Resonant circuit of a non-contact energy transfer system for charging an electric vehicle and non-contact energy transfer system for charging an electric vehicle

Abstract

A resonant circuit (500) of a non-contact energy transfer system for charging an electric vehicle and a non-contact energy transfer system for charging an electric vehicle are involved according to the illustrative embodiments of the present invention. According to an embodiment, the resonant circuit (500) includes a first terminal (A4), a second terminal (A3), a plurality of windings, a plurality of capacitors, a first switching element (540) and a second switching element (550). The resonant circuit (500) can be connected to a power supply circuit or a rectifier via the first terminal (A4) and the second terminal (A3). The plurality of windings are divided into a first group of windings (522) and a second group of windings (532), wherein one winding in each group of windings (522, 532) is paired with at least one corresponding capacitor (C3, C4, C5) in the plurality of capacitors, and the capacitors are connected in series to the groups of the paired windings (522, 532). In addition, a connection node (560) is arranged between the first group of windings (522) and the second group of windings (532), the connection node is connected to the first terminal (A4) via the first switching element (540) and is connected to the second terminal (A3) via the first group of windings (522), and the second switching element (550) is arranged between the second group of windings (532) and the first terminal (A4). The first connection node (560) is formed in a star shape among the first group of windings (522), the second group of windings (532) and the first switching element (540).

Description

Field of the Invention

[0001] The present invention relates to a resonant circuit of a contactless energy transfer system for charging an electric vehicle, in particular for charging a drive battery or a traction battery of an electric vehicle, and to a contactless energy transfer system for charging an electric vehicle. Background Art

[0002] Due to the increasing share of electricity generated from renewable energy sources and far-reaching international treaties for reducing greenhouse gases, electric motor vehicles, i.e., motor vehicles with an electric drive, are becoming increasingly important. Electric vehicles are examples of electric motor vehicles, which also include passenger vehicles and freight vehicles (such as subway trains, bicycles with an electric drive, etc.). Generally, an electric vehicle is understood to be a motor vehicle for carrying passengers with at least four wheels, at least four wheels being driven by an electric motor, as a so-called electric drive, and storing the electrical energy required for its movement in a traction battery composed of a number of interconnected battery cells or cell blocks. Since these vehicles do not emit relevant pollutants during operation itself, they are classified as emission-free vehicles compared to fuel-driven vehicles.

[0003] Although an electronically controlled electric motor already delivers maximum torque in a stationary state, and thus, unlike a drive device using an internal combustion engine, generally does not require a manual transmission, and compared to an internal combustion engine, the electric motor is quieter and has little vibration during operation and does not directly emit harmful exhaust gases, the relatively underdeveloped and non-uniformly regulated charging infrastructure and the resulting low level of flexibility of electric vehicle users in autonomously managing longer trips represent obstacles to market acceptance.

[0004] Another significant difference between electric vehicles and fuel-driven vehicles is the comparison of the charging time for replenishing the energy storage with the refueling time. For example, the current refueling time of a few minutes compared to the dozens of minutes for charging the drive battery or traction battery of an electric vehicle (for 80% battery charging at a high-performance DC charging station, currently about 30 minutes).

[0005] However, although all charging systems are based on one standard for charging an electric vehicle, there are indeed different types of charging plugs specifically created for electric vehicles. As a result, there are currently different charging options available, which, however, strongly depend on the manufacturer and the model.

[0006] Compared with fuel-powered vehicles, it may be advantageous to locate "electric filling stations" or charging stations advantageously at locations that accommodate many vehicles (even when not in use), such as garages or permanently allocated parking spaces or company parking lots for company vehicles. Although almost all electric vehicles can be charged at any normal household socket, a standard single-phase household plug connected to a typical 16A fuse in the home allows a maximum transmission of 3.6kW (16A * 230v = 3680W), making it usually take several hours to charge an electric vehicle with a household socket. In addition, when charging at a household socket, it has also been observed that other power-consuming devices may already be connected to the circuit in the household socket circuit, imposing limitations on the continuous load on the main power supply of the household socket used to charge the electric vehicle, especially for several hours continuously.

[0007] It does not seem unreasonable to assume that the increasing acceptance of electric vehicles is particularly related to the increase in electrification, and that improvements in user convenience for electric vehicles will have a significant impact.

[0008] An improved method provides, for example, contactless charging without open contacts, where energy is transmitted non-contactingly to the vehicle by induction when driving or parking, for charging the rechargeable battery on the electric vehicle. Since the user's handling of the plug and charging cable is eliminated, an opportunity for increased market acceptance arises.

[0009] A contactless charging system for an electric vehicle generally includes a primary resonator device configured to output electrical energy and a secondary resonator device configured to receive the electrical energy output from the primary resonator device.

[0010] In the case of wireless energy transfer, there are basically two physically different principles: First, wireless energy transfer in the near field, also known as non-radiative coupling. This includes, for example, inductive coupling based on the magnetic flux generated in the primary resonator device and detected by the secondary resonator device. Second, energy transfer in the far field, also known as radiative energy transfer, which is based on electromagnetic waves.

[0011] Wireless energy transfer in the near field (first see above) is limited in terms of the range of energy transfer to a distance close compared to the wavelength of the energy transfer radiation.

[0012] Energy transfer in the far field is limited to relatively low-output transfers because the so-called free space path loss (i.e., the power density of the electromagnetic wave propagating in free space decreases without interference from additional damping media or reflections) only allows a very low efficiency level of less than 1%.

[0013] Therefore, for the non-contact charging of electric vehicles, current charging systems mainly face the near-field transmission of electromagnetic energy through inductive coupling, where the primary coil or transmitting coil is embedded in the ground, such as a road surface or a parking lot, and the secondary coil or receiving coil is attached to the electric vehicle, such as attached to the bottom of the vehicle body. In the private domain, installation above the ground is also possible, where the primary coil or transmitting coil at least partially protrudes from the ground.

[0014] The following will describe known coil configurations for the primary coil and / or secondary coil with reference to FIGS. 1a, 1b, and 1c.

[0015] FIG. 1a schematically shows a top view of a coil 1a having a so-called "double D coil design". According to the illustrated configuration, the winding 5a is disposed here on the magnetic core 3a. In particular, the individual turns of the winding 5a do not surround the magnetic core 3a.

[0016] FIG. 1b schematically shows a coil 1b having a so-called "solenoid coil design", according to which the winding 5b is arranged on the magnetic core 3b such that the individual turns of the winding 5b surround the magnetic core 3b.

[0017] For example, a device for wireless charging of an electric vehicle is described in document WO2016 / 114893A1.

[0018] A non-contact energy transmission device is known from document DE102017205215A1.

[0019] In view of the improvement in electrification, generally, the object of the present invention is to provide a specific coil design for inductively charging an electric vehicle (such as an electric car). Wherein improved output power (e.g., higher than 7 kW) can be transmitted at an improved efficiency level while maintaining a compact design. In addition, an object is to provide a coil design that at least reduces self-heating due to heat dissipation losses.

[0020] In the development of charging systems, framework conditions regarding other aspects are usually adhered to, such as available installation space, predetermined minimum efficiency, predetermined minimum transmission power, predetermined minimum electric intensity, requirements in terms of stability, etc.

[0021] FIG. 1c schematically shows a known system 10 for non-contact charging of an electric vehicle. The system 10 includes a primary resonator device 13 with a winding 14 on the ground side and a secondary resonator device 15 on the vehicle side. The winding 14 is formed according to the double D configuration shown in FIG. 1a. The Cartesian coordinate system x, y, z represents the orientation in space.

[0022] In a known system, a power of 10 kW needs to be transmitted in order to obtain sufficient charging power for driving a battery or a traction battery. However, the optimal energy transfer occurs only under the optimal arrangement of the secondary resonator device 15 relative to the primary resonator device 13 on the ground side. The optimal arrangement of the secondary resonator device 15 relative to the primary resonator device 13 cannot generally be ensured because the arrangement of the secondary resonator device 15 depends on the parking position of the electric vehicle relative to the primary resonator device 15. The offset of the secondary resonator device 15 from its optimal arrangement position in the current parked position is generally assumed to be, for example, an offset vx along the x direction and / or an offset vy along the y direction. The offset vx and / or the offset vy from the optimal arrangement of the secondary resonator device 15 for the primary resonator device 13 on the ground side results in less coupling between the primary resonator device 13 and the secondary resonator device 15, thereby affecting the efficiency of energy transfer.

[0023] The system 10 can further have an offset vz depending on the vehicle class of the electric vehicle to be charged, because the relative height between the primary resonator device 13 and the secondary resonator device 15 (i.e., the distance along the z direction) depends on the vehicle class of the electric vehicle. The system 10 is designed for a specific height between the primary resonator device 13 and the secondary resonator device 15, i.e., the operating frequency of the system 10 at a specific height between the primary resonator device 13 and the secondary resonator device 15 (i.e., the operating frequency of the system 10 for non-contact charging of the electric vehicle) is equal to the resonance frequency of the arrangement of the primary resonator device 13 and the secondary resonator device 15. If the electric vehicle is now charged with the secondary resonator device 15 on the vehicle side arranged with an offset vz relative to the specific height at which resonance means optimal energy transfer, the system 10 does not resonate at the operating frequency.

[0024] The object of the present invention is to design a system that can also operate resonantly and with good efficiency while having an offset. Different load requirements must be observed so that the resonators, inductors, and capacitors used do not overheat and the energy source is not overloaded.

[0025] Figure 1d shows a schematic circuit diagram of the system 10 of Figure 1c. The primary resonator device 13 here includes an input filter 13a having inductors L1, L2, and a capacitor C1 connected in series, and a primary resonator 13b having an inductor L3 and a compensation capacitor C2. The secondary resonator device 15 includes a secondary resonator 15a having an inductor L4 and a compensation capacitor C3 connected in series, a rectifier 15b having diodes D1 to D4, and a drive battery 15c of an electric vehicle to be charged (not shown), and the drive battery 15c is represented by a battery resistance R1 and a battery capacitance C4. Coupling to a power supply (not shown) is provided at the input filter.

[0026] Figure 1e shows a simplified equivalent circuit diagram of the circuit diagram of Figure 1d. In the simplified equivalent circuit diagram of Figure 1e, the inductive coupling between the main resonator device 13 and the secondary resonator device 15 is shown by the coupled resonator circuit 13c, where the mutual inductance M shows the coupling. In particular, the mutual inductance M is proportional to the coupling k between the main resonator device 13 and the secondary resonator device 15. The total impedance derived from the equivalent circuit diagram of Figure 1d is proportional to M 2 indirectly. Assuming that the inductances L3 - M and L4 - M in Figure 1e are approximately independent of the coupling k, the ratio between the mutual inductance M and the coupling k can be assumed. Therefore, the total impedance derived from the equivalent circuit diagram in Figure 1e is also proportional to k 2 indirectly. This in turn means that, for the same power consumption, the current drawn from the energy supply (not shown) increases. The ratio of current to voltage depends strongly on the coupling; in particular, for low coupling, a large input voltage is required for the system 10 in Figure 1c, and a very large current is generated with large coupling. Since the total impedance of the system 10 in Figure 1c is proportional to the effective inductance of the input filter 13a, a large total impedance is introduced through the input filter 13a, thereby causing current limitation, which is advantageous when the coupling is large.

[0027] Since the ratio of the heat dissipation loss in the input filter 13a to the output power of the resonator is proportional to M 2 (i.e., proportional to k 2 ), the ratio of the power loss in the input filter 13a to the output power increases significantly when the coupling is large. To achieve the desired output power, a very large input current is required, which also causes a serious loss in efficiency.

[0028] As a result, the change in the mutual inductance M of the system 10 in Figure 1c has a very strong effect on the required input voltage of the system 10 in Figure 1c. When there is an offset, there is a large variance in the mutual inductance, as will now be seen in Figure 1f.

[0029] Figure 1f graphically represents the results of comparative measurements carried out by the inventors. The left vertical axis represents the dependence of the inductances of the main and secondary resonators on the coupling k with respect to the reference vertical axis. Referring to the right vertical axis in Figure 1f, the dependence of the mutual inductance M on the coupling k is shown. As a result, the mutual inductance M varies over a wide range as the coupling k changes. Therefore, if the system 10 in Figure 1d is to operate effectively simultaneously, it is not possible to cover the entire operating range in the system 10 of Figure 1c due to the strong variation of the mutual inductance M. SUMMARY OF THE INVENTION

[0030] In view of the above description, an object is to compensate for possible offsets without sacrificing the energy transfer efficiency, without making major changes to the circuit structure.

[0031] Within the scope of the present invention, the above problems and objectives are met by a resonant circuit of a contactless energy transfer system for charging an electric vehicle according to claim 1 (wherein further more advantageous developments thereof are defined in dependent claims 2 to 11) and by a contactless energy transfer system for charging an electric vehicle according to claim 12 (wherein further more advantageous developments thereof are defined in dependent claims 13 - 15).

[0032] In a first aspect, the present invention provides a resonant circuit of a contactless energy transfer system for charging an electric vehicle. In a schematic embodiment, the resonant circuit includes a first terminal and a second terminal, a plurality of windings, a plurality of capacitors, a first switching element, and a second switching element. The resonant circuit can be connected to a power supply circuit or a rectifier via the first terminal and the second terminal. Thus, when the resonant circuit is connected to a power supply circuit that supplies energy to the contactless energy transfer system, the resonant circuit can be used in the main resonator device such that energy can be transferred non - contactlessly from the main resonator device to the secondary resonator device, or when the resonant circuit is connected to a load, the resonant circuit can be used in the secondary resonator device, where the load represents at least one battery device to be charged by the contactless energy transfer system, in particular the drive battery or traction battery of the electric vehicle to be charged.

[0033] The plurality of windings are divided into a first group of windings and a second group of windings. According to some schematic embodiments herein, at least one capacitor in series connection with the associated group of windings among the plurality of capacitors can thus be associated with each group of windings. The resonance of the resonant circuit can be set to a specific resonance frequency by the capacitors associated with each group, wherein each capacitor having an associated group of windings sets a specific resonance frequency associated with that group.

[0034] Furthermore, the first connection node is arranged between the first set of windings and the second set of windings and is correspondingly arranged between two of the first set of windings, the second set of windings, and the first switching element, and is connected to the first terminal via the first set of windings such that the first connection node is formed in a star configuration. Each of the first set of windings, the second set of windings, and the first switching element can be directly connected to the first connection node here, in particular without other elements between each of the first set of windings, the second set of windings, and the first switching element and the first connection node. The first and second switching elements enable the first and second sets of windings to be disconnected. For example, the first and second sets of windings can be disconnected, or the windings of the second set can be removed from the series connection of the first and second sets of windings. The windings of the second set continue to be connected to the circuit at the first connection point such that the second set of windings has a defined electrical potential and damage caused by a potential difference can be prevented even though it is disconnected by the second switching element being opened. In the illustrative example here, the first set of windings and the second set of windings can be directly connected to the first connection node, where no other elements are arranged between the first connection nodes of each set of windings such that a defined electrical potential is always applied to each set of windings. In an illustrative embodiment, each set of windings can be arranged between an associated capacitor and the first connection node.

[0035] In some illustrative embodiments of the first aspect, the resonant circuit can further include a third set of windings and a third switching element connected in series therewith, where the third set of windings and the third switching element connected in series therewith are connected in parallel to the first connection node with the second set of windings. The series connection consisting of the third set of windings and the third switching element allows for further adjustment options of the resonant circuit. According to the illustrative embodiment, the first connection node is formed in a star configuration and has at least three pins or rays. Each set of windings can be directly connected to the first connection node here, in particular without other elements between the first connection node and each set of windings.

[0036] In some illustrative embodiments of the first aspect, a second connection node can be arranged between the first switching element and the second switching element, and the corresponding first switching element and the second switching element are connected to the first terminal through the second connection node, wherein the second connection node is formed in a star shape between the first switching element, the second switching element and the first terminal. The resonant circuit can further include another circuit segment having a fourth set of windings and a fourth switching element connected in series therewith, wherein the other circuit segment is connected in parallel with the second set of windings to the second connection node. In addition, the second connection node can also be formed in a star shape between the first switching element, the second switching element and the first terminal, and the circuit segment between the first connection node and the second connection node can be connected in parallel with the second set and the first switching element connected in series therewith. The second connection node is herein set as the common low end of the group of windings for parallel connection, and when the group of windings connected in parallel is connected to the first terminal, the second connection node can be selectively isolated from the second set of windings through the second switching element. According to the illustrative embodiment, the second connection node is formed in a star shape and has at least three pins or rays. Each set of windings can be connected to the second connection node only via a switching element arranged therebetween. In particular, an associated one of the switching elements is arranged between the second connection node and each set of windings. In some illustrative examples herein, the second switching element can be arranged between the second connection node and the second set of windings, wherein the first switching element is arranged between the first connection node and the second connection node, such that the first switching element is connected in parallel with the second set of windings and the second switching element. In other words, the first switching element is arranged in the first circuit segment between the first connection node and the second connection node, while the second set of windings and the second switching element are arranged in the second circuit part connected in parallel with the first circuit segment. Both the first and second circuit segments are connected in series with the first set of windings and the first connection node.

[0037] In some illustrative embodiments of the first aspect, the two switching elements can be configured such that as long as the first switching element is closed, the second switching element is open, and the second switching element is closed only when the first switching element is open. According to this configuration, an advantageous operating mode is achieved, according to which the turns of the second set of windings can be selectively switched on or off, such that the number of turns of the resonant circuit can be switched between the number of turns of the first set or the total number of turns of a plurality of windings.

[0038] In some illustrative embodiments of the first aspect, a plurality of windings can be provided as a hybrid double-D solenoid coil on a plate-shaped ferrite core. In this case, the coil structure based on the hybrid double-D solenoid coil allows for a relatively large coupling for a relatively large distance and / or offset between the main resonator device and the secondary resonator device relative to each other.

[0039] In some illustrative embodiments of the first aspect, the first set of windings can be formed by encapsulating two electrically identical windings connected in parallel. In the electrically identical winding encapsulation, the current values and voltage values of the windings encapsulated in parallel are the same, preventing the balancing current between the windings encapsulated in parallel. By using the windings encapsulated in parallel, the current-carrying capacity of the first winding encapsulation can be increased.

[0040] In some illustrative embodiments of the first aspect, the second set of windings can be formed by encapsulating two electrically identical windings connected in parallel. Using the windings encapsulated in parallel allows the induced voltage in the unused turns of the cut-off windings of the second set of windings to be partially or completely eliminated. Using the windings encapsulated in parallel can also increase the current-carrying capacity of the second set of windings.

[0041] In some illustrative embodiments of the first aspect, the first set of windings can have a first number of turns in the range from 5 to 20 turns, and the second set of windings can have a second number of turns in the range from 1 to 10 turns, where the first number of turns is greater than the second number of turns. This enables the compact resonant circuit to have favorable energy transfer efficiency.

[0042] In a second aspect, a non-contact energy transfer system for charging an electric vehicle is provided with a primary resonator device and a secondary resonator device, where at least one of the primary resonator device and the secondary resonator device includes a resonant circuit, and the resonant circuit is the resonant circuit according to the first aspect.

[0043] In some illustrative embodiments of the second aspect, the second set of windings can be formed by encapsulating two electrically identical windings connected in parallel, and each winding encapsulation of the parallel connection of the second set of windings can be connected in series with an associated additional capacitor. Further, the additional capacitors associated with the winding encapsulations of the second set of windings can be configured such that the interconnection of the parallel winding encapsulations of the second set with the associated additional capacitors has a resonance frequency greater than the operating frequency of the contactless energy transfer system, while the resonance frequency of the resonance circuit for the series connection of the first set of windings and the second set of windings with the associated capacitors has a resonance frequency substantially equal to the operating frequency of the contactless energy transfer system. Thus, what is achieved is that the impedance of the cut-off turns of the second set of windings is high and the balancing current is suppressed. Further, when the second switching element is open, the parallel connection of the winding encapsulations of the second set of windings becomes a series connection in which the winding encapsulations of the second set of windings are switched to be anti-parallel to each other. This ensures that the voltages induced in the turns of the second set of windings cancel each other out. In each operating mode of the resonance circuit, it is achieved that the resonance circuit remains in resonance at the operating frequency of the contactless energy transfer system. For example, the operating frequency of the contactless energy transfer system can be in the range of 80 kHz to 90 kHz, where good energy transfer efficiency can be obtained. According to a further example, the resonance frequency of the interconnection of the parallel winding encapsulations of the second set with the associated additional capacitors can be greater than 90 kHz, such that the resonance frequency of the interconnection of the parallel winding encapsulations of the second set with the associated additional capacitors is sufficiently far from the operating frequency of the contactless energy transfer system.

[0044] In the illustrative embodiments of the second aspect described above, the resonance circuit can be configured as the main resonator device and / or the secondary resonator device in the contactless energy transfer system, thereby providing an advantageous main charging system and / or secondary charging system for charging the traction battery of an electric vehicle.

[0045] In the above aspects, the mutual inductance is adjusted while not changing or substantially not changing the resonance behavior (especially its resonance frequency) of the resonance circuit. Regardless of the switching configuration of the switching elements, the windings remain magnetic in the system.

[0046] In the embodiments presented above and below, the connection nodes represent defined nodes where multiple lines are connected. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Other advantages and illustrative embodiments of the aspects of the present invention described above are described below with reference to the accompanying drawings, in which:

[0048] FIGS. 1a to 1b schematically show known coil designs;

[0049] FIG. 1c schematically shows a known system for contactless charging of an electric vehicle;

[0050] FIG. 1d schematically shows a circuit diagram of the system for non-contact charging of an electric vehicle in FIG. 1c;

[0051] FIG. 1e shows a simplified equivalent circuit diagram of the circuit diagram in FIG. 1d;

[0052] FIG. 1f graphically shows the results of comparative measurements;

[0053] Figure 2 Schematically shows a coil according to the so-called "hybrid double-D solenoid coil design";

[0054] Figure 3a Shows an inductive component for a non-contact charging system according to some schematic embodiments of the present invention;

[0055] Figure 3b Shows Figure 3a a bottom side view of the inductive component in;

[0056] Figure 3c Shows Figure 3a and Figure 3b an inner cross-sectional view of the inductive component shown in;

[0057] Figure 3d Shows a side cross-sectional view of a ferrite core having a winding body for Figures 3a - 3c ;

[0058] Figure 4 Schematically shows a system for non-contact charging of an electric vehicle according to schematic embodiments of the present invention;

[0059] Figure 5 Shows a schematic circuit diagram of a resonant circuit for a non-contact energy transfer system according to schematic embodiments of the present invention;

[0060] Figure 6 Shows a schematic circuit diagram of a resonant circuit for a non-contact energy transfer system according to further schematic embodiments of the present invention; and

[0061] Figure 7 Graphically depicts the relationship between the inductance and coupling of a resonant circuit according to schematic embodiments of the present invention. DETAILED DESCRIPTION

[0062] Figure 2 Schematically shows a coil 1c according to the so-called "hybrid double-D solenoid coil design". The coil design of the shown coil 1c represents a hybrid between a double-D coil design (see the double-D coil design shown in FIG. 1a) and a solenoid coil design (see the solenoid coil design shown in FIG. 1b).

[0063] According to Figure 2 In the schematic diagram of Figure 2 , the coil 1c here includes a winding 5c on the magnetic core 3c, including a turn 5c1 and another turn 5c2, where the turns 5c1 and 5c2 are wound at an angle with respect to the magnetic core 3c. This means that the turn axes of each of the turns 5c1, 5c2 (i.e., the axes perpendicular to the plane in which the turns 5c1 and 5c2 are arranged) deviate from the direction along the thickness d by less than 45° respectively. Compared with the solenoid coil design shown in Fig. 1b, it can be seen that the winding axis of the winding 5b is oriented substantially perpendicular to the direction along the thickness of the magnetic core 3b ( Figure 2 The "d" in Figure 2 is thus also defined for Fig. 1b), in particular, the winding axis of the winding 5b, i.e., the axis perpendicular to the plane of the turns of the winding 5b, is oriented at an angle greater than 45° with respect to the direction along the thickness of the magnetic core 3b.

[0064] Hereinafter, reference will be made to Figures 3a to 3d The inductive component 100 of the system for non-contact charging according to the schematic embodiments of the present invention will be described in detail. The inductive component 100 is formed corresponding to the so-called "hybrid double D - solenoid coil design". The inductive component 100 can represent a schematic embodiment of the non-contact energy transfer system according to the present invention.

[0065] Figure 3a A top view of the upper side of the inductive component 100 is shown. The term "upper side" hereinafter shall refer to the side of the inductive component 100 that is arranged in a direction opposite to the "bottom side" of the inductive component 100, and the "bottom side" is oriented towards another inductive component (not shown) in the system for non-contact charging of an electric vehicle (not shown).

[0066] In a schematic example, the inductive component 100 can be attached to an electric vehicle (not shown). In addition, the inductive component 100 can be attached here such that the upper side is oriented towards the bottom of the vehicle body, while the bottom side is oriented towards the ground (not shown), such as a road surface, a parking lot floor, a garage floor, etc.

[0067] In another schematic example, the inductive component 100 can be arranged on or in the ground (not shown), for example, embedded therein, and the ground such as a road surface, a parking lot floor, a garage floor, etc. The bottom side will be oriented towards the bottom of the vehicle body (not shown) of an electric vehicle (not shown) here.

[0068] The inductive component 100 includes a plate-shaped ferrite magnetic core 110 and a hybrid double D solenoid coil 150 arranged above the plate-shaped ferrite magnetic core 110 and having a plurality of turns 160. The plurality of turns 160 are formed here by multiple turns (i.e., at least four turns). Figure 3a In Figure 3a , a turn is designated by the reference numeral 166 as an example. Thus, the reference numeral "166" represents a single turn among the plurality of turns

[0069] The plurality of turns 160 are combined into a plurality of groups in a manner discussed in more detail below, each group consisting of a number of adjacent consecutive turns.

[0070] As Figure 3a shown, the plate-shaped ferrite core 110 is formed by a number of individual ferrite plates 111, 113, 115, which are joined together to form the plate-shaped ferrite core 110. Alternatively, the plate-shaped ferrite core 110 can be integrally formed, in particular from a single plate-shaped ferrite element, in which case, contrary to Figure 3a that shown, there are no connecting parts in the plate-shaped ferrite core 110.

[0071] According to several exemplary embodiments, as Figure 3a illustrated by way of example, the plate-shaped ferrite core 110 can include a transverse recess 114. For example, the terminals 122, 124 of the inductive component are received in the transverse recess 114 in a space-saving manner, where the transverse dimension of the inductive component remains small. Additionally or alternatively, a capacitive component (not shown), such as at least one capacitor, can be received in the recess 114.

[0072] As Figure 3a illustrated by way of example in, according to an exemplary embodiment, the recess 114 is provided as a tapered section of the ferrite core 110, where the transverse dimension of the ferrite core 110 in the recess 114 is smaller than the transverse dimension of the ferrite core 110 outside the recess 114 with respect to the longitudinal direction of the ferrite core 110, and the longitudinal direction is denoted by the reference sign L in Figure 3a and Figure 3b d. The direction perpendicular to the longitudinal direction L is called the width direction, denoted by the reference sign B in Figure 3a - 2 d.

[0073] According to an exemplary embodiment of the present invention, for the dimensions in the longitudinal direction L and the width direction B, the following can hold: L > B, L ≈ B or L < B.

[0074] The direction perpendicular to the directions L, B is called the thickness direction D in Figure 3c and Figure 2 d. With respect to the thickness direction D, the ferrite core 110 has a dimension smaller than the dimensions along the directions L and B: D < L, B.

[0075] According to specific exemplary embodiments, it holds that: D < L / 10 and / or D < B / 10. According to a preferred embodiment, D < L / 20 and / or D < B / 20. According to the specific present exemplary illustration, it holds that: D < L / 30 and / or D < B / 30. The aspect ratio resulting with respect to D and L, B clearly identifies the ferrite core 110 as a "plate-shaped ferrite core", which is identified as having the direction along the thickness in which the plate-shaped ferrite core has the smallest extension, in the case where recesses such as recess 114 are not taken into account.

[0076] According to an exemplary embodiment, the hybrid double-D solenoid coil 150 includes a first winding 152 and a second winding 154, each winding including a plurality (in particular, two or three or more) turns. In Figure 3a a top view of the upper side of the inductive component 100 shown, the first winding 152 is arranged on an end of the plate-shaped ferrite core 110 opposite to the second winding 154 with respect to the width direction B, or the turn segments of the plurality of turns of the first winding 152 (e.g., Figure 2 turn 166 in a) extend substantially parallel to the longitudinal direction L over at least the largest part of the plate-shaped ferrite core 110. Figure 3a The specific situation is currently shown: the turn segments extend parallel to the longitudinal direction L on the plate-shaped ferrite core 110 of the first winding 152, as long as Figure 3a the turn segments of the first winding 152 directly extend on the plate-shaped ferrite core 110 in the view shown, while the turn segments to the sides of the plate-shaped ferrite core 110 have an arcuate profile and extend towards the bottom side of the inductive component 100 behind the plate-shaped ferrite core 110 with respect to Figure 3a the view shown in. This also applies to the second winding 154. However, this does not constitute any limitation, for example, different orientations of the turn segments can be implemented at an angle to the longitudinal direction L.

[0077] The first winding 152 is electrically and mechanically connected to the terminals 122, 124 of the inductive component via terminal contacts 157, 158, and the terminal contacts 157 and 158 are connected to the multiple turns of the first winding 152 via respective lead segments 163 and 164. The terminal contacts 157, 158 and the terminals 122, 124 can be electrically and mechanically connected to each other in any way, such as by a crimp connection, a threaded connection, a plug connection, a solder connection, etc. Accordingly, the second winding 154 is connected to the terminals 122, 124 via terminal contacts 155, 156, the terminal contact 155 is connected to the multiple turns of the first winding 154 via a lead segment 161, and the terminal contact 156 is connected to the multiple turns of the second winding 154 via a lead segment 162.

[0078] The lead segments 161, 162, 163, 164 extend substantially parallel to the width direction B on the side surface of the plate-shaped ferrite core 110 and are arranged on the inner side according to the schematic embodiment, wherein the lead segments 161, 162, 163, 164 extend along the longitudinal direction L at a distance smaller than the side surface of the plate-shaped ferrite core 110 from the farthest turn segments of the multiple turns of the first winding 152 and the second winding 154. Optionally, the lead segments 161, 162, 163, 164 may be arranged at a distance greater than the outermost turn segments of the multiple turns of the first and second windings 152, 154 from the plate-shaped ferrite core 110, whereby the lead segments 161 - 164 are now set as external lead segments. In the latter case (not shown), the lead segments 161 - 164 are not covered by the turn segments of the multiple turns of the first and second windings 152, 154.

[0079] Reference Figure 3b , and contrary to the top view of the upper side shown in Figure 3a , a top view of the bottom side of the inductance component 100 is shown. When comparing Figure 3a and Figure 3b , it is found that the turn segments of the turns of the first winding 152 and the second winding 154, in Figure 3a and Figure 3b the shown top views, directly extend on the plate-shaped ferrite core 110. In Figure 3a the case of the upper side, since the angular positions of the turns of the first winding 152 and the second winding 154 can be arranged relative to the width direction B, for example, the distance between them is greater than in the case shown in the view of Figure 3b showing the bottom view, where the turn segments of the turns of the first winding 152 and the second winding 154 extend along the width direction B, for example, at a smaller distance compared to Figure 3b , such that the magnetic pole segments 141, 143, 145 of the plate-shaped ferrite core 110 are formed towards one end of the plate-shaped ferrite core 110 in the width direction B, while the magnetic pole segments 147, 148, and 149 are exposed at the opposite end relative to the width direction B. In Figure 3a the top view of the upper side, only the plate-shaped ferrite core 110 is exposed at the connection segments 111, 113, 115 arranged between them, and the connection segments 111, 113, 115 are arranged between the magnetic pole segments 141, 143, 145 and 147, 148, 149 as shown in Figure 3b .

[0080] Reference Figure 3c , shows a side view of the inductance component 100 in Figure 3a and Figure 3b , for example, as seen from Figure 3b as shown in Figure 3bThe inductance component 100 shown is tilted upright out of the plane of the paper shown, such that the terminals 122 are viewed perpendicularly from the side. In Figure 3c the side view shown, the angular positions of the turns of the first and second windings 152, 154 relative to the width direction B, i.e., the normal of the plane formed by the turns of the first winding 152 (as indicated by the schematic winding plane WE relative to the normal represented by n in Figure 3c ) are oriented at an inclined angle relative to the width direction B, where the angle α represents the angle between the normal n and the width direction B. The angle α is not equal to 0°, and according to a specific schematic embodiment, for example, is greater than or equal to 5° (α≥5°), which does not limit the present invention. This also applies to the second winding 154, where the first winding and the second winding may be wound mirror-symmetrically relative to a symmetry axis oriented parallel to the thickness direction D between the first winding and the second winding.

[0081] According to a schematic embodiment, as Figures 3a - 3c shown, the inductance component 100 includes a winding element 130 having a first support element 132 configured to receive and support the first winding 152 and a second support element 134 configured to receive and support the second winding. The support element 132 may have, for example, an elongated plate-like shape that at least partially covers the ferrite core 110 along the longitudinal direction L and is formed of an electrically insulating material (such as by injection molding, etc.).

[0082] Regarding Figure 3d , Figure 3c the plate-like ferrite core 110 shown in Figure 3c , it does not have the terminals 122 and the first and second windings 152 and 154 with terminal contacts. According to Figure 3d the illustration in, only the plate-like ferrite core 110 and the winding element 130 are shown, especially in the side view.

[0083] According to a schematic example of the present invention, as Figure 3dAs schematically shown, the plate-shaped ferrite core 110 includes a first step 171 and a second step 172. According to the step 171, the exposed surface of the magnetic pole segment 141 is arranged to be offset relative to the connecting segment 111 along the thickness direction D, that is, an offset V1 is formed by the step 171 between the surface of the connecting segment 111 in the same orientation and the exposed magnetic pole surface of the magnetic pole segment 141. Thus, the magnetic pole segment 147 is offset relative to the connecting segment 111 by the step 172, and this offset is particularly formed between the exposed magnetic pole surface of the magnetic pole segment 147 and the surface of the connecting segment 111 in the same orientation. This does not limit the present invention, and only one of the steps 171 and 172 may be formed instead of forming both steps 171 and 172. Alternatively, the steps 171 and 172 may be formed such that the offset associated with the step 171 is different from the offset associated with the second step 172.

[0084] According to Figure 3d In the exemplary illustration in, the winding element 130 includes support elements 132, 133, 134, 135, wherein the support elements 133 and 135 are formed adjacent to the corresponding steps 171 and 172 such that they partially cover the connecting segment 111, while the magnetic pole segment 141 or the magnetic pole segment 147 is not covered by the support element 135 or 133, respectively. On the other hand, the support elements 132 and 134 are formed such that the steps 171 and 172 are covered by the support elements 132 and 134 on the upper side of the plate-shaped ferrite core 110.

[0085] The support element 132 includes a plurality of grooves 132n corresponding to the number of turns of the second winding, as Figure 3c shown in. The support element 133 includes a plurality of grooves 133n according to the number of turns of the second winding 154 and corresponding to the number of grooves 132n of the support element 132. This also applies to the support elements 135 and 134 of the first winding 152 shown in Figure 3c .

[0086] The grooves 132n, 133n, 134n, 135n receive the turn segments of the turns on the upper side or the lower side of the plate-shaped ferrite core 110, and insulate the adjacent turn segments from each other along the upper side or the lower side of the plate-shaped ferrite core 110, so as to prevent turn short-circuiting, for example, if the covering material for the turn segments is omitted. In addition, the support elements 132, 133, 134, 135 contribute to the mechanical fixation and stability of the first and second windings 152, 154.

[0087] Figure 3dA schematic embodiment of the winding element 130 is shown, in which some of the grooves of the support elements 133, 135 are less deep or have partition walls of lower height. These schematic embodiments are only used to show the construction options of the support elements 133, 135 in terms of installation space and do not constitute any limitation of the present invention. Alternatively, the grooves of the support element 133 and / or 135 can be as uniform as possible (i.e., having as uniform a depth or as uniform a height of the partition wall as possible, where "as possible" means the admissible deviation from the ideal situation within the manufacturing tolerance, for example, a deviation of about 5% or about 10% from a predetermined dimension).

[0088] Reference will be made to Figure 3c describe the connection configuration of the first winding 152 and the second winding 154 to the terminals 122, 124 of the inductive component 100. In this case, the first winding 152 is electrically connected to the terminals 122, 124 through the terminal contacts 157, 158 (see Figure 3a Regarding the terminal contacts of the first winding 152), and the second winding 154 is electrically connected to the terminals 122, 124 of the inductive component 100 through the terminal contacts 155, 156. When a voltage is applied to the terminals 122, 124 of the inductive component 100 in the first winding 152 and the second winding 154, a current flowing through the first winding 152 is caused during operation according to the turn direction of the first winding 152 in the first rotational direction, while the flow through the second winding 154 is according to the turn direction of the second winding 154 in the second rotational direction, where the first rotational direction and the second rotational direction are oriented in opposite directions to each other. This results in a magnetic field, as shown by the B-field lines BL schematically drawn in Figure 3c . Specifically, the B-field lines BL leave one of the magnetic pole segments 141, 147 and enter the other of the magnetic pole segments 141, 147, as determined by the orientation of the currents in the first and second windings 152, 1�4. In the plate-shaped ferrite core 110, the back iron of the B-field lines BL is located between the magnetic pole segments 141, 147 of the inductive component 100 described according to Figure 3a - 2 d. Therefore, the inductive component 100 exhibits good coupling characteristics to another inductive component (not shown), is insensitive to the lateral offset of the two inductive components relative to each other compared to a coil design according to a known coil design as shown in Fig. 1a, and the inductive component exhibits favorable coupling performance compared to the coil designs in Figs. 1b and 1c.

[0089] Now reference will be made to Figure 4 describe a charging system 300 for non-contact charging of an electric vehicle 312. The system 300 can represent another schematic embodiment of a non-contact energy transfer system according to the present invention.

[0090] According to Figure 4In the illustration, the main resonator devices 302a and 302b with inductive components 304a and 304b on the main side are arranged in the charging system 300, which can be located, for example, in a parking lot or in a garage and embedded in the ground. The main resonator devices 302a and 302b are connected to the power distribution device 330 via respective connection lines 308 and 310. The power distribution device 330 is in turn connected to the power grid via line 332, and they themselves provide the components of the main charging system for charging the electric vehicle 312. The power distribution device 330 may include, for example, a communication unit 334, which can communicate with one or more external control units (not shown). According to some illustrative examples herein, the main resonator device 302a may be provided by the inductive component 100 referred to above Figures 3a - 3d described.

[0091] The energy storage device 318 on the vehicle side is arranged in the electric vehicle 312, for example, a rechargeable battery or a rechargeable system composed of rechargeable batteries, which is connected to the secondary resonator device 316 via a charging controller 314, especially a drive battery or a traction battery. Compared with the energy storage of in-vehicle electronics for electric vehicles operating in a 12 V or 48 V vehicle electrical system, the drive battery in an electric vehicle has a DC voltage of several hundred volts, for example, in the range greater than 3**0 V, such that the requirements for the energy storage device 318 and the performance of the energy storage device 318 are many times higher than those of other energy storage devices.

[0092] The secondary resonator device 316 may include, for example, a housing 317, in which an inductive component is accommodated, as described above with reference to Figures 3a - 3b (compare inductive components 100; 200), which may be arranged as an element of the secondary charging system for charging the electric vehicle 312. The housing 317 may be formed, for example, on the lower part of the body of the electric vehicle 312 for mechanical mounting on the electric vehicle 312. The secondary resonator device 316 may further include a capacitive component 315, which together with the inductive component forms an electromagnetic resonance circuit. According to some illustrative examples herein, the secondary resonator device 316 may be provided by the inductive component 100 referred to above Figures 3a to 3d described.

[0093] In some illustrative embodiments of the present invention, the main resonator device 302a on the ground side may include a coil structure having two windings connected in parallel, each winding having 13 turns. The secondary resonator device 316 on the vehicle side may represent a resonator device having the same structure as or a similar structure to the main resonator device 302a, having 17.5 turns and a smaller ferrite volume in the core.

[0094] While there is currently no established standard defining the framework conditions for contactless energy transfer systems, industry-wide specifications have been established that define acceptable standards for interoperability, electromagnetic compatibility, EMF, minimum power, safety, and testing for wireless charging of light electric vehicles and electric plug-in vehicles. On this basis, three vehicle classes have been defined, each with a different distance from the ground, the so-called ground clearance or "GC", and in addition, the allowable offset between the primary and secondary resonator devices has been defined. The distance GC can vary between 100 and 250 mm, and the allowable offset can range from 0 / 0 (x-direction / y-direction) to ±75 / ±100 mm.

[0095] When an electric vehicle 312 is parked on one of the primary resonator devices 302a, 302b, the charging process can be started, for example, by communication between the charging controller 314 and the power distribution device 330 via the communication device 334, where the primary resonator device on which the electric vehicle 312 has been parked is operated. In the Figure 4 example, it is the primary resonator device 302a. By near-field transmission, an inductive coupling is established between the primary resonator device 302a and the secondary resonator device 316, which receives electromagnetic energy from the primary resonator device 302a and charges the energy storage device 318 via the charging controller 314 (e.g., including a suitable rectifier circuit). The state of charge of the energy storage device 318 can be monitored here by the charging controller 314, and when the desired state of charge has been reached, the charging process can be terminated by communication with the power distribution device 330. The charging system 300 can be configured to detect the presence of an object or a living being between the secondary resonator device 316 and the primary resonator device 302a or 302b, respectively, and thus the charging process can be interrupted when a positive event ("object or living being on or too close to the primary resonator device") is detected.

[0096] If an offset occurs when the electric vehicle 312 is parked compared to the arrangement with optimal coupling, the system's framework conditions will change due to the offset between the primary and secondary resonator devices, as explained above with reference to Figures 1c to 1f. For example, the inductance of the primary and secondary resonator devices decreases with increasing offset, as does the magnetic coupling k and the mutual inductance M.

[0097] Reference Figure 5, which presents a schematic circuit diagram of a resonant circuit 400 of a contactless energy transfer system for charging an electric vehicle (not shown) according to an exemplary embodiment of the present invention. The schematic circuit diagram of the resonant circuit 400 includes two terminals A1 and A2, which can be connected to a power supply circuit (not shown) for supplying energy to the contactless energy transfer system or to a rectifier circuit (not shown). An input filter device 410 having inductors L_F1.1 and L_F1.2 and a capacitor C_F are connected downstream of the terminals A1 and A2. In addition, a plurality of windings are provided, which are provided by a first set of windings 422 and a second set of windings 432 according to the illustration in Figure 5 . In addition, a plurality of capacitors are provided, such as a capacitor C_S1 associated with the first set of windings 422 and a capacitor C_S3 associated with the second set of windings 432. In the schematic example, the capacitor C_S1 is connected in series with the first set of windings 422, and the capacitor C_S3 is connected in series with the second set of windings 432. The schematic circuit diagram of the resonant circuit 400 further includes two switching elements 440 and 450. A connection node 460 is provided between the first set of windings 422 and the second set of windings 432. The connection node 460 is connected to the terminal A2 via the switching element 440, and the connection node 460 is connected to the terminal A1 via the first set of windings 422. In addition, the switching element 450 is arranged between the second set of windings 432 and the terminal A2. The two switching elements 440 and 450 are connected to each other in a star configuration at the connection node 465, such that the connection node is arranged in a star configuration between the switching elements 440 and 450 and the terminal A2. In other words, leads are formed as pins or rays emanating from the connection node 465 and are connected to the switching elements 440 and 450 and the terminal A2 respectively. According to the illustrated embodiment, only the switching element 440 and the switching element 450 are provided, thus avoiding circuit complexity. The connection node 465 is arranged between the switching elements 440 and 450, and each of the switching elements 440 and 450 is connected to the terminal A2 via the connection node 465. In particular, the connection node 465 is formed in a star configuration, where leads are formed as pins or rays emanating from the connection node 465, and each lead is connected to the switching elements 440 and 450 and the terminal A2.

[0098] In some of the schematic examples herein, the two switching elements 440, 450 are configured such that as long as the switching element 440 is closed, the switching element 450 is open. In this case, the switching element 450 is only closed when the switching element 440 is open. Thus, the configuration of the switching elements 440, 450 is defined in these exemplary examples.

[0099] According to some schematic embodiments, a plurality of windings including the first set of windings 422 and the second set of windings 432 are provided as a hybrid double-D solenoid coil on a plate-shaped ferrite core (not shown), as described above with respect toFigure 2 and Figures 3a - 3d As described. The coil structure based on the hybrid double D solenoid coil allows for a relatively large coupling of the primary and secondary resonator devices relative to each other at large distances and / or offsets.

[0100] Referring Figure 5 to the illustration in, the first set of windings 422 can be formed by two electrically identical winding packages L1.1 and L1.2 connected in parallel. In this case, the current-carrying capacity of the first set of windings can be increased. The current values and voltage values of the winding packages L1.1 and L1.2 connected in parallel in the electrically identical winding packages are the same, thus preventing the equalizing current between the winding packages connected in parallel. By using the winding packages connected in parallel.

[0101] As further shown in Figure 5 , the second set of windings 432 can additionally or alternatively be formed by two electrically identical winding packages L2.1 and L2.2 connected in parallel. Using the winding packages L2.1 and L2.2 connected in parallel allows for partially or completely eliminating the induced voltage in the unused winding turns of the second set of windings that are cut off when the switching element 450 is open. Using the winding packages L2.1 and L2.2 connected in parallel can also increase the current-carrying capacity of the second set of windings 432. According to some illustrative examples herein, the respective winding packages L2.1 and L2.2 of the second set of windings 432 connected in parallel can be connected in series with associated additional capacitors C_S2.1 and C_S2.2. For example, the associated additional capacitors C_S2.1 and C_S2.2 with the winding packages L2.1 and L2.2 of the second set of windings 432 can be configured such that the interconnection of the winding packages L2.1 and L2.2 connected in parallel of the second set 432 with the associated additional capacitors C_S2.1 and C_S2.2 has a resonance frequency greater than the operating frequency of the non-contact energy transfer system, while the resonance frequency of the resonance circuit 400 formed by connecting the first and second sets of windings 422, 432 in series with the associated capacitors C_S1, C_S2.1, C_S2.2, and C_S3 has a resonance frequency that is substantially equal to the operating frequency of the non-contact energy transfer system. The term "substantially" currently means a deviation of less than 30%, preferably less than 15%, more preferably less than 10%, such as less than 5% or even less than 1%. Thus, it is achieved that the impedance of the cut-off turns of the second set of windings 432 is high and the equalizing current is suppressed. When the second switching element 450 is now open, the parallel connection of the winding packages L2.1 and L2.2 of the second set of windings 432 becomes a series connection in which the winding packages L2.1 and L2.2 of the second set of windings 432 are switched in anti-parallel to each other. This ensures that the voltages induced in the turns of the second set of windings 432 cancel each other out.

[0102] In each operating mode of the resonant circuit 400, it is possible to achieve that the resonant circuit 400 remains resonant at the operating frequency of the non-contact energy transfer system. For example, the operating frequency of the non-contact energy transfer system can be in the range from 80 kHz to 90 kHz, where good energy transfer efficiency can be obtained. According to another example, the resonant frequency of the interconnection of the parallel winding packages L2.1 and L2.2 of the second set of windings 432 and the associated additional capacitors C_S2.1 and C_S2.2 except for the capacitor C_S3 can be greater than 90 kHz, so that the resonant frequency of the interconnection of the parallel winding packages L2.1 and L2.2 of the second set of windings 432 and the associated additional capacitors C_S2.1 and C_S2.2 is far enough away from the operating frequency of the non-contact energy transfer system.

[0103] In some illustrative embodiments of the present invention, the first set of windings 422 may have a first number of turns in the range from 5 to 20 turns, and the second set of windings 432 may have a second number of turns in the range from 1 to 10 turns. Among them, the first number of turns may be greater than the second number of turns. This enables the compact resonant circuit to have favorable energy transfer efficiency.

[0104] In an illustrative example, the first number of turns may be in the range from 7 to 12 turns, such as 8 or 9 or 10 or 11 turns. The second number of turns may be in the range from 2 to 6 turns, such as 3 or 4 or 5 turns. However, this does not constitute a limitation on the present invention, and any number for the first number of turns and the second number of turns can be considered.

[0105] In some illustrative embodiments herein, the resonant circuit 400 may be a main resonator device in a main charging system (not shown) for charging an electric vehicle (not shown), thereby providing a favorable main resonator device, or a secondary resonator device in a secondary charging system (not shown) for charging an electric vehicle (not shown).

[0106] For example, Figure 5 the resonant circuit 400 in allows the number of turns of multiple windings of the resonant circuit to change during operation, for example, decrease or increase. The number of turns is decreased according to whether the switch element 440 is closed and the switch element 450 is opened, or increased according to whether the switch element 440 is opened and the switch element 450 is closed.

[0107] Regarding the input filter 410, an LC filter arrangement with a coupling choke is provided in two power supply lines between the terminals A1 and A2 and the groups 422 and 432 of windings.

[0108] Regarding the first set of windings 422, it is compensated by an associated capacitor C_S1 (e.g., connected in series).

[0109] Regarding the second set of windings 432, a capacitor C_S3 is currently associated. Additionally, according to Figure 5 the illustration in

[0110] capacitors C_S2.1 and C_S2.2 are additionally provided such that the second set of windings 432 with the winding packages L2.1 and L2.2 in parallel are compensated by the three capacitors C_S2.1, C_S2.2, and C_S3.

[0111] In the operating mode using all turns of multiple windings, the switching element 440 is open and the switching element 450 is closed. In this case, the winding packages L2.1 and L2.2 are in parallel and are compensated by the combination of the capacitors C_S2.1, C_S2.2, and C_S3. The capacitances of the capacitors C_S2.1 and C_S2.2 are added as a parallel connection of capacitors. Overall, these capacitors are designed such that the system operates resonantly at the operating frequency (e.g., at 85 kHz). Figure 5 In the operating mode with a reduced number of turns relative to the above operating mode, the switching element 440 is closed and the switching element 450 is open. This bypasses the second set of windings 432 together with the associated capacitors. By opening the switching element 450, the parallel connection of the winding packages L2.1 and L2.2 of the second set of windings 432 becomes a series connection, and the induced voltages of the winding packages L2.1 and L2.2 cancel each other out. Capacitors C_S2.1 and C_S2.2 are provided such that the resonance of the second set of windings 432 in this operating mode is now away from the operating frequency. As a result, there is a high impedance effect and only a very small balancing current can flow. As

[0112] shown in Figure 5 the disconnected turns of the second set of windings 432 continue to be connected to the circuit at the connection point 460 in this operating mode, with the result that they have a defined electrical potential and prevent damage caused by potential differences. Figure 5 Although a schematic embodiment is described with reference to Figure 5An additional switching element (not shown) of the connection node of the connection node 465 therein is connected to the inductor. Therefore, different numbers of windings can be continuously set by selectively turning on or off the inductor. Additionally or alternatively, several inductors can be connected in parallel with each other to provide an effective inductance for the circuit formed by the inductors connected in parallel. This allows for a finer adjustment of the inductance of the circuit.

[0113] In these schematic embodiments not shown, a non-contact energy transfer system for charging an electric vehicle is provided with a resonant circuit that includes a first terminal and a second terminal, a plurality of windings, a plurality of capacitors, a first switching element, and a second switching element, wherein the resonant circuit can be connected to a power supply circuit or a rectifier via the first terminal and the second terminal, wherein the plurality of windings are divided into a first group of windings, a second group of windings, and at least a third group of windings, wherein each group of windings is associated with at least one capacitor among the plurality of capacitors that is connected in series to the windings of the associated group, wherein the resonant circuit further includes a connection node that connects the first group of windings, the second group of windings, and at least the third group of windings in a star configuration such that the connection node is first arranged between the first group of windings and the second group of windings, and the connection node is connected to the first terminal via the first switching element, and secondly, the connection node is arranged between the first group of windings and the third group of windings and is connected to the first terminal via an additional (third) switching element associated with the third group of windings, wherein the connection node is connected to the second terminal via the first group of windings, wherein the second switching element is arranged between the second group of windings and the first terminal, and wherein the other switching element associated with the third group of windings is connected to the first terminal. A fourth group of windings and an associated additional (fourth) switching element can be provided, which is connected to the star connection node, wherein the connection node is arranged between the first group of windings and the fourth group of windings and is connected to the first terminal via the additional (fourth) switching element associated with the fourth group of windings. This can continue as needed such that generally n (n>1) groups of windings are provided, wherein the nth group of windings is associated with the nth switching element, the nth group of windings is connected to the connection node such that the connection node is arranged between the first group of windings and the nth group of windings and is connected to the first terminal via the nth switching element. However, in any case, the connection node is connected to the second terminal via the first group of windings, and the connection node is further connected to the first terminal via the first switching element. This describes, for example, in the case of a star connection node 460 or 465 having three pins or rays, forming two pins or rays such that they are both connected to a series circuit section formed by a group of windings and a switching element. This means that for a star connection node having three pins or rays, two pins or rays are both connected to the series circuit section, or generally, for a star connection node having n pins or rays, (n - 1) pins or rays are both connected to the series circuit section.

[0114] ReferenceFigure 6 FIG. 500 shows a schematic circuit diagram of a resonant circuit 500 for a non-contact energy transfer system according to a further schematic embodiment of the present invention. The schematic circuit diagram of the resonant circuit 500 includes two terminals A3 and A4, which can be connected to a power supply circuit (not shown) for supplying energy to the non-contact energy transfer system or to a rectifier circuit (not shown).

[0115] Similar to Figure 5 the resonant circuit 400, the terminals A3 and A4 may have an input filter device (not shown) downstream, and the input filter device may be configured according to Figure 5 the input filter device 410.

[0116] In addition, a plurality of windings are provided, which, according to Figure 6 the illustration in, are provided by a first set of windings 522 and a second set of windings 532. A plurality of capacitors are further provided such that the first set of windings 522 is associated with capacitors C4 and C5, and the second set of windings 532 is associated with capacitor C3. In the schematic example, capacitors C4 and C5 are connected in series to the first set of windings 522, and capacitor C3 is connected in series to the second set of windings 532.

[0117] According to Figure 6 the illustration in, the schematic circuit diagram of the resonant circuit 500 further includes two switching elements 540 and 550. According to the illustrated embodiment, only the switching element 440 and the switching element 450 are provided, thus avoiding circuit complexity. A connection node 560 is provided between the first set of windings 522 and the second set of windings 532, and the connection node 560 is connected to the terminal A4 via the switching element 540. In addition, the connection point 560 is connected to the terminal A3 via the first set of windings 522. In addition, the switching element 550 is arranged between the second set of windings 532 and the terminal A4. In addition, a connection node 565 is arranged between the switching elements 540 and 550, and each of the switching elements 540 and 550 is connected to the terminal A4 via the connection node 565.

[0118] In some of the schematic examples herein, the two switching elements 540, 550 are configured such that as long as the switching element 540 is closed, the switching element 550 is open. In this case, the switching element 550 is only closed when the switching element 540 is open. Therefore, the configuration of the switching elements 540, 550 is defined in these exemplary examples.

[0119] According to some schematic embodiments, a plurality of windings including the first set of windings 522 and the second set of windings 532 are provided as a hybrid double-D solenoid coil on a plate-shaped ferrite core (not shown), as described above with respect to Figure 2 and Figures 3a - 3dAs described. The coil structure based on the hybrid double D solenoid coil allows for a relatively large coupling between the primary and secondary resonator devices at large distances and / or offsets relative to each other.

[0120] In a schematic embodiment of the invention, the capacitor C3 associated with the group of windings 532 is configured such that the connection of the group of windings 532 to the associated capacitor C3 has a resonance frequency greater than the operating frequency of the contactless energy transfer system, while the resonance frequency of the resonance circuit 400 for the series connection of the first and second groups of windings 522, 532 to the associated capacitors C3 to C5 has a resonance frequency substantially equal to the operating frequency of the contactless energy transfer system. The term "substantially" currently means a deviation of less than 30%, preferably less than 15%, more preferably less than 10%, such as less than 5% or even less than 1%. Thus, it is achieved that the impedance of the cut-off turns of the second group of windings 532 is high and the balancing current is suppressed.

[0121] In each operating mode of the resonance circuit 500, it is possible to achieve that the resonance circuit 500 remains in resonance at the operating frequency of the contactless energy transfer system. For example, the operating frequency of the contactless energy transfer system can be in the range from 80 kHz to 90 kHz, where good energy transfer efficiency can be obtained. According to a further example, the resonance frequency of the second group of windings 532 with the associated capacitor C3 can be greater than 90 kHz, such that the resonance frequency of the interconnection of the second group of windings 532 with the associated capacitor C3 is sufficiently far from the operating frequency of the contactless energy transfer system.

[0122] In some schematic embodiments of the invention, the first group of windings 522 can have a first number of turns in the range from 5 to 20 turns, and the second group of windings 532 can have a second number of turns in the range from 1 to 10 turns. Wherein, the first number of turns can be greater than the second number of turns. This enables a compact resonance circuit to have favorable energy transfer efficiency.

[0123] In a schematic example, the first number of turns can be in the range from 7 to 12 turns, such as 8 or 9 or 10 or 11 turns. The second number of turns can be in the range from 2 to 6 turns, such as 3 or 4 or 5 turns. However, this does not constitute a limitation of the invention, and any number can be considered for the first and second numbers of turns.

[0124] In some schematic embodiments herein, the resonance circuit 500 can be the primary resonator device in a primary charging system (not shown) for charging an electric vehicle (not shown), thereby providing a favorable primary resonator device, or the secondary resonator device in a secondary charging system (not shown) for charging an electric vehicle (not shown). Figure 5The resonant circuit 400 described in the context below implements the regulation of mutual inductance, as will be explained in more detail below, while the regulation of the resonant frequency does not occur or occurs substantially not at all. Regardless of the switching configuration of the switching element, the windings remain magnetic in the system. The parallel configuration design of windings L2.1 and L2.2 can reduce the heat dissipation losses in windings L2.1 and L2.2, especially when they are "cut off" when the switching element 450 is turned on, as derived from Figure 5 the above description.

[0125] As Figure 6 shown, in the case of the operating mode where the switching element 550 is turned on, the disconnected turns of the second set of windings 532 continue to be connected to the circuit at the connection point 560, as a result of which they have a defined electrical potential and prevent damage caused by the potential difference.

[0126] Although the schematic embodiment is described with reference to Figure 5 where the connection node 560 is shown in a star configuration with three pins, this does not constitute any limitation to the present invention. In an alternative embodiment (not shown), the connection node 560 can be shown in a star configuration with more than three pins or rays, as Figure 5 shown to form three pins or rays, while each additional pin or ray relative to these three pins or rays emanating from the star connection node travels from the connection node to an inductor with a certain number of turns and is then connected to the inductor via an additional switching element (not shown) having a connection node corresponding to Figure 6 the connection node 565 in. Thus, different numbers of windings can be continuously set by selectively turning on or off the inductor. Additionally or alternatively, several inductors can be connected in parallel with each other to provide an effective inductance for the circuit formed by the inductors connected in parallel. This allows for a finer regulation of the inductance of the circuit.

[0127] In these schematic embodiments not shown, a non-contact energy transfer system for charging an electric vehicle is provided with a resonant circuit. The resonant circuit includes a first terminal and a second terminal, a plurality of windings, a plurality of capacitors, a first switching element, and a second switching element. Among them, the resonant circuit can be connected to a power supply circuit or a rectifier via the first terminal and the second terminal. Among them, the plurality of windings are divided into a first group of windings, a second group of windings, and at least a third group of windings. Each group of windings is associated with at least one capacitor in the plurality of capacitors that is connected in series to the windings of the associated group. The resonant circuit further includes connection nodes that connect the first group of windings, the second group of windings, and at least the third group of windings in a star configuration, such that the connection node is first arranged between the first group of windings and the second group of windings, and the connection node is connected to the first terminal via the first switching element. Secondly, the connection node is arranged between the first group of windings and the third group of windings and is connected to the first terminal via an additional (third) switching element associated with the third group of windings. The connection node is connected to the second terminal via the first group of windings. The second switching element is arranged between the second group of windings and the first terminal, and the additional switching element associated with the third group of windings is connected to the first terminal. A fourth group of windings and an associated another (fourth) switching element connected to the star connection node can also be provided. The fourth group of windings is connected to the star connection node, where the connection node is arranged between the first group of windings and the fourth group of windings and is connected to the first terminal via the another (fourth) switching element associated with the fourth group of windings. This can continue as needed, such that generally n (n>1) groups of windings are provided. The nth group of windings is associated with the nth switching element. The nth group of windings is connected to the connection node, such that the connection node is arranged between the first group of windings and the nth group of windings and is connected to the first terminal via the nth switching element. However, in any case, the connection node is connected to the second terminal via the first group of windings, and the connection node is also connected to the first terminal via the first switching element. This describes, for example, such an embodiment: a star connection node 560 and / or 565 with three pins or rays and two pins or rays is formed, such that they are all connected to a series circuit section formed by a group of windings and a switching element. This means that for a star connection node with three pins or rays, two pins or rays are both connected to the series circuit section, or generally for a star connection node with n pins or rays, (n - 1) pins or rays are both connected to the series circuit section.

[0128] Reference Figure 7 Illustrates the measurement results of a non-contact energy transfer system according to a schematic embodiment of the present invention. Figure 7 Graphically represents the inductance of the resonator device ( Figure 7 left ordinate) and the coupling between the main and secondary resonator devices ( Figure 7 abscissa) of the measured relationship, as well as the mutual inductance of the resonator deviceFigure 7 right vertical coordinate) and coupling ( Figure 7 abscissa). It can be seen here that when compared with the comparative example of Fig. 1f, the change in the mutual inductance M can be limited within a relatively small operating range.

[0129] It can also be seen that in Figure 5 the embodiment (not shown) in which the connection node 460 shown forms more than three pins in a star shape, a larger number of partitions of the winding can be connected, and the mutual inductance M of the circuit can also be finely adjusted by the parallel connection of several inductors. Referring to Figure 7 , this means that Figure 7 the single step shown is replaced by several smaller steps, so that in this case the change in the mutual inductance M can be limited within an even smaller operating range than Figure 7 shown.

[0130] In summary, the change in the mutual inductance of the transmission system with an air gap and the changed coupling conditions are compensated for in terms of functional critical variables. In some exemplary embodiments, the additional advantage of a hybrid double-D solenoid coil system is used, which has a large achievable coupling combined with mutual inductance adaptation, enabling efficient transmission of high power at all operating points. A circuit structure is provided here, which enables a specific number of turns of the resonant circuit to be disconnected without impairing the function of the system or causing significant additional losses and limiting the change in the mutual inductance. In the exemplary embodiments of the present invention, the coil structure of the coil of the resonator for non-contact energy transmission is feasible, where good efficiency is achieved through mutual inductance adaptation despite large differences in the coupling between the resonators.

Claims

1. A non-contact energy transfer system for charging an electric vehicle, having a primary resonator device and a secondary resonator device, wherein, At least one of the main resonator device and the secondary resonator device includes a resonant circuit (400; 500) of a non-contact energy transfer system for charging an electric vehicle, wherein the resonant circuit (400; 500) includes a first terminal (A2; A4), a second terminal (A1, A2), a plurality of windings (160), a plurality of capacitors, a first switching element (440; 540) and a second switching element (450; 550), and wherein the resonant circuit (400; 500) can be connected to a power supply circuit or a rectifier via the first terminal (A2; A4) and the second terminal (A1, A2). Wherein the plurality of windings (160) are divided into a first group of windings (422; 522) and a second group of windings (432; 532). Wherein a first connection node (460; 560) is arranged between two corresponding ones of the first group of windings (422; 522), the second group of windings (432; 532) and the first switching element (450; 550), such that the first connection node (460; 560) is connected to the first terminal (A2; A4) via the first switching element (440; 540) and to the second terminal (A1; A3) via the first group of windings (422; 522), and wherein the first connection node (460; 560) is formed in a star configuration. Wherein the second switching element (450; 550) is arranged between the second group of windings (432; 532) and the first terminal (A2; A4), and Wherein the second group of windings (432) is formed by two electrically identical windings encapsulated in parallel (L2.1, L2.2), and each of the windings encapsulated in parallel (L2.1, L2.2) of the second group of windings (432) is connected in series with an associated additional capacitor (C_S2.1, C_S2.2), and wherein the additional capacitors (C_S2.1, C_S2.2) associated with the windings encapsulated in parallel (L2.1, L2.2) of the second group of windings (432) are configured such that the interconnection of the windings encapsulated in parallel (L2.1, L2.2) of the second group of windings (432) with the associated additional capacitors (C_S2.1, C_S2.2) has a resonant frequency greater than the operating frequency of the non-contact energy transfer system, while the resonant frequency of the resonant circuit (400) for the series connection of the first and second groups of windings (422, 432) with the associated capacitors (C_S1, C_S2.1, C_S2.2, C_S3) has a resonant frequency substantially equal to the operating frequency of the non-contact energy transfer system.

2. The non-contact energy transfer system according to claim 1, further comprising a third set of windings and a third switching element connected in series therewith, wherein, The third group of windings and the third switching element connected in series therewith are connected in parallel to the first connection node (460; 560) with the second group of windings (432; 3. The contactless energy transfer system according to claim 2, wherein, The second connection node (465; 565) is arranged between the first switching element (440; 540) and the second switching element (450; 550), and the first switching element (440; 540) and the second switching element (450; 550) are connected to the first terminal (A2; A4) via the second connection node.

4. The non-contact energy transfer system according to claim 3, wherein The second connection node (465; 565) is further formed in a star configuration between the first switching element (440; 540), the second switching element (450; 550) and the first terminal (A2; A4), and the third set of windings and the third switching element connected in series therewith are connected in parallel with the second set (432; 532) and the first switching element (440; 540) between the first connection node (460; 560) and the second connection node (465; 565).

5. The non-contact energy transfer system according to claim 3, wherein The second connection node (465; 565) is formed in a star configuration between the first switching element (440; 540), the second switching element (450; 550) and the first terminal (A2; A4).

6. The contactless energy transfer system according to claim 5, further comprising another circuit segment having a fourth set of windings and a fourth switching element, wherein, The other circuit segment is connected in parallel with the second set of windings (432; 532) to the second connection node (465; 565).

7. The non-contact energy transfer system according to claim 6, wherein, The second connection node (465; 565) is further formed in a star configuration between the first switching element (440; 540), the second switching element (450; 550) and the first terminal (A2; A4), and the other circuit segment is connected in parallel with the second set (432; 532) and the first switching element (440; 540) between the first connection node (460; 560) and the second connection node (465; 565).

8. The contactless energy transfer system according to claim 1, wherein, The two switching elements (440, 450; 540, 550) are configured such that as long as the first switching element (440; 540) is closed, the second switching element (450; 550) is open, and the second switching element (450; 550) is closed only when the first switching element (450; 550) is open.

9. The non-contact energy transfer system according to claim 1, wherein, The plurality of windings (160) are provided as hybrid double-D solenoid coils (150) on a plate-shaped ferrite core (110).

10. The contactless energy transfer system according to claim 1, wherein, Both the first set of windings (422) and / or the second set of windings (432) are formed by two electrically identical windings connected in parallel (L1.1, L1.2; L2.1, L2.2).

11. The contactless energy transfer system according to any one of claims 1 to 10, wherein, The first set of windings (422; 522) has a first number of turns in the range from 5 to 20 turns, and the second set of windings (432; 532) has a second number of turns in the range from 1 to 10 turns, wherein the first number of turns is greater than the second number of turns.

12. The contactless energy transfer system according to claim 1, wherein, The resonant frequency at which the parallel windings (L2.1, L2.2) of the second set of windings (432) are interconnected with the associated additional capacitors (C_S2.1, C_S2.2) is greater than 90 kHz.

13. The non-contact energy transfer system according to claim 1 or 12, wherein, The operating frequency of the non-contact energy transfer system is in the range of 80 to 90 kHz.

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