WO2018077580A1

WO2018077580A1 - Protection device for an inductive energy transmission system and inductive energy transmission system

Info

Publication number: WO2018077580A1
Application number: PCT/EP2017/075133
Authority: WO
Inventors: Bernhard Mader; Oliver Blum
Original assignee: Robert Bosch Gmbh
Priority date: 2016-10-26
Filing date: 2017-10-04
Publication date: 2018-05-03

Abstract

The invention relates to a protection device for an inductive energy transmission system. A screen is provided between the primary coil and the secondary coil for inductive energy transmission, said screen being permeable to the magnetic field of the inductive energy transmission as well as reliably screening applied electric fields. For this purpose in particular, a suitable circuit path structure, in which no eddy currents form, can be provided.

Description

description

title

Protection device for an inductive energy transmission system and inductive energy transmission system

The present invention relates to a protective device for an inductive power transmission system with a primary coil and a secondary coil and an inductive energy transmission system with such

Protective device.

State of the art

The document DE 10 2011 010 049 AI discloses a device for charging a battery of a vehicle, wherein the electrical energy for charging the battery between a coil in the vehicle and a coil in the

Charging station is transmitted inductively.

Inductive energy transfer systems require magnetic fields for

Energy transfer. Especially with resonant inductive

Energy transmission systems also generate high high-frequency alternating voltages when generating the magnetic fields in the transmission coils.

Metal surfaces near the transmission coils form with these

Transmission coils a capacitor. In this way, the metal surfaces in the vicinity of the transmission coils for an alternating current to the

Reference potential of the transmission coils coupled. For example, to prevent electrical current flow upon contact of the metal surfaces, the metal surfaces may be electrically connected to the reference potential, or the transmission coils may be electrically isolated. Disclosure of the invention

The present invention discloses a protective device for an inductive power transmission system having the features of claim 1 and an inductive power transmission system having the features of claim 9.

Accordingly, it is provided:

A protection device for an inductive power transmission system having a primary coil and a secondary coil. The protection device comprises a shielding device. The shielding means is disposed between the primary coil and the secondary coil. Furthermore, the protection device is designed to shield an electric field of the primary coil.

Furthermore, it is provided:

An inductive power transmission system having a primary coil adapted to orgatively provide an alternating magnetic field and a shielding device according to the invention. The screen device shields a parasitic alternating electrical field of the primary coil.

Advantages of the invention

The present invention is based on the finding that in an inductive energy transfer, in particular in an inductive

Energy transmission with resonant systems, including high-frequency alternating voltages arise. Metal surfaces in the vicinity of the transmission coils of an inductive energy transmission system in this case form a capacitor. Will these metal surfaces near the

When the transmission coil touches during the inductive energy transmission, a significant alternating electric current can flow.

The present invention is therefore based on the idea to take this finding into account and a protective device for an inductive Provide energy transfer, which an undesirable capacitive current flow at a contact of metal surfaces in the vicinity of

Prevent transmission coils in the inductive energy transfer or at least significantly minimize.

For this purpose, it is provided that the alternating electric field, which arises during the inductive energy transmission, by means of a suitable

Shield screen device. If the electric field during the inductive energy transfer shielded, so can also in the

Surrounding metal surfaces even if touched by a person no or only a small amount of electric current flow. In this way can be very reliable protection against dangerous

Leakage be realized in one touch.

Since the danger of significant and sometimes dangerous electrical alternating currents in the event of contact by the shield device can be prevented by the protective device according to the invention, no further complex additional protective measures are required. As a result, the inductive power transmission system can be simplified. In particular, the required costs for a safe inductive energy transmission system are reduced.

According to one embodiment, the screening device is for one of

Primary coil generated alternating magnetic field permeable. The

Umbrella device thus absorbs exclusively the alternating electric field, while the magnetic alternating field can continue to pass through the shield device unhindered or at least approximately unhindered.

According to one embodiment, the screening device is provided with a

Reference potential of the primary coil electrically coupled. In particular, the shield device can be electrically coupled to a reference potential, which corresponds to the reference potential of the environment on which the primary coil is arranged. In this way, the screen device and

Persons in the vicinity of the inductive energy transmission system at the same electrical potential. According to one embodiment, the screening device comprises a plurality of radial conductor tracks. In particular, the central point at which the beams of this radial track arrangement meet can coincide with a point on a center axis of the primary coil. By such a radial track arrangement, a good absorption of the electric alternating fields while minimizing absorption of

magnetic alternating fields are achieved.

According to an alternative embodiment, the shielding device comprises a plurality of parallel conductor tracks. The conductor tracks are electrically connected to each other here. The interconnects may, for example, have a comb-shaped or a meander-shaped interconnect structure. By such a conductor track arrangement having a plurality of parallel arranged

Conductor tracks can also be achieved a good absorption of the electric alternating fields, without the magnetic alternating field is significantly attenuated.

According to one embodiment, adjacent conductor tracks have a maximum distance of 1 mm. In particular, neighboring can

Conductor tracks have a distance of less than 1 mm, for example, 0.5 mm, 0.1 mm or less.

According to one embodiment, the conductor tracks of the screen device are arranged on an electrically insulating carrier substrate. By way of example, the electrically insulating carrier substrate may be a foil, in particular a plastic foil or the like. In this way, an efficient and inexpensive screen device can be realized.

According to one embodiment, the conductor tracks are printed on the electrically insulated carrier substrate. In particular, by printing electrical conductor track structures, a very flexible and inexpensive screen device can be realized.

According to one embodiment of the inductive energy transmission system, the shielding device is arranged on the primary coil. In particular, the Umbrella means an area which at least the surface of

Primary coil corresponds.

The above embodiments and developments can, as far as appropriate, combine arbitrarily. Further refinements, further developments and implementations of the invention also include combinations of previously or below that are not explicitly mentioned with respect to FIG

Embodiments described features of the invention. In particular, the person skilled in the art will also consider individual aspects as improvements or

Add additions to the respective basic forms of the present invention.

Brief description of the drawings

The present invention will be explained in more detail with reference to the exemplary embodiments indicated in the schematic figures of the drawings. Showing:

Figure 1: a schematic representation of an inductive

Energy transmission system with a screen device according to an embodiment;

Figure 2-5: schematic representations of screen devices according to

several embodiments of the present invention.

Embodiments of the invention

Figure 1 shows a schematic representation of an inductive

Energy transmission system according to one embodiment. The inductive energy transmission system comprises a primary coil 2. This primary coil 2 is designed to provide an alternating electric field. For this purpose, by means of a feed device 3 to the primary coil 2, an electrical

AC voltage can be provided. This alternating electrical voltage causes in the primary coil 2 an electrical alternating current, which in turn causes by the primary coil 3, an alternating magnetic field. The frequency The electrical alternating voltage and thus of the alternating magnetic field can correspond to any given frequency. In particular, for example, frequencies between 30 and 140 kHz, in particular frequencies in the range of 85 kHz are possible.

The alternating magnetic field generated by the primary coil 2 couples into a secondary coil 4 and thereby induces an alternating electrical current in the secondary coil 4. This alternating current can be provided, for example, to a charge controller 5. This charge controller 5 can then provide, for example, electrical energy to an electrical energy store 6, for example a traction battery of an electric or hybrid vehicle. In this way, the electrical energy storage 6 can be charged without a galvanic connection to an energy source has to be established between the electrical energy store 6 or the charge controller 5.

In addition, a protective device 1 is additionally arranged between the primary coil 2 and the secondary coil 4. In particular, this protection device 1 directly above the primary coil 2 or in a

predetermined distance from the primary coil 2 may be arranged. These

Protective device 1 in particular has a shielding device which shields an alternating electric field of the primary coil 2 in the direction of the secondary coil 4. In this way, high frequency alternating voltages occurring at the primary coil 2 during the inductive energy transmission can not be coupled to further metal parts in the region of the secondary coil 4.

The shielding device of the protection device 1 can for example be coupled to a reference potential of the primary side. For example, the

Screen device of the protective device 1 are electrically coupled to the potential on which the area around the primary coil 1 is located.

In order to ensure an inductive energy transfer despite the shielding of the electric fields by the shield device, which is

Screen device of the protective device 1 for magnetic fields, in particular for magnetic alternating fields permeable. For this purpose, the screen device designed such that due to the magnetic field of the primary coil 2 possible no or at least only very small eddy currents within the

Forming umbrella device. This can be achieved in particular by the fact that in the screen device no closed annular

Conductor structures or metallic surfaces are present. In addition, the shielding device may have any suitable structure which, on the one hand, shields as much as possible an electric field from the primary coil 2 and thereby transmits the magnetic fields generated by the primary coil 2. Some possible embodiments of this will be described in more detail below.

FIG. 2 shows a schematic illustration of a printed conductor structure for the screening device of the protective device 1 according to one embodiment.

In this case, the shield device has a plurality of parallel conductor tracks 10, which are electrically connected to one another at one end. In this way, a kind of comb-shaped conductor track structure arises. These

Conductor structure is electrically coupled at a location with a reference potential. For the best possible shielding of the electric fields, the distances between the individual adjacent interconnects 10 are each 1 millimeter or less. In particular, the distances between the individual conductor tracks 10 may each be 0.5 millimeters, 0.1 millimeters or less.

The conductor tracks 10 may be arranged in this embodiment, as well as in all subsequent example, on an electrically insulating carrier substrate (not shown here). For example, this electrically insulating carrier substrate may be a plastic film or the like. The individual conductor tracks 10 may also be arranged, for example, between two plastic films or between two electrically insulating substrates. In this way, reliable protection of the

Screen device to be achieved from damage.

In order to realize the desired printed conductor structure, the printed conductor structure can be printed on the carrier substrate, vapor-deposited or applied to the carrier substrate in any other method, for example. In particular, suitable materials for the conductor tracks 10, for example, metals such as silver, copper, aluminum or other electrically conductive substances such as graphite or the like in question.

FIG. 3 shows a schematic representation of a screen device according to a further embodiment. In this embodiment, the

Screen device also several parallel conductor tracks. However, the individual strip conductors 10 are not all electrically connected to one another on one side, but the strip conductor structure has a meander-shaped strip conductor structure. Also in this case is the

Conductor structure at a single point electrically coupled to a reference potential.

FIG. 4 shows a schematic illustration of a further embodiment of a shield device of the protective device 1. In this embodiment, the strip conductors 10 have a star-shaped structure. The individual conductor tracks 10 are electrically connected to each other at a central point, for example in the middle. Starting from this center, the conductor track structure has a radial geometry. Order here

For example, to achieve a more efficient shielding in the outdoor area, additional conductor tracks can optionally also be provided in the outer area, which are suitably connected to the conductor tracks which converge in the center. This track structure is also connected to a reference potential at a single point.

FIG. 5 shows a schematic representation of a screen device for a protective device 1 according to a further embodiment. In this

Embodiment, the shield means a meandering

Track structure, wherein the meandering track structure is arranged in the region of a circular ring. This annulus covers over here

for example, the area of the primary coil 2 arranged underneath. Here too, this conductor track structure is connected to a reference potential at one point. In this embodiment, as with all previously described

Embodiments, it is essential that no closed ring-shaped interconnect structures are formed. Therefore, the must

meander-shaped track structure in the annulus to be open at least one point.

The shield device can be provided in all embodiments, for example in the areas of the primary coil 2, where large voltages occur. In particular, for example, a printed conductor structure can be realized which preferably or exclusively shields edge regions of the primary coil 2. Furthermore, it is also possible that the screening device of

Protective device 1, the primary coil 2 covers the entire surface and is reinforced, for example, in particular at the areas where large voltages occur.

In summary, the present invention relates to a protection device for an inductive power transmission system. Between the primary coil and the secondary coil of an inductive energy transmission, a shield is provided, which although for the magnetic fields of the inductive

Energy transmission is permeable, but reliably shields occurring electric fields. For this purpose, in particular a suitable

Conductor be provided structure in which form no eddy currents.

Claims

claims

A protective device (1) for an inductive power transmission system comprising a primary coil (2) and a secondary coil (4), comprising: shielding means disposed between the primary coil (2) and the secondary coil (4) and adapted to to shield an electric field of the primary coil (2).

2. Protection device (1) according to claim 1, wherein the shielding device is permeable to a magnetic field generated by the primary coil (2).

3. Protection device (1) according to claim 1 or 2, wherein the

Screen device is electrically coupled to a reference potential of the primary coil (2).

4. Protection device (1) according to one of claims 1 to 3, wherein the screening device comprises a plurality of radial conductor tracks (10).

5. Protection device (1) according to one of claims 1 to 3, wherein the shielding device comprises a plurality of parallel conductor tracks (10).

6. Protection device (1) according to claim 5, wherein adjacent

Conductor tracks (10) have a maximum distance of one millimeter.

7. Protection device (1) according to one of claims 4 to 6, wherein the conductor tracks (10) are arranged on an electrically insulating carrier substrate.

8. Protection device (1) according to claim 7, wherein the conductor tracks (10) are printed on the electrically insulating carrier substrate.

9. An inductive power transmission system, comprising: a primary coil (2) adapted to provide an alternating magnetic field; and a screening device (1) according to one of claims 1 to 8.

10. Inductive energy transmission systems according to claim 9, wherein the screening device is arranged on the primary coil (2).