Housing

Abstract

The present disclosure relates to an enclosure for an electrical device in a high voltage electric field, the enclosure comprising at least one top element and at least one corresponding bottom element extending circumferentially from a central portion, where the top element and the bottom element are plate-like elements, the top element and the bottom element are disposed substantially parallel to each other at a predetermined distance to provide a space therebetween. The top element and the bottom element are each electrically connected at one end of the central portion and electrically contacted at a respective circumferential end to form at least a portion of the housing. The housing is at least partially composed of an electrically conductive material. At least two slots are disposed in the housing, the at least two slots extending from the central portion to the periphery to separate different portions of the housing.

Description

Technical Field

[0001] The present disclosure relates to a housing for an electrical device in a high voltage electric field, and in particular to a multifunctional shielding housing for a wireless device in a high voltage environment. Background Art

[0002] The use of wireless transmission of data and power in high voltage facilities is increasing due to the introduction of more sensors and remote control systems. Often, this involves placing a small device containing electronic devices and a radio transmitter or receiver in a very harsh electromagnetic environment. Some examples may include power transformers, substations, and HVDC converter stations. In particular, excessively high electric fields may interfere with electronic devices or cause partial discharges to occur due to field enhancement at the surface of the inserted device. Therefore, it is necessary to perform some field grading and electrical shielding on the electronic devices. However, complete shielding cannot be expected because wireless power transmission is required to the electronic devices when the wires cannot be used in a strong electric field environment. Therefore, the shielding housing must be able to penetrate the magnetic field used for power transmission. An additional problem is to design an antenna that allows high-frequency data communication to and from the device. Placing the antenna element outside the shielding housing will inevitably increase the risk of strong field enhancement and therefore partial discharge. Summary of the invention

[0003] Therefore, at least one of the following requirements needs to be met:

[0004] - Highly efficient shielding of external (e.g. 50 / 60 Hz) AC electric fields while minimizing field enhancement just outside the housing.

[0005] - Allowing an externally applied magnetic field for wireless power transfer (eg, typical frequencies in the MHz range) to reach the interior of the housing where the pick-up coil is placed.

[0006] - Has a design such that the housing itself can also be used as an antenna element for high frequency (eg GHz range) data communications.

[0007] The present disclosure relates to a housing.

[0008] Various exemplary embodiments of the housing disclosed herein are directed to providing features that will become apparent by reference to the following description when taken in conjunction with the accompanying drawings. According to various embodiments, exemplary systems, methods, and devices are disclosed herein. However, it should be understood that these embodiments are presented by way of example and not limitation, and it will be apparent to those of ordinary skill in the art reading this disclosure that various modifications may be made to the disclosed embodiments within the scope of this disclosure.

[0009] Therefore, the present disclosure is not limited to the exemplary embodiments and applications described and illustrated herein. Additionally, the specific order and / or hierarchy of steps in the methods disclosed herein are merely exemplary methods. Based on design preferences, the specific order or hierarchy of steps of the disclosed methods or processes can be rearranged within the scope of the present disclosure. Therefore, it will be understood by those of ordinary skill in the art that the methods and techniques disclosed herein present various steps or behaviors in a sample order, and unless otherwise expressly stated, the present disclosure is not limited to the specific order or hierarchy presented.

[0010] The above and other aspects and embodiments thereof are described in more detail in the drawings, the description and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 shows a perspective view of an example of a housing according to the present disclosure,

[0012] Figure 2 shows a plan view of an example of a housing according to the present disclosure, the housing including an antenna feed circuit,

[0013] Figure 3 shows the normalized electric field amplitude in the electric field in an exemplary housing according to the present disclosure,

[0014] Figure 4 shows the normalized magnetic field component of the electric field in an exemplary housing according to the present disclosure, and

[0015] Figures 5 to 7 Shown according to Figure 2 Radiation patterns of the enclosure in three corresponding planes. DETAILED DESCRIPTION

[0016] In the following, exemplary embodiments of the present disclosure will be described. It should be noted that, unless otherwise stated or apparent, some aspects of any one of the described embodiments may also be found in some other embodiments. However, in order to improve understandability, each aspect will be described in detail only when first mentioned, and any repeated description of the same aspect will be omitted.

[0017] The present disclosure relates to a housing for an electrical device in a high voltage electric field, the housing comprising at least one top element and at least one corresponding bottom element extending circumferentially from a central portion, wherein the top element and the bottom element are plate-like elements, and the top element and the bottom element are arranged substantially parallel to each other at a predetermined distance to provide a space therebetween. The top element and the bottom element are each electrically connected at one end of the central portion and electrically contacted at the corresponding circumferential end to form at least a portion of the housing. The housing is at least partially composed of a conductive material. At least two slots are arranged in the housing, and the aforementioned at least two slots extend from the central portion to the periphery to separate different parts of the housing.

[0018] Various embodiments may particularly implement the following features.

[0019] The top element and the bottom element may be configured to be oriented substantially perpendicular to the direction of the electric field.

[0020] The housing may be configured to allow wireless power transfer to space.

[0021] The housing may be divided into two parts at a central portion.An antenna feed circuit may be connected to the two parts of the housing.

[0022] The top element and the bottom element can be connected by a connecting portion at the periphery of the top element and the bottom element. In particular, the top element, the bottom and the connecting portion are integrally formed.

[0023] The slots may be arranged symmetrically with respect to the central portion.

[0024] The top element and the bottom element forming this part of the shell can form a fan around the central part. The radius of the top element and the bottom element can be particularly between 5mm and 75mm. The distance between the top element and the bottom element can be particularly between 5mm and 15mm.

[0025] The top member, the bottom member, and the connecting portion may each include a certain thickness and a certain conductivity.

[0026] The space may be at least partially filled with dielectric and insulating materials.

[0027] An opening may be provided in the housing to enable insertion of the electronic device.

[0028] The housing may include a conductive layer.

[0029] The width of the groove at the periphery of the housing may be less than 25% of the distance between the top element and the bottom element.

[0030] The distance between the grooves at the periphery of the housing may be equal to or less than the distance between the top element and the bottom element.

[0031] The width of the groove may gradually increase from the central portion toward the periphery.

[0032] In the following it is assumed that the main direction of the AC electric field of the power transformer, substation, HVDC converter station etc. is well known so that the plane of the housing can be oriented substantially perpendicular to the electric field. In this way, the field enhancement at the surface of the housing will be minimized.

[0033] Figure 1An exemplary housing according to the present disclosure is shown. The housing 1 includes at least one top element 2 and at least one corresponding bottom element 3 extending circumferentially from a central portion 6. The top element 2 and the bottom element 3 are plate-like elements, and the top element 2 and the bottom element 3 are arranged substantially parallel to each other at a predetermined distance to provide a space therebetween. The top element 2 and the bottom element 3 are each electrically connected at one end at the central portion 6, and are electrically contacted at the corresponding circumferential ends to form at least a portion of the housing 1. However, it is not necessary for the top element 2 and the bottom element 3 to contact each other at the central portion 6. In other words, at the central portion, there may be no direct connection between the top element 2 and the bottom element 3. The housing 1 is at least partially composed of a conductive material. At least two grooves 5 are provided in the housing 1, and the aforementioned at least two grooves extend from the central portion 6 to the periphery to separate different parts of the housing 1. In Figure 1 In FIG. 1 , E0 indicates the direction of the electric field. The overall shape of the housing 1 can be described as a flat medicine box shape.

[0034] The top member 2 and the bottom member 3 may be connected by connection portions 4 at the peripheries of the top member 2 and the bottom member 3, respectively. The top member 2, the bottom member 3, and the connection portions 4 may be integrally formed.

[0035] In other words, a housing 1 for an electrical device in a high voltage electric field may include a top element 2 and a bottom element 3 having a circular shape, wherein the top element 2 and the bottom element 3 are plate-like elements arranged parallel to each other. The top element 2 and the bottom element 3 may be connected by connecting portions 4 at the peripheries of the top element 2 and the bottom element 3, respectively, to provide a space therebetween and form the housing 1. The housing 1 may be at least partially composed of a conductive material, and at least two grooves 5 from a central portion 6 to a periphery may be provided in the housing 1 to form portions or segments of the housing 1, wherein the central portions 6 of the top element 2 and the bottom element 3 electrically connect the portions.

[0036] The overall shape of the housing 1 may in particular be curved or rounded, such as an elliptical or circular shape, to avoid sharp corners that adversely affect the shielding performance.

[0037] In particular, in use, the top element 2 and the bottom element 3 can be configured to be oriented substantially perpendicular to the direction of the electric field. Thus, electrical shielding of the space can be achieved. In addition, the housing 1 can be configured to allow wireless power transmission to the space inside the housing 1.

[0038] Even for other relative orientations of the housing 1 and the electric field, electrical shielding of the interior space of the housing 1 is achieved. However, if they are not perpendicular to each other, significant field enhancement may occur at the outer surface of the housing.

[0039] The top element 2, the bottom element 3 and the connecting portion 4 may each comprise a certain thickness d and a certain conductivity σ, wherein the product of the thickness d and the conductivity σ is in particular less than 5. 1 / Ω, that is, 5S. In principle, as long as the product σd is large enough, σd>10 -9 S, the electric field attenuation inside the housing 1 (i.e., the Faraday cage effect) is not affected by the orientation. However, the field enhancement just outside the housing surface is affected by the aforementioned orientation. If this field enhancement is too large, this may cause partial discharges to occur there. By orienting the housing so that the external electric field is perpendicular to the flat surface of the housing, the field enhancement is minimized.

[0040] An opening may be provided in the housing 1 to enable the electronic device to be inserted. The electronic device may, for example, be configured to provide operating data or control signals to or to a power transformer, a substation, an HVDC converter station, etc. to which the housing 1 is attached or near which the housing is located.

[0041] The housing 1 can be divided into two parts at the central portion 6, such as Figure 2 An antenna feed circuit 7 may be connected to both parts of the housing 1. In this way, the housing may additionally operate as an antenna for communicating, for example, operating data or control signals of a power transformer, a substation, a HVDC converter station from an electronic device via the housing 1.

[0042] Moreover, if Figure 2 The presence of a gap shown in , where the antenna feed circuit 7 is mounted (required to achieve GHz antenna functionality) requires that the planar surfaces of the top element 2 and the bottom element 3 are perpendicular to the electric field. For other orientations, strong electric fields may exist in the gap region.

[0043] The grooves 5 may be arranged symmetrically with respect to the central portion 6. The top element 2 and the bottom element 3 forming this part of the housing 1 may form a sector around the central portion 6. In an example, the radius of the top element 2 and the bottom element 3 is between 5 mm and 75 mm. Assuming that the housing 1 is circular, its diameter may be between 10 mm and 150 mm. In an example, the distance between the top element 2 and the bottom element 3 is between 5 mm and 15 mm.

[0044] The space, ie the space between the top element 2 and the bottom element 3 , may be at least partially filled with dielectric and insulating material.

[0045] The housing 1 may include a conductive layer. That is, the housing 1 may be coated with a conductive layer.

[0046] In the example, the width of the grooves 5 at the periphery of the housing is less than 25% of the distance between the top element 2 and the bottom element 3. In the example, the distance between the grooves 5 at the periphery of the housing is equal to or less than the distance between the top element 2 and the bottom element 3.

[0047] The width of the groove 5 may gradually increase from the central portion 6 toward the periphery.

[0048] refer to Figure 1 and Figure 2 The exemplary housing 1 described will be explained in more detail with respect to the requirements mentioned above. The diameter of the (pill box-shaped, i.e. circular) housing 1 forming the basis for the following simulations and calculations is 100 mm and the thickness is 10 mm. Typically, the diameter is in the range of 10 mm to 150 mm, and the thickness varies between 5 mm and 15 mm. The electronic device is positioned in the interior of the housing, which is filled with dielectric and insulating materials to provide mechanical support for the conductive housing layer. However, the nature of the above values ​​and ranges is only exemplary, and the present disclosure is not limited thereto.

[0049] The following is about the electrical shielding of the interior. Low-frequency electrical shielding of the interior can be achieved by using a Faraday cage type conductive housing 1. Figure 1 In the illustrated example shown in , the cage of the housing 1 consists of a thin conductive layer partially covering the surface of the housing 1. Here, the product of the layer conductivity σ and the thickness d must be large enough to reduce the electric field level inside the housing 1 to an acceptable level. Typically, σd should be greater than 10 -9 S(10 -9 1 / Ω ). In addition, the product σd should be less than 5S (i.e., 5 1 / Ω ), in particular less than 1 S. A small layer surface (i.e. the central portion 6 close to the axis of symmetry) electrically connects different parts of the housing 1 (i.e. the top element 2 and the bottom element 3, respectively), which further improves the shielding of non-axial electric field components and provides a certain mechanical stability.

[0050] Figure 3 The shielding effect of the housing 1 is illustrated. In this simulation, an external electric field of E0 = 1 V / m was assumed. Even with relatively low values ​​of the layer conductivity σ, significant shielding is obtained. It can also be seen that the shielding efficiency is not uniform inside the housing 1. In particular, Figure 3 A graph of the electric field amplitude along two radial lines in the horizontal plane, respectively below the conductive layer (i.e. between the top element 2 and the bottom element 3) and below the slot 5 is shown. In particular, the graph shows the normalized electric field amplitude (V / m) depending on the radius r (m) below the slot (continuous line) and below the layer (i.e. the part as explained above) (dashed line).

[0051] As can be seen from the graph, the exemplary housing 1 provides a significant reduction in the electric field, particularly not only below the portions but also within the slots.

[0052] The following are requirements for allowing a magnetic field to pass through to the space inside the housing 1 in order to provide wireless power transmission.

[0053] The efficiency of wireless power transfer can be optimized when (i) the applied magnetic field is perpendicular to the plane of the pickup coil, and (ii) the area of ​​the planar pickup coil (e.g., of an electronic device placed inside the housing 1 and requiring power) is as large as possible. These two conditions are met when the internal pickup coil is in the plane of the housing 1 and the magnetic field is perpendicular to the same plane. In our case, this implies that optimized power transfer is obtained when the applied magnetic field is parallel to a strong external electric field.

[0054] However, due to the shielding effect of the induced current in the conductive shell layer, the amplitude of the magnetic field inside the shell will be reduced. Therefore, in order to achieve efficient power transmission, the generation of induced current must be offset in some way. As described above, one way to accomplish this is to cut slots 5 in the conductive shell 1 layer. By orienting the slots 5 to be perpendicular to the direction of the original induced current everywhere, the amplitude of these currents and the damping of the magnetic field will be sharply reduced. In the case of a pillbox-shaped shell 1 without slots, the induced current will circulate in an angular direction around the axis of symmetry of the shell (the axis of symmetry is parallel to the imposed magnetic field). Therefore, radial slots 5 are introduced to hinder the induced current and thus allow the magnetic field to penetrate the shell 1 (the small surface close to the axis of symmetry, i.e., the central portion 6, will not have a significant effect). Figure 1 and Figure 2 The example design in illustrates how such slots can be introduced into the housing layer. Note that these slots do not disrupt the electrical connection between the upper and lower planar surfaces of the housing 1. This is very important for making the electrical shielding work as outlined above.

[0055] exist Figure 4 In the simulation shown in , it is assumed that the imposed vertical magnetic field has an amplitude |H z |=1 A / m and oscillates at a frequency of f=13 MHz. Likewise, the product of layer thickness and conductivity is σd=5S. Figure 4 The vertical component of the magnetic field in a horizontal plane passing through the center of the housing 1 is shown along two radial lines. Figure 4 The graph of shows the normalized magnetic field over the radius, where the continuous line shows the magnetic field below the slot 5 and the dashed line shows the magnetic field below the layers (ie the parts). The overall damping is shown to be suitable for wireless power transmission.

[0056] The following are requirements for providing antenna functionality. Since the housing 1 layer is conductive, it can be used as an antenna element. The simplest way to achieve this is to make it an electric dipole radiator. This is done by cutting the (pillbox shaped) housing 1 into two halves at the central portion 6 and connecting these halves in the central portion 6 via the antenna feed circuit 7, as shown in FIG. Figure 2 As shown in and explained above. This will produce a dipole antenna connected to the feed circuit 7. For wavelengths longer than the size of the housing 1 (i.e. the diameter in this example), the radiated power will be distributed omnidirectionally, except in directions close to the direction of the dipole moment. At shorter wavelengths, a significant directional dependence will occur.

[0057] It should be noted that the gaps created when segmenting the housing 1 have no influence on the desired electrical shielding and magnetic field penetration.

[0058] In the above example, if Figure 2 As shown in , by cutting through the central portion 6, two halves are created. The antenna feed circuit 7 between the two halves is oriented in the y direction, which will also be the direction of the antenna dipole moment. Solving for the near field and then performing a near field to far field transformation produces Figures 5 to 7 The radiation pattern shown in . Again, for the simulations, σd=5S is assumed. The frequency is assumed to be 2.4 GHz. The quantity shown is the radiated power (in dB), i.e., the radiated power density as a function of direction. It is observed that the radiated power is distributed fairly uniformly, except in the direction of the antenna dipole moment (i.e., along the y-axis).

[0059] Figures 5 to 7 shows the radiated power plotted in the xy plane ( Figure 5 )、xz plane( Figure 6 ) and the yz plane ( Figure 7 ) in a two-dimensional graph.

[0060] According to the present disclosure, it is possible to design a housing that will strongly suppress external electric fields while allowing magnetic fields for wireless power transmission to penetrate. In addition, the housing can be used as an element of a dipole antenna for communicating with an external device. Through careful design, these three functions can be introduced without interfering with each other. Therefore, the features and functions mentioned above can be combined in a compact design, the housing can be used for a wide frequency range, and a very robust product can be provided in terms of electrical, thermal and mechanical properties.

[0061] Although various embodiments of the present disclosure have been described above, it should be understood that these embodiments are presented only by way of example and not by way of limitation. Similarly, various figures may depict example architectures or configurations, which are provided to enable those of ordinary skill in the art to understand the exemplary features and functions of the present disclosure. However, such personnel will understand that the present disclosure is not limited to the illustrated example architectures or configurations, but may be implemented using various alternative architectures and configurations. Additionally, as will be understood by those of ordinary skill in the art, one or more features of an embodiment may be combined with one or more features of another embodiment described herein. Therefore, the breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments.

[0062] It should also be understood that any reference to an element using names such as "first," "second," etc. herein generally does not limit the quantity or order of those elements. Instead, these names may be used herein as a convenient means of distinguishing two or more elements or element instances. Thus, reference to a first and a second element does not mean that only two elements can be used, or that the first element must precede the second element in some manner.

[0063] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single unit may fulfill the functions of several features recited in the claims. The terms "substantially", "about", "approximately" etc. regarding an attribute or a value particularly also precisely define the attribute or precisely define the value, respectively. Any reference signs in the claims shall not be construed as limiting the scope.

Claims

1. A housing (1) for an electrical device in a high voltage electric field, the housing (1) include: at least one top element (2) and at least one corresponding bottom element (3) extending circumferentially from a central portion (6), wherein the top element (2) and the bottom element (3) are plate-like elements, the top element (2) and the bottom element (3) being arranged substantially parallel to each other at a predetermined distance to provide a space therebetween, wherein the top element (2) and the bottom element (3) are each electrically connected at one end of the central portion (6) and are electrically contacted at respective circumferential ends to form at least a portion of the housing (1); wherein the housing (1) is at least partially made of a conductive material; and At least two grooves (5) are provided in the housing (1), and the at least two grooves extend from the central part (6) to the periphery to separate different parts of the housing (1).

2. The housing (1) according to claim 1, in, The top element (2) and the bottom element (3) are configured to be oriented substantially perpendicular to the direction of the electric field.

3. The housing (1) according to claim 1 or 2, in, The housing (1) is configured to allow wireless power transmission to the space.

4. Housing (1) according to any one of the preceding claims, in, The housing (1) is divided into two parts at the central part (6), and Therein, an antenna feeding circuit is connected to two parts of the housing (1).

5. Housing (1) according to any one of the preceding claims, in, The top element (2) and the bottom element (3) are connected by a connecting portion (4) at the periphery of the top element and the bottom element (3), In particular, the top element (2), the bottom element (3) and the connecting portion (4) are formed integrally.

6. Housing (1) according to any one of the preceding claims, in, The grooves (5) are arranged symmetrically with respect to the central portion (6).

7. Housing (1) according to any one of the preceding claims, in, The top element (2) and the bottom element (3) forming part of the housing (1) form a sector around the central portion (6), wherein the radius of the top element (2) and the bottom element (3) is in particular between 5 mm and 75 mm, and / or Therein, the distance between the top element (2) and the bottom element (3) is in particular between 5 mm and 15 mm.

8. Housing (1) according to any one of the preceding claims, in, The top element (2), the bottom element (3) and the connecting portion (4) respectively comprise a certain thickness and a certain electrical conductivity.

9. Housing (1) according to any one of the preceding claims, in, The space is at least partially filled with dielectric and insulating material.

10. Housing (1) according to any one of the preceding claims, in, An opening is provided in the housing (1) to enable insertion of an electronic device.

11. Housing (1) according to any one of the preceding claims, in, The housing (1) comprises a conductive layer.

12. Housing (1) according to any one of the preceding claims, in, The width of the groove (5) at the periphery of the housing is less than 25% of the distance between the top element (2) and the bottom element (3).

13. Housing (1) according to any one of the preceding claims, in, The distance between the grooves (5) at the periphery of the housing is equal to or smaller than the distance between the top element (2) and the bottom element (3).

14. Housing (1) according to any one of the preceding claims, in, The width of the groove (5) gradually increases from the central portion (6) toward the periphery.

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