MOSFET) of the switching unit, the switching unit can be quickly and easily controlled (i.e., opened and closed).

[0023] The circuit arrangement according to the invention is particularly useful in inductive charging devices for vehicle charging systems, wherein a voltage supply unit or a voltage acquisition unit is connected to two input terminals of the circuit arrangement, a first energy coil or a second energy coil is connected to two output terminals of the circuit arrangement, and it has a positioning device for identifying the relative positioning of the energy coils relative to each other. Such inductive charging devices (without the circuit arrangement according to the invention) are applicable to embodiments of the circuit arrangement according to the invention, as known for example from the aforementioned DE 102022203489 A1 and DE102022120691A1.

[0024] The inductive charging device can be a fixed inductive charging device for installation on and / or in the ground, wherein the positioning device has at least one transmitting coil and / or positioning signal coil for generating a positioning magnetic field, particularly during positioning operation. The at least one transmitting coil can be configured, for example, as a transmitting coil known from DE102022203489 A1, for generating positioning fields that are distinguishable from each other. The positioning signal coil can be configured, for example, as a positioning signal winding known from DE 102022120691 A1 (e.g., as a solenoid having a winding axis along the longitudinal direction of the vehicle or the desired longitudinal direction of the vehicle), for generating and emitting a positioning signal during the positioning process.

[0025] Alternatively, the inductive charging device can be a mobile inductive charging device for installation on and / or in a vehicle, wherein the positioning device has at least one receiving coil for detecting the positioning magnetic field, particularly during positioning operations. The at least one receiving coil can be configured, for example, as a sensor coil known from DE 102022120691A1. For example, a first sensor winding having a first radial longitudinal direction and a second sensor winding having a second radial longitudinal direction can be provided.

[0026] In one embodiment of the inductive charging device, the circuitry includes a control unit for controlling the at least one switching unit such that the at least one switching unit is disconnected when the positioning device is in positioning operation, identifying the relative positioning of the energy coils with respect to each other, and when the energy coils are not in energy transfer operation, inductively transmitting energy. This ensures that no interference is generated during positioning operation by voltage induced in the energy coils.

[0027] In another embodiment of the inductive charging device, the voltage supply unit or the voltage acquisition unit respectively includes a converter unit and a converter control unit, wherein the converter control unit is configured to interrupt the current flow through the energy coil connected to the output terminal, particularly when the positioning device is in positioning operation that identifies the relative positioning of the energy coils with respect to each other and the energy coils are not in energy transfer operation that inductively transmits energy. Also in this configuration, it can be ensured that no interference is caused by the voltage induced in the energy coils during positioning operation.

[0028] In another embodiment, the first energy coil and / or the second energy coil each have at least two sub-coils, and each sub-coil is connected to the output terminal of a separate circuit for reactive power compensation. Therefore, each sub-coil (e.g., in the case of three sub-coils in a three-phase system) can have its own reactive power compensation, allowing for the individual interruption of current flow through the sub-coil connected to the output terminal for each sub-coil.

[0029] According to another aspect of the present invention, an inductive charging device is provided, which comprises: - i) a voltage supply unit and a first energy coil having at least two sub-coils, or ii) a voltage acquisition unit and a second energy coil having at least two sub-coils; - A positioning device for identifying the relative positioning of the energy coils with respect to each other; and - At least one switching unit for disconnecting i) the electrical connection between the voltage supply unit and the first energy coil or ii) the electrical connection between the voltage acquisition unit and the second energy coil or iii) the electrical connection between the sub-coils of the first energy coil or the sub-coils of the second energy coil, and for interrupting the current flow through the first energy coil or the second energy coil.

[0030] The invention can be advantageously applied even in inductive charging device embodiments that do not have a compensation circuit unit for reactive power compensation. In particular, when the energy coil has two (or more) sub-coils (especially those connected in parallel), the aforementioned problem may occur and lead to undesirable current flow even without such a compensation circuit unit. This current then establishes a magnetic field, which, through superposition, affects the original field of the transmitting coil.

[0031] It should be understood that the features mentioned above and those to be explained below can be used not only in the combinations given, but also in other combinations or individually, without departing from the scope of the invention. Attached Figure Description

[0032] Embodiments of the invention are presented in the following drawings and explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical parts. The drawings show: Figure 1 A very simplified illustration of a vehicle with an inductive charging device is shown. Figure 2 A cross-sectional view of an inductive charging device for a vehicle charging system is shown. Figure 3 A top view of an inductive charging device according to the present invention is shown, the inductive charging device having a near-field positioning transmitter and a far-field positioning transmitter; Figure 4 A top view of an alternative inductive charging device according to the invention is shown, the alternative inductive charging device having a near-field positioning transmitter and a far-field positioning transmitter. Figure 5 A flat coil is shown as a proximity positioning transmitter for a proximity positioning transmitting device. Figure 6 An inductive charging device is shown, having a positioning receiving device for a vehicle charging system according to the invention. Figure 7 An inductive charging device is shown, having a positioning receiving device for a vehicle charging system according to the invention. Figure 8 A vehicle equipped with a vehicle charging system according to the invention is shown during the positioning process; Figure 9 A known circuit arrangement for reactive power compensation in a stationary inductive charging device is shown. Figure 10 A known circuit arrangement for reactive power compensation in a mobile inductive charging device is shown. Figure 11 A schematic diagram illustrating another embodiment of an inductive charging device; Figure 12 A schematic diagram illustrating another embodiment of an inductive charging device; Figure 13 An embodiment of a circuit device according to the present invention for performing reactive power compensation is shown; Figure 14 Another embodiment of the circuit device according to the invention for performing reactive power compensation is shown; Figure 15-22 An exemplary configuration of a switching unit for a circuit device according to the present invention is shown; Figure 23 An embodiment of the circuit device according to the present invention, with a compensation circuit unit without parallel capacitors, is shown; Figure 24 Another embodiment of the circuit device according to the invention, with a compensation circuit unit without parallel capacitors, is shown; Figure 25 An embodiment of the circuit device according to the present invention, including a control unit, is shown; Figure 26 Another embodiment of the circuit device according to the present invention, including a control unit, is shown; Figure 27 An embodiment of an energy coil with two parallel extending energy coil windings is shown; Figure 28 Showing the energy coil Figure 27 The embodiments shown are embodiments of the circuit device according to the present invention; Figure 29 Another embodiment of the circuit device according to the invention with a secondary-side series compensation energy coil is shown; Figure 30 An embodiment of the fixed inductive charging device according to the invention, without a compensation circuit unit for reactive power compensation, is shown; and Figure 31 An embodiment of the mobile inductive charging device according to the invention is shown, which does not have a compensation circuit unit for reactive power compensation. Detailed Implementation

[0033] Figure 1 A mobile inductive charging device 1a is shown, which is arranged on a vehicle 2 having an energy storage device 3 and positioned above a fixed inductive charging device 1b. During operation, energy can be transferred from the fixed inductive charging device 1b to the mobile inductive charging device 1a, thereby charging the vehicle's energy storage device 3.

[0034] The mobile inductive charging device 1a and the fixed inductive charging device 1b together form or are part of the vehicle charging system 8. In principle, the vehicle charging system 8 can also operate bidirectionally. In this case, energy can be temporarily transferred from the mobile inductive charging device 1a to the fixed inductive charging device 1b. Figure 1 The fixed inductive charging device 1b, which is disposed on the foundation 35, can also be disposed recessedly in the lane (not shown here). In the case of the recessed arrangement, the inductive charging device 1b may be covered by a specific layer of the lane, or but flush with the surface of the lane.

[0035] Figure 2 A side sectional view through inductive charging devices 1 and 1a is shown. These devices include multiple flux guiding elements 5 and energy transfer windings 4 (energy coils) and are mounted on vehicle 2. A corresponding arrangement exists for fixed inductive charging device 1b, except that it is not mounted on vehicle 2 but on a foundation (not shown).

[0036] Figure 3 A top view of an inductive charging device according to the invention is shown, in which a circuit arrangement according to the invention can be applied, comprising a near-range positioning transmitter NAH-POS and a far-range positioning transmitter FERN-POS. The near-range positioning transmitter NAH-POS is here implemented as four near-range transmitting windings 13 (transmitting coils), but can also be implemented with more or fewer transmitting windings. The far-range positioning transmitter FERN-POS is here implemented as a solenoid (positioning signal winding). The far-range positioning transmitter FERN-POS emits a far-range positioning signal FERN-SIG in the form of an alternating magnetic field during the positioning process. The near-range positioning transmitter NAH-POS emits multiple near-range positioning signals NAH-SIG in the form of an alternating magnetic field during the positioning process; these near-range positioning signals are distinguished, for example, by frequency.

[0037] Figure 4 A top view of an alternative inductive charging device according to the invention is shown, in which a circuit arrangement according to the invention can be applied, having a near-field positioning transmitter NAH-POS and a far-field positioning transmitter FERN-POS. Here, the near-field positioning transmitter NAH-POS is also implemented as four near-field transmitting windings 13, and the far-field positioning transmitter FERN-POS is implemented as a solenoid. This embodiment shows an alternative arrangement of the flux guiding element 5. Furthermore, the far-field positioning signal winding 41 (positioning signal coil) does not pass centrally through the center of the inductive charging device 1, but is shifted towards the edge.

[0038] Figure 5A short-range transmitting winding 13, implemented as a flat coil, is shown.

[0039] Figure 6 Another inductive charging device 1 is shown, which has a positioning receiving device with two sensor windings 9a and 9b (receiving coils), the sensor windings being part of a sensor device. This could be a mobile inductive charging device 1a or a fixed inductive charging device 1b. In the current embodiment, eight flux guiding elements 5 are shown, arranged radially around the center 7 of the energy transfer winding 4 in a plane. However, there could be more or fewer flux guiding elements. Between the flux guiding elements 5 are narrow gaps 27. The gaps also extend radially around the center 7, so that the gaps approximately extend along the main direction of the magnetic field lines (three magnetic field lines 14 are symbolically drawn here) that appear in the flux guiding elements 5 during energy transfer. The energy transfer winding 4—which is obscured by the flux guiding elements 5 in the top view—is drawn with dashed lines. The energy transfer winding 4 is here a flat coil. The sensor winding is here constructed as a solenoid, also called a cylindrical coil.

[0040] The first sensor winding 9a extends around two flux guiding elements 5, which are diagonally opposite each other about the center 7 of the energy transfer coil 4. The second sensor winding 9b is correspondingly wound around two additional flux guiding elements 5, which are also diagonally opposite each other about the center 7. The first sensor winding 9a is arranged symmetrically with respect to the second sensor winding 9b about the longitudinal direction 6 of the vehicle. The first sensor winding 9a and the second sensor winding 9b cross at least approximately at the center 7 of the energy transfer coil 4.

[0041] 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 as the angle 16 between the second radial longitudinal direction 11b and the vehicle longitudinal direction 6.

[0042] During charging, vehicle 2 is positioned above fixed inductive charging device 1b, and energy is transferred to inductive charging device 1a. Magnetic flux guiding elements 5 function as flux guides. In the charging state, the field lines of the magnetic field extend approximately radially within these flux guiding elements. Since the first radial longitudinal direction 11a and the second radial longitudinal direction 11b are also radially aligned and therefore at least approximately parallel to the magnetic field lines, only a relatively small amount of voltage, or even no voltage, is induced in the first sensor winding 9a and the second sensor winding 9b. This is advantageous because, under the conditions of high power and therefore high flux density of energy transfer, damage to the sensor windings could otherwise be easily caused. The additional work required to prevent device damage is therefore unnecessary.

[0043] Figure 7 A top view of another embodiment of the inductive charging device 1 according to the invention is shown, in which the circuit arrangement according to the invention can be applied. Here are four sensor windings 9a, 9b, 9c, 9d with four radial and longitudinal directions 11a, 11b, 11c, 11d. However, there may be more or fewer sensor windings. Each sensor winding is arranged around a different flux guiding element 5. Two flux guiding elements are diagonally opposite each other about the center 7 of the energy transfer coil 4. These four sensor windings 9a, 9b, 9c, 9d also collectively form a cross-shaped arrangement again. Compared to... Figure 6 One advantage of this arrangement is that the area around the center 7 of the energy transmission coil 4 is designed without a sensor winding 9. Therefore, mechanically necessary support elements (not shown) can be arranged thereafter.

[0044] according to Figure 3 and Figure 4 The inductive charging device according to the present invention and according to Figure 6 and Figure 7 Another inductive charging device can be part of the vehicle charging system 8 according to the invention. Here, the positioning receiver can receive signals from both the near-range positioning transmitter NAH-POS and the far-range positioning transmitter FERN-POS. This is advantageous because two different positioning methods can be operated with a single positioning receiver, and these two different positioning methods function optimally within two different distance ranges.

[0045] Figure 8a) A vehicle 2 with a mobile inductive charging device 1a and a vehicle longitudinal direction 6 is shown above a fixed inductive charging device 1b with a desired vehicle longitudinal direction 6a during the positioning process. The vehicle 2 drives directly toward the fixed inductive charging device 1b, and the desired vehicle longitudinal direction 6a is therefore equal to the vehicle longitudinal direction 6. In the mobile inductive charging device 1a, in addition to the energy transfer winding (not shown), there is a long-range positioning signal winding 41 and four short-range transmitting windings 13. The long-range positioning signal winding 41 has a winding axis 36 and a radial longitudinal direction 11. The four short-range transmitting windings 13 have winding axes perpendicular to the foundation. In addition to the energy transfer winding (not shown), the fixed inductive charging device 1b has two sensor windings 9a and 9b. Each of the two sensor windings 9a and 9b has a radial longitudinal direction 11a and 11b. The two sensor windings 9a and 9b are arranged symmetrically with respect to the desired vehicle longitudinal direction 6a. This arrangement of the windings used for positioning is particularly advantageous. The long-range positioning signal winding 41 generates a fairly uniform magnetic field. Voltages are induced in the sensor windings 9a and 9b by the magnetic field of the long-range positioning signal winding 41. If the vehicle is driving perpendicularly towards the stationary inductive charging device 1b, as shown in the left figure, the same voltage is induced in both sensor windings 9a and 9b during the long-range positioning method FERN_V. The short-range positioning method NAH_V is used from a specific distance, and the short-range positioning signal NAH-SIG emitted by the short-range transmitting winding 13 is evaluated.

[0046] Figure 8 b) illustrates an embodiment in which a long-range positioning signal winding 41 and four short-range transmitting windings 13 are arranged in a fixed inductive charging device 1b, and sensor windings 9a and 9b are arranged in a mobile inductive charging device 1a. The operation of this embodiment is further consistent with the above reference. Figure 8 a) The operation described is the same. Here, it is shown that vehicle 2 is not driving perpendicularly towards the fixed inductive charging device 1b, but at an angle deviating by approximately 45°. Therefore, the longitudinal direction of the vehicle 6 and the connecting line between the fixed inductive charging device 1b and the mobile inductive charging device 1a are at a 45° angle to each other. In this case, the remote positioning signal winding 41 generates a magnetic field perpendicular to the first sensor winding 9a. Here, the maximum voltage is induced in the first sensor winding 9a during the remote positioning method FERN_V. The magnetic field generated by the remote positioning signal winding 41 is also approximately parallel to the second sensor winding 9b. Here, the minimum voltage or no voltage is induced during the remote positioning method FERN_V. Similarly, the near positioning method NAH_V can take over from a specific distance.

[0047] Utilizing Figures 1 to 8The Differential Inductive Positioning System (DIPS) for inductive charging systems described herein generates a specific positioning magnetic field by arranging several transmitting coils on a fixed inductive charging device (also known as a Ground Component (GA)) to ensure interoperability between the GA and mobile inductive charging devices (also known as Vehicle Components (VA)) from different manufacturers. Due to the coupling between the transmitting coils and one or more GA power coils (i.e., one or more energy coils of the fixed inductive charging device), the induced voltage generated in the GA power coils by the transmitting coils may induce a current in the GA power coils. The magnetic field generated by this current is superimposed on the positioning magnetic field, thereby affecting the distribution of the positioning magnetic field and thus the evaluation of the positioning field in the VA. The same problem exists between the transmitting coils and one or more VA power coils (i.e., one or more energy coils of the mobile inductive charging device). Here, a current can also be induced in the VA power coils, which in turn affects the positioning magnetic field.

[0048] Existing technologies for inductive charging systems include current standards from SAE J2954, ISO 19363, and IEC 61908. These standards are harmonized and provide so-called reference designs (mechanical descriptions of coil design and electrical descriptions of transmission paths) as guidance for product development and testing. Figure 9 The diagram shows a circuit arrangement for reactive power compensation in a GA with parallel compensation that conforms to SAE J2954. Figure 10 The diagram shows a circuit arrangement for reactive power compensation in a VA with parallel compensation conforming to SAE J2954.

[0049] Figure 9 and Figure 10 The circuit arrangement shown exemplarily has a compensation circuit unit with a capacitor C2 connected in parallel with the corresponding transmission coil LGA (for GA) or LVA (for VA) and two capacitors C1a and C1b connected in series therewith. Even assuming that such parallel compensation is typically applied for reactive power compensation, other circuit arrangements are conceivable.

[0050] Figure 11 A simplified schematic diagram of another embodiment of the inductive charging device 1b is shown, which, in addition to the energy coil 4, has both a positioning signal winding 41 and four transmitting coils 13. The positioning signal winding 41 is arranged as a solenoid in the central region around the energy coil 4 and the flux guiding element 5. The four transmitting coils 13 are arranged at the four corners above or below the energy coil 4. Figure 3 , Figure 4 and Figure 11Further details of the inductive charging device 1b shown are disclosed in DE102022203489 A1 and DE 102022120691A1, which are expressly referenced herein and their disclosures are incorporated herein by reference together.

[0051] Figure 12 A schematic diagram of another embodiment of the inductive charging device 1a is shown, which has two sensor windings 9a and 9b in addition to the energy coil 4. Figure 6 , Figure 7 and Figure 12 Further details of the inductive charging device 1a shown are disclosed in DE 102022107568A1, which is expressly referenced herein and its disclosure is incorporated herein by reference.

[0052] By using DIPS, i.e., especially GA, with a transmit coil and / or positioning signal coil (see, for example) Figure 3 , Figure 4 and Figure 11 The positioning device is integrated into the existing circuitry for power transfer, generating mutual inductance between the DIPS coils, namely the near-field transmitting winding 13 (transmitting coil) and / or the far-field positioning signal winding 41, and the power transfer winding 4 (energy coil). Through this magnetic coupling, a voltage is induced in the energy coil 4 during the operation of the DIPS coils 13 and 41, causing current to flow. This current, in turn, establishes a magnetic field that, through superposition, influences the original field of the DIPS coil.

[0053] pass Figure 10 The oscillating circuit with parallel capacitor C2 shown in the diagram for the circuit arrangement of VA produces the same effect. The two sensor windings 9a and 9b, which are part of the positioning device of VA (see, for example...), also produce the same effect. Figure 6 , Figure 7 and Figure 12 Each sensor winding in the array has mutual inductance with the energy coil of VA. Simultaneously, all coils of GA and all coils of VA also form mutual inductance, and vice versa. This results in a matrix with mutual inductance between all the coils.

[0054] According to the present invention, by disconnecting the resonant circuit in GA, the current flow in the GA energy coil caused by the positioning magnetic field is avoided. Similarly, according to the present invention, by disconnecting the resonant circuit in VA, the current flow in the VA energy coil caused by the positioning magnetic field is avoided.

[0055] Figure 13An embodiment of a circuit arrangement 100 according to the present invention for reactive power compensation in an inductive charging device is shown, which is particularly applicable to stationary inductive charging equipment (GA). The circuit arrangement 100 includes two input terminals 101, 102 for connection to a voltage supply unit 150, here a power factor correction (PFC) circuit 151 with a subsequent inverter circuit 152. The circuit arrangement 100 also includes two output terminals 103, 104 for connection to a first energy coil LGA.

[0056] A compensation circuit unit 110 is arranged between the input and output terminals. This compensation circuit unit may be configured differently to include a series capacitor arranged between one input terminal and one output terminal, and / or a parallel capacitor arranged between the two input terminals or the two output terminals. In the illustrated embodiment, the compensation circuit unit 110 has a parallel capacitor C2 arranged between input terminals 101 and 102, a first series capacitor C1a arranged between the first input terminal 101 and the first output terminal 103, and a second series capacitor C1b arranged between the second input terminal 102 and the second output terminal 104.

[0057] Furthermore, according to the present invention, at least one switching unit 120 is provided between an input terminal and an output terminal for disconnecting the electrical connection between the input terminal and the output terminal and interrupting the current flow through the energy coil LGA connected to the output terminal. This / these switching units in Figure 13 The symbols are only symbolically indicated by "X" to specifically show which locations in the circuit arrangement 100 can be provided according to the invention to interrupt the desired interruption of current flow. In principle, a single switching unit is sufficient here, but two or more switching units may also be provided.

[0058] In one configuration, (optionally) additionally, complex impedances jX in the form of series inductors are provided between the input terminals 101 and 102 of the inverter circuit 152 and the circuit device 100. GA / 2. In this configuration, a switching unit can also be arranged in series with such a complex impedance, wherein the switching unit should disconnect the current path via the parallel capacitor C2 and is therefore preferably located after C2, such as Figure 13 As shown in the image.

[0059] If the inverter circuit 152 is controlled so that no current flows through the loop containing capacitors C1a, C1b and energy coil LGA, then alternative or additional ground can also be arranged in other locations, such as in the current path containing capacitor C2. Figure 13(Drawn in dashed line) Switching unit 121. This operation of inverter circuit 152 is also preferred when the compensation circuit does not have a parallel capacitor C2.

[0060] Figure 14 Another embodiment of a circuit arrangement 200 according to the invention for reactive power compensation in an inductive charging device is shown, which is particularly applicable to mobile inductive charging devices (VA). The circuit arrangement 200 includes two input terminals 201, 202 for connection to a voltage acquisition unit 250, here a battery 251 with a pre-amplified rectifier circuit 252. The circuit arrangement 200 also includes two output terminals 203, 204 for connection to a second energy coil LVA.

[0061] A compensation circuit unit 210 is arranged between the input and output terminals. This compensation circuit unit can be configured differently to include a series capacitor arranged between one input terminal and one output terminal and / or a parallel capacitor arranged between the two input terminals or the two output terminals. In the illustrated embodiment, the compensation circuit unit 210 has a parallel capacitor C2 arranged between input terminals 201 and 202, a first series capacitor C1a arranged between the first input terminal 201 and the first output terminal 203, and a second series capacitor C1b arranged between the second input terminal 202 and the second output terminal 204.

[0062] Furthermore, according to the present invention, at least one switching unit 220 is provided between an input terminal and an output terminal for disconnecting the electrical connection between the input terminal and the output terminal and interrupting the current flow through the energy coil LVA connected to the output terminal. These switching units are used in… Figure 14 The symbols are only symbolically indicated by "X" to specifically show which locations in the circuit device 200 can be provided according to the invention to interrupt the desired current flow. In principle, a single switching unit is sufficient here, but two or more switching units may also be provided.

[0063] In one configuration, (optionally) additionally, complex impedances jX in the form of series inductors are provided between the input terminals 201 and 202 of the rectifier circuit 252 and the circuit device 200. VA / 2. In this configuration, the switching unit can also be arranged in series with such a complex impedance. Similarly, the switching unit should disconnect the current path via the parallel capacitor C2, and is therefore preferably located before C2, as shown below. Figure 14 As shown in the image.

[0064] Switching units can be implemented in different ways. Figures 15 to 22Some exemplary configurations of switching units (also known as "break-off circuits") using MOSFETs are shown. Here, n-channel MOSFETs are depicted. They are latched and only turn on when a control signal exceeding their threshold voltage is received at their gate. However, it is also conceivable to implement this using self-turning p-channel MOSFETs.

[0065] Figure 15 A first embodiment of the switching unit in the form of a MOSFET 301 is shown. The body diode of the Si-MOSFET becomes conductable only from an applied voltage of approximately 0.7V. This is also a possible implementation if the voltage drop induced on the MOSFET by the induced current in the corresponding energy coil does not exceed 0.7V.

[0066] Since there are no high voltage withstand requirements for MOSFETs, the switching unit can be constructed using Si-MOSFETs, such as... Figure 16 The embodiment 302 shown uses two Si-MOSFETs connected in anti-series configuration. During power transfer operation, the MOSFETs should be permanently turned on, such that the voltage drop across them is solely due to their on-resistance. For high-current MOSFETs, this is typically in the single-digit milliohm range. The induced voltage during positioning operation is also relatively small (e.g., in the millivolt range). During power transfer operation, the circuit is manipulated such that it forms a short circuit except for the on-resistance of the two MOSFETs, thus having no significant impact on power transfer operation. During positioning operation, the MOSFETs are manipulated such that they operate in blocking mode, thereby preventing current flow through the GA.

[0067] To optimize heat dissipation, multiple parallel MOSFET paths can also be used, such as in... Figure 17 This is illustrated in embodiment 303. Here, the circuit extends, for example, by a parallel path, which ensures that current can be distributed across the various paths and that the individual MOSFETs do not overheat. This allows for even higher current-carrying capacity, which may be advantageous depending on the compensation topology.

[0068] If instead of using Si-MOSFETs, but rather, for example, like Figure 18 If a SiC-MOSFET is used as shown in embodiment 304, a dedicated diode, such as a Schottky diode, should be used due to the high forward voltage (approximately 4.2V) of the body diode.

[0069] In addition to MOSFETs, other components can also be envisioned as switching units, such as... Figure 19The three-terminal bidirectional thyristor switching element 305 or the anti-parallel connected thyristor 306 shown are controlled accordingly. Figure 20 The relay 307 shown can also be conceived as a switching unit.

[0070] Figure 21 An embodiment of the circuit device 100 according to the invention, with a parallel capacitor Cp and a series capacitor Cs, is shown, wherein the switching unit 120 passes through... Figure 16 The implementation method 302 shown is implemented. Figure 22 An embodiment of the circuit arrangement 100 according to the invention is shown, with a parallel capacitor Cp and a series capacitor Cs, wherein the switching unit 120 is implemented by two anti-series connected MOSFETs.

[0071] In principle, there are different topologies for implementing reactive power compensation. For example, in... Figure 13 As shown, a variable inductor jXGA, a parallel capacitor C2, and two series capacitors C1a and C1b can be used. C1a and C1b can also be combined into a single capacitor. Simplified circuits with only a single parallel or single series capacitor can also be constructed. Furthermore, various combinations of series and parallel capacitors and inductors are conceivable for achieving reactive power compensation.

[0072] Figure 23 An embodiment of the circuit arrangement 100 according to the invention is shown, wherein the compensation circuit unit 110 is configured without the parallel capacitor C2, so that the resonant circuit consists only of a series capacitor and an energy coil. In this case, instead of a separate switching unit, the resonant circuit can be disconnected during positioning operation by appropriately manipulating the inverter 152, in particular the four MOSFETs, thereby preventing current flow. Figure 23 In this configuration, inverter 152 is constructed as a full-bridge, but it can also be composed of a half-bridge. The objective here is also to interrupt the current flow in the resonant circuits of the corresponding energy coils LGA and LVA by breaking the circuit.

[0073] In principle, compensation circuit units with other capacitor arrangements can also be envisioned. C1a and C1b can be combined into a single capacitor. Series and / or parallel capacitors can also be omitted. In the case of omitting the parallel capacitor, the resonant circuit can also be disconnected during positioning operation by appropriately manipulating the inverter (e.g., via the optional converter control unit 160).

[0074] Figure 24An embodiment of the circuit device 200 according to the invention is shown, wherein the compensation circuit unit 210 is configured without a parallel capacitor C2, so that the resonant circuit consists only of a series capacitor and an energy coil. The same variations as described above with respect to the circuit device 100 can also be applied to the configuration of the compensation circuit unit 210 of the circuit device 100. For example... Figure 24 The pure series resonant circuit shown can be disconnected by appropriately manipulating the inverter 252 (in this case, an active rectifier), for example, via the optional converter control unit 260.

[0075] Without the parallel capacitor C2, the resonant circuit consists only of a series capacitor and an energy coil. In this case, instead of a separate switching unit, the resonant circuit can be disconnected during positioning operation by appropriately manipulating the rectifier, particularly the four MOSFETs, thereby preventing current flow. With the use of a passive rectifier (diodes instead of MOSFETs), successful disconnection may not be possible; therefore, a switching unit / breaking circuit is still preferred.

[0076] In this application, current-carrying capacity is crucial for MOSFET design, and a solution utilizing Si-MOSFETs without a dedicated diode can also be envisioned. Since the MOSFET is permanently turned on during power transfer operation, the voltage drop across it is determined solely by its on-resistance, which is in the milliohm range and therefore negligible compared to the voltage drop across compensation parameters.

[0077] Figure 25 An embodiment of the circuit arrangement 100 according to the invention is shown, wherein a MOSFET is controlled by a control unit 170 based on a control signal. This control presupposes the identification of an operating mode (power transfer or positioning), for example on an external circuit board, or the operating mode is known. This identification can be performed, for example, by a detection unit 180, such as a positioning-GA-controller board. The control signal can be used to release the voltage supply for controlling the MOSFET. In power transfer operation, it must be ensured that the MOSFET is permanently turned on, which can be ensured, for example, by isolated control with a sufficient gate voltage.

[0078] Figure 26An embodiment of the circuit arrangement according to the invention is shown, wherein the MOSFET is controlled by a control unit 170 based on a control signal. In this embodiment, no external control signal is required to identify the operating mode. For example, the voltage on the MOSFET is measured by a voltage sensor 190. If the voltage exceeds a defined threshold (box 191), power transfer operation is present, thereby closing the switching unit 120 (“On (EIN)”) so that current can continue to flow. If the voltage is below the threshold (box 192), positioning operation is present, thereby opening the switching unit 120 (“Off (AUS)”) so that no current can continue to flow.

[0079] Figure 27 An embodiment of an energy coil 4 constructed from two parallel extending energy coil windings 4a and 4b is shown. This structure is particularly suitable for energy coils of GA, but can also be used for energy coils of VA. Figure 28 An embodiment of the circuit arrangement 100 according to the invention for this implementation of the energy coil is shown. Here, a separate compensation circuit unit is provided for each energy coil winding, each having two series capacitors C1a1, C1b1 or C1a2, C1b2 connected to a common parallel capacitor C2. The potential location of the switching unit in this embodiment is marked with an "X".

[0080] Figure 29 Another embodiment of a circuit arrangement 200 with an energy coil LVA connected to the secondary side of an active rectifier 251 in series compensation is shown. In this case, by appropriately manipulating the active rectifier 251, features such as... can be omitted if necessary. Figure 14 The switching unit shown can disconnect the circuit passing through the VA power coil via the active rectifier 251.

[0081] The invention can be advantageously applied even in embodiments of inductive charging devices that do not have a compensation circuit unit for reactive power compensation. In particular, when the energy coil has two (or more) sub-coils (especially those connected in parallel), the aforementioned problem may occur and lead to undesirable current flow even without such a compensation circuit unit. This current, in turn, establishes a magnetic field that, through superposition, affects the original field of the transmitting coil.

[0082] Figure 30An embodiment of the inductive fixed charging device 1b according to the invention, without a compensation circuit unit for reactive power compensation, is shown. The charging device 1b includes a voltage supply unit 150, a first energy coil (LGA) having at least two sub-coils 4a, 4b, a positioning device 140 for identifying the relative positioning of the energy coils relative to each other (i.e., the first energy coil LGA relative to the second energy coil LVA), and at least one switching unit. The switching units can be arranged in different locations for disconnecting the electrical connection between the voltage supply unit and the first energy coil or between the sub-coils of the first energy coil. This thereby interrupts the current flow through the first energy coil. Reference numerals 122, 123, and 124 indicate the switching units arranged in different locations, wherein one or more of these switching units may be provided.

[0083] Figure 31 An embodiment of the mobile inductive charging device 1a according to the invention, without a compensation circuit unit for reactive power compensation, is shown. The charging device 1b includes a voltage acquisition unit 250, a second energy coil (LVA) having at least two sub-coils 4c, 4d, a positioning device 141 for identifying the relative positioning of the energy coils relative to each other, and at least one switching unit. The switching unit can be arranged in different locations to disconnect the electrical connection between the voltage acquisition unit and the second energy coil or between the sub-coils of the second energy coil. This interrupts the current flow through the second energy coil. Reference numerals 125, 126, and 127 indicate the switching units arranged in different locations, wherein one or more of these switching units can be provided.

[0084] In summary, the present invention provides an effective, economical, and easy-to-implement method for preventing current flow in the energy coil of a corresponding inductive charging device caused by undesirable coupling. According to the invention, neither current measurement nor a corresponding regulation circuit is required for this purpose.

Claims

1. A circuit device for reactive power compensation in an inductive charging device, wherein, The circuit device includes: - Two input terminals for connecting to a voltage supply unit or a voltage acquisition unit; - Two output terminals for connecting either the first energy coil or the second energy coil; - A compensation circuit unit, comprising a series capacitor arranged between one input terminal and one output terminal and / or a parallel capacitor arranged between the two input terminals or the two output terminals; and - At least one switching unit arranged in the compensation circuit unit for disconnecting the electrical connection between the input terminal and the output terminal and interrupting the current flow through the energy coil connected to the output terminal.

2. The circuit device according to claim 1, characterized in that, The compensation circuit unit has a parallel capacitor arranged between the two input terminals or the two output terminals and one or two series capacitors arranged between an input terminal and an output terminal, and / or, the compensation circuit unit has one or two series inductors arranged between an input terminal and an output terminal.

3. The circuit device according to any one of the preceding claims, characterized in that, The at least one switching unit is arranged between an input terminal and an output terminal, particularly in series with the parallel capacitor and / or in series with the series capacitor.

4. The circuit device according to any one of the preceding claims, characterized in that, The at least one switching unit has at least: - Transistors, especially at least one MOSFET, Si-MOSFET, or SiC-MOSFET. - Relay, - Three-terminal bidirectional thyristor switching element, or - Thyristor.

5. The circuit device according to any one of the preceding claims, characterized in that, The at least one switching unit has two anti-series MOSFETs connected in series, particularly Si-MOSFETs or SiC-MOSFETs, wherein each has a diode connected in parallel with the corresponding MOSFET, and / or The at least one switching unit has two MOSFET circuits connected in parallel, each of the MOSFET circuits having two anti-series MOSFETs connected in series, especially Si-MOSFETs or SiC-MOSFETs, wherein each has a diode connected in parallel with the corresponding MOSFET.

6. The circuit device according to any one of the preceding claims, The circuit device also has a control unit for controlling the at least one switching unit such that the at least one switching unit is closed when the energy coil connected to the output terminal is in energy transmission operation where it inductively transmits or receives energy, and in particular, the at least one switching unit is closed only when the energy coil connected to the output terminal is in energy transmission operation.

7. The circuit device according to claim 6, characterized in that, The control unit is configured to acquire and / or determine operational information, including information about whether the energy coil is in the energy transfer operation. In particular, the control unit has a voltage sensor for determining the operating information by measuring the voltage on the at least one switching unit.

8. The circuit device according to any one of claims 6 to 7, characterized in that, The control unit has a voltage supply unit and a gate drive unit for manipulating the gate of at least one transistor.

9. An inductive charging device, comprising: - A circuit device according to any one of the preceding claims; - A voltage supply unit or voltage acquisition unit connected to the two input terminals of the circuit device; - A first energy coil or a second energy coil connected to the two output terminals of the circuit device; as well as - A positioning device for identifying the relative positioning of the energy coils with respect to each other.

10. The inductive charging device according to claim 9, characterized in that, The inductive charging device is a fixed inductive charging device for installation on and / or in the ground, and the positioning device has at least one transmitting coil and / or positioning signal coil for generating a positioning magnetic field, especially for generating a positioning magnetic field during positioning operation, or The inductive charging device is a mobile inductive charging device for installation on and / or in a vehicle, and the positioning device has at least one receiving coil for detecting the positioning magnetic field, especially during positioning operation.

11. The inductive charging device according to any one of claims 9 to 10, characterized in that, The circuit device has a control unit for controlling the at least one switching unit such that when the positioning device is in positioning operation that identifies the relative positioning of the energy coils with respect to each other and when the energy coils are not in energy transmission operation that inductively transmits energy, the at least one switching unit is disconnected.

12. The inductive charging device according to any one of claims 9 to 11, characterized in that, The voltage supply unit or the voltage acquisition unit respectively has a converter unit and a converter control unit, wherein the converter control unit is configured to interrupt the current flow through the energy coil connected to the output terminal, especially when the positioning device is in positioning operation that identifies the relative positioning of the energy coils with respect to each other and the energy coils are not in energy transmission operation that inductively transmits energy.

13. The inductive charging device according to any one of claims 9 to 12, characterized in that, The first energy coil and / or the second energy coil have at least two sub-coils, and each sub-coil is connected to the output terminal of a separate circuit device for reactive power compensation.

14. An inductive charging device, comprising: - i) a voltage supply unit and a first energy coil having at least two sub-coils, or ii) a voltage acquisition unit and a second energy coil having at least two sub-coils; - A positioning device for identifying the relative positioning of the energy coils with respect to each other; as well as - At least one switching unit for disconnecting i) the electrical connection between the voltage supply unit and the first energy coil or ii) the electrical connection between the voltage acquisition unit and the second energy coil or iii) the electrical connection between the sub-coils of the first energy coil or the sub-coils of the second energy coil, and for interrupting the current flow through the first energy coil or the second energy coil.

15. A system for performing inductive energy transfer, comprising the inductive charging device according to claim 13 and the inductive charging device according to claim 14.

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