Electrostatic shielding devices and transformer devices including electrostatic shielding devices

Abstract

This disclosure relates to an electrostatic shielding element (1) arranged on a first axis (z) and comprising an electrostatic shielding volume (14) at least partially enclosed by a conductive coating (12), wherein the thickness (d) and conductivity (σ) of the coating (12) are selected such that a magnetic field of a predetermined frequency (f) can penetrate the coating and enter the volume (14). This disclosure also relates to an electrostatic shielding device (2) and a transformer device (3).

Description

Technical Field

[0001] This disclosure relates to an electrostatic shielding element and an electrostatic shielding device comprising at least two electrostatic shielding elements. More particularly, this disclosure relates to an electrostatic shielding element comprising an electrostatic shielding volume that can be penetrated by a magnetic field up to a predetermined frequency. Background Technology

[0002] The interaction between electronic devices and the background electric field necessitates complex considerations regarding the insulation of both the electronic device and surrounding equipment in high-voltage environments, making it difficult to place equipment exposed to high voltage. This complexity increases further if the equipment also requires magnetic coupling to external equipment or instruments.

[0003] Electronic equipment in high-voltage environments requires electrostatic shielding because conductive objects in high electric fields induce field enhancement, which increases the likelihood of partial discharge and accelerates the aging of any adjacent dielectric components and / or materials. Electrostatic shielding terminates electric field lines at the boundaries of the shielded area and also prevents magnetic fields from penetrating the shielding layer. Therefore, it is difficult to provide magnetic interactions, such as power transfer and / or signal transmission from outside the shielded area to the shielded equipment.

[0004] Electrostatic shielding needs to meet at least three requirements: - The conductivity of the shielding material should not be too low in order to provide an equipotential surface.

[0005] - The conductivity of the shielding material should not be too high to avoid inducing eddy currents that repel incident magnetic flux, and - The thickness of the shielding layer should be sufficient to achieve mechanical stability, but should be less than the skin depth of the magnetic field. Summary of the Invention

[0006] Therefore, the object of this disclosure is to provide an improved electrostatic shielding. In particular, the object of this disclosure is to provide an electrostatic shielding that allows power transmission and / or signal transmission with shielded electronic equipment.

[0007] According to a first aspect of this disclosure, this objective is achieved at least in part by an electrostatic shielding element in an electrostatic shielding device for high-voltage electric field applications.

[0008] Therefore, an electrostatic shielding element is provided, which is arranged on a first axis and includes an electrostatic shielding volume at least partially enclosed by a conductive coating. The thickness and conductivity of the coating are selected such that a magnetic field of a predetermined frequency can penetrate the coating and enter the volume. The conductivity and thickness of the coating are selected such that...

[0009] Where c ≤ 40,000 Sm / s, more preferably c ≤ 5,000 Sm / s, and most preferably c ≤ 1,000 Sm / s.

[0010] The electrostatic shielding volume is configured to be protected from the effects of electric fields at operating frequencies of 50 Hz / 60 Hz. For this purpose, the coating material needs to be sufficiently conductive. The coating material also needs to be continuous to completely enclose the volume.

[0011] By appropriately selecting the conductivity and thickness of the coating, a magnetic field can penetrate the volume, thereby enabling the transmission of power and signals to electrical equipment contained within the volume.

[0012] The coating is preferably a conductive metal coating. When the coating is exposed to an incident magnetic field, eddy currents are induced in the coating. The eddy current effect increases with the frequency of the magnetic field and prevents the magnetic field from penetrating the shielding volume. The eddy current effect decreases as the conductivity of the coating material decreases.

[0013] Thicker coatings require lower electrical conductivity than thinner coatings to allow magnetic fields to penetrate. However, thicker coatings have better mechanical strength than thinner coatings.

[0014] The frequencies of magnetic fields used in power transmission and signal transmission applications are typically between 20 kHz and 20 MHz. Therefore, designing electrical equipment and electronic components for predetermined frequencies within this range limits the range of selectable coating conductivity / materials and coating thicknesses. A constant c can be chosen to ensure that at least a portion of the magnetic field signal power penetrates the coating. At c = 40,000 Sm / s, approximately 10% of the signal power penetrates the coating. At c = 5,000 Sm / s, approximately 50% of the signal power penetrates the coating. At c = 1,000 Sm / s, approximately 90% of the signal power penetrates the coating.

[0015] Optionally, the electrostatic shielding volume is completely enclosed by a conductive coating.

[0016] For a single shielding element, the electrostatic shielding volume needs to be completely enclosed by a conductive coating. If the open area of ​​the volume is covered by an adjacent current-connected conductor (such as another shielding element), the volume can be partially enclosed, i.e., partially open.

[0017] Alternatively, the volume extends laterally from the first axis. The volume may be disk-shaped, and the volume extending laterally from the first axis is significantly larger than the volume extending laterally along the first axis.

[0018] Optionally, the volume is circular or elliptical about the first axis. The circular volume has a radius extending orthogonally to the first axis. The elliptical volume extends a first distance along a second (major) axis orthogonal to the first axis, and extends a second distance along a third (minor) axis orthogonal to both the first and second axes.

[0019] Since field reinforcement occurs at sharp corners and edges, a circular or elliptical volume is envisioned around the first axis. Furthermore, the radially outer edge of the volume may have a circular shape in a plane parallel to the first axis. The radius of curvature of the radially outer edge is preferably half the volume thickness at the radially outer edge (as seen along the first axis).

[0020] Optionally, the thickness of the conductive layer is less than or equal to 1 mm.

[0021] Optionally, the conductivity of the conductive layer is in the range of 1 S / m - 10. 8 Within the range of S / m, preferably within 10 3 S / m – 10 8 Within the range of S / m, and most preferably within 10 5 S / m – 10 8 Within the range of S / m.

[0022] Less than 10 8 The conductivity S / m range covers conductive materials. It is also conceivable to use semiconductor materials (such as those at 10 S / m). 5 Coatings of materials with a strength of approximately 1 S / m (e.g., carbon / graphite) and materials with a strength of approximately 1 S / m.

[0023] Optionally, the electrostatic shielding element includes at least one electrical device enclosed within a volume. The electrical device is configured to receive electrical power via inductive coupling and / or communicatively couple to a magnetic field of a predetermined frequency.

[0024] Therefore, electrical equipment can be enclosed and electrostatically shielded within the coated volume. Electricity can be received and transmitted to another electrical device or component in an inductive manner. Additionally, the electrical equipment can be communicatively coupled to a magnetic field to receive signals from and / or transmit signals to receivers / transmitters outside the electrostatically shielded volume via the magnetic field. Thus, the electrostatic shielding element can be located in a high-voltage electric field without risking damage to the electrical equipment or surrounding instruments and / or equipment.

[0025] Optionally, the electrical equipment includes at least one LC circuit.

[0026] LC circuits may include a single LC circuit or multiple LC circuits (such as an array of LC circuits).

[0027] According to a second aspect of this disclosure, this objective is achieved at least in part by means of an electrostatic shielding device.

[0028] Therefore, an electrostatic shielding device is provided, comprising at least two electrostatic shielding elements electrically connected to each other according to any of the embodiments of the first aspect of this disclosure. The at least two electrostatic shielding elements are arranged spaced apart from each other along a first axis, thereby forming an electrostatic shielding space between the at least two electrostatic shielding elements.

[0029] Therefore, the current connection between at least two electrostatic shielding elements ensures an equipotential surface across the entire surface of the electrostatic shielding device. Both are arranged on the first axis, for example, parallel to the first axis. Thus, the electrostatic shielding space between the electrostatic shielding elements also extends laterally to the ground from the first axis. This space may include any components that need to be shielded from the electric field but need to be in contact with the environment outside the electrostatic shielding elements.

[0030] Optionally, at least two electrostatic shielding elements are mechanically and electrically connected to each other via at least one conductive fixing element.

[0031] The current connection can be achieved by a conductive fixing element (such as a screw or bolt) that engages at least two electrostatic shielding elements. The fixing element can also be made conductive by a conductive coating (such as the same coating as the at least two electrostatic shielding elements).

[0032] Optionally, the electrostatic shielding device includes at least one electronic component arranged in the electrostatic shielding space, and the electrical equipment is electrically connected to the electronic component.

[0033] Electronic components can be located in an electrostatically shielded space without risking interference from electric fields. Electrical components can be electrically connected to electrical devices inside the electrostatically shielded element via electrical conductors that pass through the coating of the electrostatically shielded element in the area bordering the electrostatically shielded space.

[0034] Optionally, at least two electrostatic shielding elements are spaced apart from each other by a separation distance, and the electronic components are located in the shielding space at least at this separation distance from the radial periphery of the at least two electrostatic shielding elements.

[0035] According to a rule of thumb, the electric field is negligible at a distance equal to the separation distance from the radial periphery of at least two electrostatic shielding elements. Therefore, if a component is located in an electrostatic shielding space at least this separation distance from the radial periphery of the electrostatic shielding elements, the component is protected.

[0036] Alternatively, the electronic component is a sensor powered by and / or communicatively coupled to the electrical equipment.

[0037] Sensors located in electrostatically shielded spaces are exposed to an environment in which electrostatic shielding devices are positioned. Therefore, such sensors can measure properties such as temperature, pressure, and humidity without being exposed to an electric field and without risking field strengthening and / or dielectric breakdown of the dielectric in which such sensors are placed (which could lead to destructive arcing). The sensors can be powered by electrical devices inductively coupled to the magnetic field. Any sensor data can be wirelessly transmitted to a remote control unit via the electrical devices and the magnetic field. "Remote" will be understood herein as being away from or outside of an electric / magnetic field.

[0038] Optionally, the shielding space may include field-grading materials or dielectric materials.

[0039] Field-grading materials can be nonlinear resistive field-grading materials. A key characteristic of nonlinear resistive field-grading materials is their increased conductivity beyond a threshold electric field amplitude, which can therefore be used to reduce maximum field stress at locations within an insulating system. Field-grading material composites typically consist of a base polymer, such as SiR, ethylene propylene diene monomer rubber, epoxy resin, or thermoplastic, and may be filled with one or more fillers, often conductive or semi-conductive, to achieve nonlinear behavior. The nonlinear conductivity behavior of the composite originates from the semiconductor filler. The filler material can be silicon carbide, but alternatives exist.

[0040] Any suitable dielectric material can be used, such as cardboard, paper, cellulose or impregnated cellulose, dielectric polymers, etc. Fluid dielectric materials or supplementary solid dielectric materials can be used alternatively. Fluid dielectric materials can be exemplified by air, oil, etc. Field-grading materials or dielectric materials can partially or completely fill the shielding space.

[0041] According to a third aspect of this disclosure, this objective is achieved at least in part by means of a transformer device.

[0042] Therefore, a transformer device is provided, comprising a transformer and an electrostatic shielding device according to any one of the embodiments of the second aspect of this disclosure.

[0043] Electrostatic shielding devices can be installed in transformer units. They protect and power sensors used to monitor the transformer during operation. Due to the shielding properties of the electrostatic shielding elements, it is not necessary to disconnect the transformer for any sensor to perform measurements.

[0044] As will be apparent to those skilled in the art, the foregoing aspects and / or the examples disclosed herein above and hereinafter can be appropriately combined with each other.

[0045] Additional features and advantages are disclosed in the following description and drawings, and will be readily apparent to those skilled in the art or will be recognized by practice of the disclosure as described herein. Attached Figure Description

[0046] Further objects, advantages, and features of this disclosure will become apparent from the following description of one or more embodiments with reference to the accompanying drawings, in which: Figure 1 An example of an electrostatic shielding element according to the first aspect of this disclosure is shown.

[0047] Figure 2 An example of an electrostatic shielding element according to the first aspect of this disclosure is shown.

[0048] Figure 3 An example of an electrostatic shielding element according to the first aspect of this disclosure is shown.

[0049] Figure 4 An example of an electrostatic shielding element according to the first aspect of this disclosure is shown.

[0050] Figure 5 A graph showing exemplary experimental results is provided.

[0051] Figure 6 An example of an electrostatic shielding device according to the second aspect of this disclosure is shown.

[0052] Figure 7 An example of an electrostatic shielding device according to the second aspect of this disclosure is shown.

[0053] Figure 8 An example of a transformer device according to the third aspect of this disclosure is shown. Detailed Implementation

[0054] The present disclosure is explained in more detail below with reference to the accompanying drawings, which illustrate examples of embodiments. This disclosure should not be construed as limiting itself to the examples described. Throughout the specification, similar numerals refer to similar technical features.

[0055] The terminology used herein is for the purpose of describing specific aspects of this disclosure only and is not intended to limit the invention. As used herein, unless the context clearly indicates otherwise, the singular articles “a,” “an,” and “the” are intended to also include the plural forms. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0056] Figure 1An electrostatic shielding element 1 for protection against electric fields is shown. The electrostatic shielding element 1 is shown arranged along a first axis z, as viewed along the first axis z. The electrostatic shielding element 1 includes an electrostatic shielding volume 14 at least partially enclosed by a conductive coating 12, wherein the thickness d and conductivity σ of the coating 12 are selected such that a magnetic field of a predetermined frequency f can penetrate the coating and enter the volume 14. The volume 14 may extend laterally from the first axis z. The volume 14 may be disk-shaped, and its lateral extension from the first axis z is significantly larger than its lateral extension along the first axis z. Figure 1 As illustrated, volume 14 may be circular about a first axis z, having a radius r. For a single shielding element 1, the electrostatic shielding volume 14 may be completely enclosed by the conductive coating 12. If the open area of ​​the shielding volume 14 is covered by an adjacent current-connected conductor (such as another shielding element 1), the shielding volume 14 may be partially enclosed, i.e., partially open.

[0057] like Figure 2 As shown, volume 14 can alternatively be elliptical about the first axis z. The elliptical volume 14 may extend a first distance r1 along a second (major) axis x orthogonal to the first axis z. The elliptical volume 14 may also extend a second distance r2 along a third (minor) axis y orthogonal to both the first axis z and the second axis x. A circular or elliptical volume 14 about the first axis z is preferred because this is done to reduce the risk of field reinforcement at corners and edges.

[0058] Figure 3 and Figure 4 A side view of an electrostatic shielding element 1 according to a first aspect of this disclosure is shown. The electrostatic shielding element 1 is viewed along either the second axis x or the third axis y (i.e., perpendicular to the first axis z). Figure 3 In the middle, volume 14 has a slightly conical or parabolic shape around the first axis z, and in Figure 4 In this case, volume 14 is substantially flat around the first axis z. Both shapes are equally conceivable.

[0059] Furthermore, the radially outer periphery or edge 13 of volume 14 may have a circular shape in a plane parallel to the first axis z. The radius of curvature rc of the radially outer edge may preferably be half of the volume thickness t at the radially outer edge 13, as seen along the first axis z.

[0060] Figure 3 A detailed view of coating 12 is shown. The electrostatic shielding volume 14 is configured to be protected from electric fields at operating frequencies of 50 Hz / 60 Hz. For this purpose, the coating material needs to be sufficiently conductive. The coating material also needs to be continuous to completely enclose volume 14.

[0061] By appropriately selecting the conductivity σ and thickness d of the coating 12, the magnetic field can penetrate into the volume 14, thereby enabling power transmission and signal transmission to the electrical equipment included in the volume 14.

[0062] The coating 12 is preferably a conductive metal coating 12. When the coating 12 is exposed to an incident magnetic field, eddy currents are induced in the coating 12. The eddy current effect increases with the increase of the magnetic field frequency and prevents the magnetic field from penetrating the shielding volume. The eddy current effect decreases as the conductivity σ of the coating material decreases.

[0063] A thicker coating 12 requires a lower electrical conductivity σ than a thinner coating 12 to allow the magnetic field to penetrate into the volume 14. However, a thicker coating 12 has better mechanical strength than a thinner coating 12.

[0064] For a predetermined frequency f, the conductivity σ and thickness d of coating 12 can be selected such that:

[0065] Where c is a constant less than or equal to 40,000 Sm / s, this allows approximately 10% of the magnetic field signal power to penetrate the coating 12. Preferably, c is less than or equal to 5,000 Sm / s, resulting in approximately 50% of the signal power penetrating the coating 12. Most preferably, c is less than or equal to 1,000 Sm / s, thereby allowing 90% of the signal power to penetrate the coating 12.

[0066] The frequency f of the magnetic field used in power transmission and signal transmission applications is typically between 20 kHz and 20 MHz. Therefore, designing electrical equipment and electronic components for a predetermined frequency f within this range limits the range of selectable coating conductivity / materials and coating thicknesses.

[0067] The thickness of the conductive layer can be less than or equal to 1 mm.

[0068] The conductivity σ of the conductive layer (or coating) 12 is in the range of 1 S / m - 10. 8 Within the range of S / m, preferably within 10 3 S / m –10 8 Within the range of S / m, and most preferably within 10 5 S / m – 10 8 Within the range of S / m. Less than 10 8 The conductivity S / m range covers conductive materials such as metals. It is also conceivable to use materials with a conductivity of at least 10. 5 The coating of semiconductor materials with a ratio of S / m and materials with a ratio of approximately 1 S / m (such as carbon / graphite).

[0069] like Figure 3 and Figure 4As illustrated in the example, the electrostatic shielding element 1 includes at least one electrical device 18 enclosed within a volume 14. The electrical device 18 may be configured to receive power via inductive coupling and / or communicatively coupled to a magnetic field of a predetermined frequency f.

[0070] Electrical device 18 can be enclosed and electrostatically shielded within the coated volume 14. Electricity can be wirelessly received and transmitted to another electrical device 18 or component in an inductive manner. Additionally, electrical device 18 can be communicatively coupled to a magnetic field to receive signals from and / or transmit signals to receivers / transmitters (not shown) outside the electrostatically shielded volume via the magnetic field. Thus, the electrostatic shielding element 1 can be located in a high-voltage electric field without risking damage to the electrical device or surrounding instruments and / or equipment.

[0071] Electrical device 18 may include at least one LC circuit. The LC circuit may include a single LC circuit or multiple LC circuits (such as an array of LC circuits). Electrical device 18, which receives power from a magnetic field and is capable of performing wireless power transmission and signal transmission, is a conventional device not described in detail in this disclosure.

[0072] Figure 5 The simulation results show the variation of the magnetic field penetration into volume 14. The vertical axis represents the degree to which the magnetic field penetrates coating 12 into volume 14. A value of 1 indicates very good penetration, and a value of 0 indicates no penetration. The horizontal axis is the product fσ. Three examples are shown for different coating thicknesses d1, d2, and d3, where d1 = 100 µm, d2 = 10 µm, and d3 = 1 µm.

[0073] As illustrated in the simulation example, for the case of d2, when the frequency f * conductivity σ is less than 10... 13 At that time, the magnetic field almost completely penetrated coating 12, and when the product exceeded 10... 15 At that time, the magnetic field was almost completely blocked. At 10... 13 <Frequency f × Conductivity σ<10 15 Within this range, varying degrees of magnetic field penetration exist. Therefore, for a predetermined frequency f of 1 MHz used to ensure complete magnetic field penetration through the 10 µm thick coating 12, it must be ensured that:

[0074] Figure 6 An electrostatic shielding device 2 according to a second aspect of the present disclosure is shown. The electrostatic shielding device 2 includes at least two electrostatic shielding elements 1 according to any of the examples described above. The electrostatic shielding elements 1 are electrically connected to each other, and the at least two electrostatic shielding elements 1 are arranged spaced apart from each other along a first axis z, thereby forming an electrostatic shielding space 16 between the at least two electrostatic shielding elements 1.

[0075] The current connection between at least two electrostatic shielding elements 1 ensures an equipotential surface across the entire surface of the electrostatic shielding device 2, which further ensures that the potential in the shielding space 16 is negligible. Both of them are arranged on the first axis z, for example, parallel to each other along the first axis z. Therefore, the electrostatic shielding space 16 between the electrostatic shielding elements 1 also extends laterally to the ground from the first axis z. The shielding space 16 may include any components that need to be shielded from the effects of electric fields but need to be in contact with the environment outside the electrostatic shielding elements 1 (i.e., the environment in which the electrostatic shielding device 2 is placed).

[0076] At least two electrostatic shielding elements may be mechanically and electrically connected to each other via at least one conductive fixing element.

[0077] The current connection can be achieved by a conductive fixing element 20 (such as a screw or bolt) that engages at least two electrostatic shielding elements 1. The fixing element 20 can also be made conductive by a conductive coating (such as a coating 12 identical to that of the at least two electrostatic shielding elements 1). The electrostatic shielding device 2 may include at least one electronic component 22 disposed in the electrostatic shielding space 16, and the electrical device 18 may be electrically connected to the electronic component 22.

[0078] Electronic component 22 may be located within electrostatic shielding space 16 without risking interference from electric fields outside electrostatic shielding device 2. Electrical component 22 may be electrically connected to electrical device 18, located inside electrostatic shielding element 1, via an electrical conductor 26 passing through coating 12 of electrostatic shielding element 1 (passing through the wall of electrostatic shielding element that borders electrostatic shielding space 16). Alternatively, electrical component 22 may be wirelessly connected to electrical device, such as if electrical component 22 is inductively coupled to electrical device. In this example, electrical component 22 may include at least one LC circuit.

[0079] At least two electrostatic shielding elements 1 may be spaced apart from each other by a separation distance D. Electronic components 22 may be located within the shielding space 16 at this separation distance D, at least from the radial peripheries 13 of the at least two electrostatic shielding elements 1. Typically, the separation distance is defined as the distance between the radial peripheries 13 of the electrostatic shielding elements 1 along a first axis z. The separation distance D is preferably significantly smaller than the radii r, r1, r2 of the electrostatic shielding elements 1. As an example, the separation distance D is less than or equal to one-fifth of the radii r, r1, r2. In the case of elliptical electrostatic shielding elements, the separation distance is determined with respect to the extension along the minor axis of the elliptical body (i.e., along the third axis y).

[0080] The distance between at least two electrostatic shielding elements 1 can vary throughout the shielding space. By rule of thumb, the electric field is negligible at such a distance, i.e., this distance is equal to the separation distance D from the radial periphery 13 of the at least two electrostatic shielding elements 1. Therefore, if the electronic component 22 is located within the electrostatic shielding space 16 and at least at this separation distance from the radial periphery of the electrostatic shielding elements, then the electronic component 22 is protected. The shielding space 16 is composed of… Figure 7 The dashed lines in the diagram define and illustrate the area.

[0081] Electronic component 22 may be a sensor 22 powered and / or communicatively coupled to electrical device 18.

[0082] The sensor 22, located in the electrostatically shielded space 16, is exposed to the environment in which the electrostatic shielding device 2 is positioned. Therefore, such a sensor can measure properties such as temperature, pressure, and humidity without being exposed to an electric field and without risking field strengthening and / or dielectric breakdown of the dielectric in which such a sensor is placed (which could lead to destructive arcing). The sensor 22 can be powered by an electrical device 18 inductively coupled to the magnetic field.

[0083] The shielding space 16 includes a field-grading material or a dielectric material. The field-grading material can be a nonlinear resistive field-grading material. A key characteristic of nonlinear resistive field-grading materials is their increased conductivity beyond a threshold electric field amplitude, which can therefore be used to reduce the maximum field stress at locations within the insulation system. Field-grading material composites typically consist of a base polymer, such as SiR, ethylene propylene diene monomer rubber, epoxy resin, or thermoplastic, and may be filled with one or more fillers, often conductive or semi-conductive, to achieve nonlinear behavior. The nonlinear conductivity behavior of the composite originates from the semiconductor filler. The filler material can be silicon carbide, but alternatives exist.

[0084] Any suitable dielectric material can be used, such as cardboard, paper, cellulose or impregnated cellulose, dielectric polymers, etc. Fluid dielectric materials or supplementary solid dielectric materials can be used alternatively. Fluid dielectric materials can be exemplified by air, oil, etc. Field-grading materials or dielectric materials can partially or completely fill the shielding space 16.

[0085] Figure 8 A transformer device 3 according to a third aspect of this disclosure is conceptually illustrated. The transformer device 3 includes a transformer 24 and an electrostatic shielding device 2 according to any of the examples described above. Therefore, the electrostatic shielding device 2 can be disposed within the transformer device 3. The electrostatic shielding device 2 can protect and drive the sensor 22 to monitor the transformer 24 during operation. Due to the shielding nature of the electrostatic shielding element 1, it is not necessary to disconnect the transformer 24 for any sensor to perform measurements.

[0086] Any transformer device 3 may include a monitoring unit 28 and may be configured such that electronic components 22 are wirelessly coupled to control unit 28 via electrical device 18 and via magnetic field. Control unit 28 may be configured to transmit power to electrical device 18 via magnetic field and receive signals (e.g., sensor data) from electronic components 22 via electrical device 18 via magnetic field.

Claims

1. An electrostatic shielding device (2) for high-voltage electric field applications, the electrostatic shielding device (2) comprising: At least two electrostatic shielding elements (1) are arranged on a first axis (z), each electrostatic shielding element comprising an electrostatic shielding volume (14) at least partially enclosed by a conductive coating (12) of the shielding element (1), wherein the thickness (d) and conductivity (σ) of the coating (12) are selected such that a magnetic field of a predetermined frequency (f) can penetrate the coating into the volume (14), and Wherein, for the predetermined frequency (f), the conductivity (σ) and thickness (d) of the coating (12) are selected such that: Where c is a constant, and c ≤ 40,000 Sm / s, and The electrostatic shielding elements (1) are electrically connected to each other, and the at least two electrostatic shielding elements (1) are arranged along the first axis (z) at a distance (D) from each other, thereby forming a partially open electrostatic shielding space (16) between the at least two electrostatic shielding elements (1). The volume (14) extends laterally from the first axis (z). Wherein, the volume (14) is circular or elliptical about the first axis (z), and wherein the circular volume (14) has a radius (r) extending orthogonally from the first axis (z), and the separation distance (D) is less than or equal to one-fifth of the radius (r). Furthermore, the elliptical volume (14) extends a first distance (r1) along a second axis (x) orthogonal to the first axis (z) and a second distance (r2) along a third axis (y) orthogonal to both the first axis (z) and the second axis (x), wherein the separation distance (D) is less than or equal to one-fifth of the smaller of the first distance (r1) and the second distance (r2).

2. The electrostatic shielding device (2) according to any one of claims 1, wherein, The thickness (d) of the coating (12) is less than or equal to 1 mm.

3. The electrostatic shielding device (2) according to any one of claims 1 or 2, wherein, The electrical conductivity (σ) of the coating (12) is in the range of 1 S / m - 10. 8 Within the range of S / m.

4. The electrostatic shielding device (2) according to claim 1, wherein the electrostatic shielding device (2) comprises at least one electrical device (18) enclosed within the volume (14), wherein, The electrical device (18) is configured to receive power via inductive coupling and / or communicatively couple to a magnetic field at the predetermined frequency (f).

5. The electrostatic shielding device (2) according to claim 4, wherein, The electrical equipment (18) includes at least one LC circuit.

6. The electrostatic shielding device (2) according to claim 1, wherein, The at least two electrostatic shielding elements (1) are mechanically and electrically connected to each other via at least one conductive fixing element (20).

7. The electrostatic shielding device (2) according to claim 4 or 5, wherein the electrostatic shielding device (2) includes at least one electronic component (22) arranged in the electrostatic shielding space (16), and wherein, The electrical equipment (18) is electrically connected to the electronic component (22).

8. The electrostatic shielding device (2) according to claim 7, wherein, The at least two electrostatic shielding elements (1) are at least spaced apart from each other by a separation distance (D), and the electronic component (22) is located in the shielding space (16) at at least the separation distance (D) from the radial periphery (13) of the at least two electrostatic shielding elements (1).

9. The electrostatic shielding device (2) according to claim 7, wherein, The electronic component is a sensor powered and / or communicatively coupled to the electrical device (18).

10. The electrostatic shielding device (2) according to claim 9, wherein, The sensor is a temperature sensor, a pressure sensor, or a humidity sensor.

11. The electrostatic shielding device (2) according to claim 1, wherein, The shielding space includes field-grading materials or dielectric materials.

12. A transformer device (3), the transformer device (3) comprising a transformer (24) and an electrostatic shielding device according to any one of claims 1 to 11.

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