Metal enclosure for electrical switchgear
The metal enclosure with corrugated walls and reinforcements addresses the challenge of withstanding higher pressures in gas insulated switchgear, enabling compact and cost-effective operation with N2 and CO2 gases.
Patent Information
- Application Number
- CN202410809434.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-06-30
- Filing Date
- 2024-06-21
- Publication Date
- 2024-12-31
AI Technical Summary
Conventional metal enclosures for gas insulated switchgear struggle to withstand higher pressures required by alternative dielectric gases like N2, CO2, or their mixtures without increasing size or cost, necessitating bulky and expensive designs.
A metal enclosure with corrugated walls and slender metal elements and reinforcements, anchored by elongated metal elements and reinforcements, enhances pressure resistance without increasing size, suitable for pressures up to 4.0 bar absolute.
The solution allows the metal enclosure to withstand higher pressures, maintaining compact size and cost-effectiveness, suitable for high-voltage applications with gases like N2 and CO2, passing relevant pressure tests without needing oversized designs.
Smart Images
Figure CN119231361A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a metal enclosure for an electrical switching device. Background Art
[0002] The metal enclosure used for gas insulated switchgear encloses the switchgear in a pressurized environment. A gas is selected to provide electrical insulation inside the metal enclosure, a common gas is SF6, but other gases are also available, such as dry air, N2, CO2, or a mixture of two or three of N2, O2, CO2.
[0003] The dielectric resistance of the gas is proportional to the pressure inside the metal capsule. Therefore, it is advantageous to increase the pressure of the gas inside the metal capsule. However, this means that the metal capsule wall must be able to withstand the forces generated by the increased pressure.
[0004] Therefore, it is desirable to increase the ability of metal enclosures for gas insulated switchgear to withstand higher pressures, as explained in detail below. Summary of the invention
[0005] In view of the above and other shortcomings of the prior art, an object of the present invention is to provide a metal enclosure that at least partially alleviates the deficiencies of the prior art.
[0006] According to a first aspect of the present invention, a metal enclosure for an electrical switching device is provided, the metal enclosure being configured to be pressurized to a pressure higher than atmospheric pressure, the metal enclosure comprising: a metal wall sealing a volume space for accommodating the electrical switching device, the metal wall comprising a first metal wall, the first metal wall being arranged opposite to a second metal wall, wherein at least the second metal wall is a corrugated metal plate having corrugations extending along a first axis; a group of slender metal elements attached to the first metal wall and the second metal wall, the slender metal elements being arranged through holes in the first metal wall and the second metal wall and reaching the outside of the metal enclosure; a group of slender metal reinforcements attached to the back of the second metal wall on the outside of the metal enclosure, each metal reinforcement being attached to at least two corrugations of the second metal wall, wherein each metal reinforcement is attached to at least one slender metal element.
[0007] The invention is based at least in part on the realization of an elongated metal element that reaches between the first and second oppositely arranged metal walls and is attached to an elongated metal reinforcement on the back side of the second metal wall. Thus, the elongated metal elements penetrate the second metal wall so that they can be attached to the reinforcement outside the metal enclosure. The connection between the oppositely arranged walls provided by the elongated metal element increases the pressure resistance of the metal enclosure, and the connection to the reinforcement distributes the forces to the corrugations of the walls.
[0008] Tolerating higher pressures is particularly important when switching to dry air, N2, CO2, or a mixture of any two or three of these as dielectric gases. These gases require higher pressures to provide adequate insulation without increasing the distances between phases and components of the switchgear compared to the more environmentally unfriendly alternative gases such as SF6. Despite the switch to a different gas, it is desirable to maintain the size of the metal enclosure, or at least not increase it.
[0009] Generally speaking, in electrification and gas-insulated switchgear (GIS), if the gas pressure in a metal enclosure exceeds 1.5 bar absolute pressure, the enclosure can be called a high-voltage enclosure according to known standards. If so, it must pass the relevant pressure routine tests, which makes conventional enclosures bulky and quite expensive. Therefore, the filling pressure of the medium voltage (MV)-GIS discussed herein is typically <1.5 bar absolute pressure, for example, in the range of 1.0-1.5 bar absolute pressure. Advantageously, the metal enclosure disclosed herein is suitable for a filling pressure of 1.0-4.0 bar absolute pressure, preferably for a filling pressure of 1.5-3.0 bar absolute pressure. In other words, the pressure is increased compared to the traditional 1.0-1.5 bar absolute pressure range without the need for bulky and oversized enclosure walls.
[0010] According to one embodiment, each metal reinforcement may be attached to all the corrugations of the second metal wall, which further improves the pressure resistance of the metal enclosure.
[0011] According to one embodiment, the metal reinforcement may be an elongated plate arranged along an axis at an angle to the axis of the corrugation. The corrugations generally have a longitudinal axis along the valley or ridge of the corrugation. To further increase the pressure resistance, the main axis of the elongated metal reinforcement may be at an angle to the axis of the corrugation. The angle is such that the metal reinforcement is not parallel to the axis of the corrugation.
[0012] According to one embodiment, the angle may be approximately 90°.
[0013] According to one embodiment, the elongated metal element may be attached to the back side of the second metal wall and to the back side of the first metal wall.Distributing the forces to the back side where the reinforcement is located further improves the pressure resistance of the metal enclosure.
[0014] According to one embodiment, the elongated metal element may be attached to the first metal wall and the second metal wall by welding. Welding may firmly anchor the elongated metal element to the metal walls.
[0015] According to one embodiment, the metal reinforcement can be attached to the second metal wall by welding. Welding can firmly anchor the metal reinforcement to the metal wall.
[0016] According to one embodiment, the metal enclosure may include a set of elongated metal reinforcements attached to the back side of the first metal wall outside the metal enclosure, each metal reinforcement being attached to at least one elongated metal element. Using more than one metal reinforcement advantageously distributes the force over a larger area, thereby further improving the pressure resistance.
[0017] The back side is generally the outwardly facing side of the wall here. That is to say, the back side faces the outside of the metal capsule opposite to the volume space surrounded by the capsule.
[0018] According to one embodiment, a set of elongated metal reinforcements attached to the first metal wall may be substantially parallel to the elongated metal reinforcements attached to the second metal wall.
[0019] According to one embodiment, the metal capsule may include a third metal wall connected to both the first metal wall and the second metal wall, the third metal wall including corrugations and a group of elongated metal elements, each of which is attached to at least (two) corrugations. In this way, the third metal wall (which may be the top wall) is also suitable for withstanding the higher pressure inside the metal capsule, thereby improving the overall pressure resistance of the metal capsule.
[0020] According to one embodiment, the elongated metal reinforcement on the second metal wall may include a cutout corresponding to the corrugated shape of the second metal wall. Therefore, the contact interface between the metal reinforcement and the second metal wall follows the shape of the corrugation, thereby improving the connection strength between the metal reinforcement and the second metal wall.
[0021] According to one embodiment, the elongated metal element may be a metal rod.
[0022] According to one embodiment, the rod may comprise a longitudinal cutout at its end portion, wherein the elongated metal reinforcement may be fitted and attached in the cutout. In this way, the connection strength between the rod and the reinforcement is improved. The metal reinforcement may be welded to the rod in the cutout. The longitudinal cutout is a cutout along the longitudinal axis of the rod.
[0023] Alternatively, the metal reinforcement may include a cutout in which the rod fits and is attached.
[0024] According to one embodiment, the wall of the metal enclosure may be made of steel. Steel is a strong material that improves the ability of the metal enclosure to withstand internal pressure.
[0025] In a second aspect of the present invention, there is provided a gas insulated switchgear, comprising: a group of electrical switches; and a metal enclosure according to any one of the embodiments disclosed herein.
[0026] Other effects and features of the second aspect of the present invention are very similar to the effects and features described above in conjunction with the first aspect of the present invention.
[0027] Further features and advantages of the present invention will become apparent when studying the appended claims and the following description. Those skilled in the art realize that different features of the present invention can be combined to create embodiments other than those described in the following, without departing from the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] These and other aspects of the present invention will now be described in more detail with reference to the accompanying drawings showing exemplary embodiments of the present invention, in which:
[0029] Figure 1 is a perspective view of the front side of a metal capsule according to an embodiment of the present invention;
[0030] Figure 2 is a perspective view of a rear side of a metal capsule according to an embodiment of the present invention;
[0031] Figure 3 is an exploded view of a metal capsule according to an embodiment of the present invention;
[0032] Figure 4 is a cross-sectional view of a metal capsule according to an embodiment of the present invention; and
[0033] Figure 5 is a cross-sectional view of a metal capsule according to an embodiment of the present invention. DETAILED DESCRIPTION
[0034] In the detailed description herein, various embodiments of the present invention are described herein with reference to specific embodiments. When describing the embodiments, specific terms are used for clarity. However, the present invention is not limited to the selected specific terms. Although specific exemplary embodiments are discussed, it should be understood that this is for illustrative purposes only. Those skilled in the relevant art will recognize that other components and configurations may be used without departing from the scope of the present invention.
[0035] Figure 1 A front view of a metal enclosure 100 for an electrical switching apparatus is shown. Figure 2 A rear view of the metal capsule 100 is shown. The metal capsule 100 is configured to be pressurized above atmospheric pressure.
[0036] The metal enclosure 100 includes metal walls 102 , 104 , 106 , 108 , 110 that seal a volume for housing an electrical switching apparatus.
[0037] The metal wall includes a first metal wall 102, which is arranged opposite to a second metal wall 110. Figure 2 As more clearly shown, the second metal wall 110 is a corrugated metal sheet having corrugations 112a - d extending along a first axis 114 .
[0038] The metal sheet 110 comprises a set of parallel corrugations 112a - d formed as ridges, all extending parallel to the same longitudinal first axis 114 .
[0039] Furthermore, the third wall 108 provided as a metal plate on the top side of the metal enclosure 100 is connected to both the first metal wall 102 and the second metal wall 110 by welding, etc. The third metal wall 108 includes corrugations 112 parallel to the corrugations 112a-d of the second metal wall 110.
[0040] The side walls 106 and 104 are attached to the first metal wall 102, the second metal wall 110 and the third metal wall 108 by sealed connections. The metal walls 102, 104, 106, 108, 110 may be metal plates. In one embodiment, the walls 102, 104, 106, 108, 110 of the metal enclosure 100 are made of steel.
[0041] A set of elongated metal elements 116a-d are attached to the first metal wall 102 and the second metal wall 110. The elongated metal elements 116a-d are disposed through holes 120, 122 in the first metal wall 102 and the second metal wall 110, respectively. The elongated metal elements 116a-d extend outside the metal enclosure 100.
[0042] Furthermore, a set of elongated metal reinforcements 124 are attached to the back side 126 of the second metal wall 110 outside the metal enclosure 100. Each metal reinforcement 124 is attached to at least two corrugations 112 of the second metal wall 110. Furthermore, each metal reinforcement 124 is attached to at least one of the elongated metal elements 116a-d.
[0043] The corrugations 112a-d extend from the side wall 106 to the side wall 104, but are covered by the metal reinforcement 124. Preferably, the metal reinforcement 124 may have cutouts to allow the corrugations to be arranged under the metal reinforcement. Alternatively, the metal reinforcement may cut through the corrugations.
[0044] In this embodiment, a set of elongated metal reinforcements 128 are each attached to at least two corrugations of the top plate 108. Additionally, elongated metal reinforcements 130 may be attached to an outer side 132 of the first metal wall 102. The set of elongated metal reinforcements 130 attached to the first metal wall 102 are substantially parallel to the elongated metal reinforcements 124 attached to the second metal wall 110.
[0045] The metal reinforcements 124, 128, 130 may be elongated metal plates that are attached to all the corrugations of the respective walls 102, 108, 110. For example, the metal reinforcement 124 extends across and interrupts all the corrugations 112a-d of the second metal wall 110.
[0046] The major axis 134 of the elongated metal reinforcement 124 is angled relative to the axis 114 of the corrugations such that the axes 134 and 114 are not parallel. Preferably, the angle is about 90°. That is, the metal reinforcement 124 is transverse to the corrugations 112a-d.
[0047] Figure 3 is an exploded view of the metal enclosure 100. The elongated metal elements 116a-d extend all the way between the first metal wall 102 and the second metal wall 110. In addition, the corrugations (of which 112a is most evident) extend between the side walls 104 and 106 from one side to the other.
[0048] The metal enclosure 100 may be contained in a gas insulated switchgear 10, which includes a set of electrical switches 11 suitable for operating at 10-52 kV, preferably 12 / 24 / 36, 40.5 kV, and may have a modular structure regarding a combination of switches, which may be assembled in sequence in the metal gas enclosure 100. The switches may be, for example, CC, CCV, CCF, CCCC, etc., wherein C: cable switch module, De: direct cable connection with earthing module, D: direct cable connection module, F: switch-fuse disconnector module, V: vacuum circuit breaker module.
[0049] By inserting rods 116a-d with reinforcement members 130, 124 and utilizing the space between the switches / circuit breakers, the strength of the front first metal wall 102 and the rear second metal wall 110 can be achieved. The strength enhancement is consistent with the number of switches / circuit breakers combined, and the strengthening characteristics will be maintained regardless of the number of switches / circuit breakers. To further improve the strengthening performance, the top 108, the bottom plate 111 and the back plate 110 are all corrugated.
[0050] Figure 4 and Figure 5 1 and 2 are cross-sectional views of the metal package 100 viewed from two different viewing angles. Figure 4 The perspective in is the perspective seen from the front wall, the first metal wall 102 side, and Figure 5 The viewing angle in FIG. 1 is the viewing angle viewed from the rear wall 110 and the second metal wall 110 side.
[0051] First reference Figure 4, the elongated metal elements 116a-d arranged as rods are attached to the back side 132 of the first metal wall 102. To this end, the rods 116a-d are fed through the through holes 120 in the first metal wall 102 and welded to the first metal wall 102. In addition, the metal reinforcement 130 is also welded to the first metal wall along the contact interface between the metal reinforcement and the back side 132 of the first metal wall 102.
[0052] To improve the connection between the rods 116a-d and the reinforcements 130, these rods 116a-d include longitudinal cutouts 142 at their end portions 144, which extend out of the metal enclosure 100 away from the back face 132 of the first metal wall 102. The cutouts 142 are along respective longitudinal axes 146 of the rods 116a-d. The metal reinforcements 130 are arranged in the cutouts 142, where they are welded to be fixed to the respective rods 116a-d.
[0053] In this embodiment, the rods 116b, 116d are welded to one metal reinforcement 130 on the first metal wall 102. The metal reinforcement 130 fits in the cutout 142 at the end 144 of the rods 116b, 116d. The other rods 116a, 116c are welded to another metal reinforcement 130 that fits in the cutout 142 of the rods 116a, 116c.
[0054] Welding is performed along the cutout 142 on both sides of the cutout 142 (eg, both halves of the rod) along the intersection of the metal reinforcement 130 and the rods 116a - d .
[0055] Now turn to Figure 5 , Figure 5 is a perspective view from the second metal wall 110. The rods 116a-d are attached to the back side 126 of the second metal wall 110.
[0056] The end portions 148 of the rods 116a-d are fed through the through holes 122 in the second metal wall 110 and welded thereto. The end portions 148 are located on the opposite ends of the rods 116a-d relative to the end portions 144 attached to the first metal wall 102.
[0057] In addition, the metal reinforcement 124 is welded to the second metal wall 110 along the contact interface between the metal reinforcement 124 and the back surface 126 of the second metal wall 110. The metal reinforcement 124 includes a cutout 152 to accommodate the corrugations 112a-c. Preferably, the shape of the cutout 152 corresponds to the shape of the corrugations 112a-d of the second metal wall 110. The second metal wall 110 and its corrugations 112a-d can be made integrally.
[0058] To improve the connection between the rods 116a-d and the reinforcement 124, the rods 116a-d comprise longitudinal cutouts 154 at their end portions 148. The end portions 148 extend away from the back face 126 of the second metal wall 110 outside the metal enclosure 100.
[0059] The cutouts 154 are along the respective longitudinal axes 146 of the rods 116a-d in the same manner as the cutouts 154 on the opposite ends 144. The metal reinforcements 124 are disposed in the cutouts 154 where they are secured by welding to the respective rods 116a-d.
[0060] The rods 116b, 116d are welded to one metal reinforcement 124 on the second metal wall 110. The metal reinforcement 124 fits in a cutout 154 at the end 154 of the rods 116b, 116d. The other two rods 116a, 116c are welded to another metal reinforcement 124 fitted in the cutout 154 of the rods 116a, 116c.
[0061] Welding is performed along the cut 154 on both sides of the cut 154 (eg, the two halves of the rod) along the intersection of the metal reinforcement 124 and the rods 116a-d. The cut may be formed in the center of the rod such that the cut divides the end portions 144, 148 into two halves.
[0062] Alternatively, the metal reinforcement may include a cutout in which the rod fits and is attached.
[0063] Although four rods 116a-d are shown, the number of rods depends on the specific embodiment used and may be more or less than four. Similarly, the number of corrugations, which is four here, is shown as an example and may vary depending on the embodiment.
[0064] Even though the invention has been described above with reference to specific exemplifying embodiments, many different alterations, modifications and the like will become apparent for those skilled in the art.
[0065] Furthermore, variations of the disclosed embodiments may be understood and implemented by those skilled in the art in practicing the claimed invention by studying the drawings, the disclosure and the appended claims. 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. The fact that certain measures are stated in mutually different dependent claims does not indicate that a combination of these measures cannot be fully utilized.
Claims
1. A metal enclosure (100) for an electrical switching device, the metal enclosure being configured to be pressurized to a pressure above atmospheric pressure, the metal enclosure comprising: A metal wall (102, 104, 106, 108, 110, 111) for sealing a volume space for accommodating the electrical switching device (11), the metal wall comprising a first metal wall (102) arranged opposite to a second metal wall (110), wherein at least the second metal wall is a corrugated metal sheet having corrugations (112a-d) extending along a first axis (114), a set of elongated metal elements (116a-d) attached to the first metal wall and the second metal wall, the elongated metal elements being arranged through holes (120, 122) in the first metal wall and the second metal wall and extending to the exterior of the metal enclosure, A set of elongated metal reinforcements (124) are attached to the back side (126) of the second metal wall outside the metal enclosure, each of the metal reinforcements being attached to at least two corrugations of the second metal wall, wherein each metal reinforcement is attached to at least one of the elongated metal elements.
2. The metal capsule according to claim 1, wherein: Each metal reinforcement is attached to all the corrugations of the second metal wall.
3. The metal capsule according to any one of claims 1 and 2, wherein: The metal reinforcement is an elongated plate arranged along an axis (134) at an angle to the axis of the corrugations.
4. The metal capsule according to claim 3, wherein: The angle is approximately 90°.
5. A metal capsule according to any one of the preceding claims, wherein: The elongated metal element is attached to the back surface of the second metal wall and to the back surface (132) of the first metal wall.
6. A metal capsule according to any one of the preceding claims, wherein: The elongated metal element is attached to the first metal wall and the second metal wall by welding.
7. A metal capsule according to any one of the preceding claims, wherein: The metal reinforcement is attached to the second metal wall by welding.
8. The metal enclosure according to any of the preceding claims, comprising a set of elongated metal reinforcements attached to the back side of the first metal wall outside the metal enclosure, each of the metal reinforcements being attached to at least one of the elongated metal elements.
9. The metal capsule according to claim 8, wherein: The set of elongated metal reinforcements attached to the first metal wall are substantially parallel to the elongated metal reinforcements attached to the second metal wall.
10. The metal capsule according to any one of the preceding claims, comprising a third metal wall (108) connected to both the first metal wall and the second metal wall, the third metal wall comprising corrugations (112) and a set of elongated metal reinforcements (128), each of the elongated metal reinforcements being attached to at least two corrugations.
11. A metal capsule according to any one of the preceding claims, wherein: The elongated metal reinforcement on the second metal wall includes cutouts (152) having a shape corresponding to the corrugations of the second metal wall.
12. A metal capsule according to any one of the preceding claims, wherein: The elongated metal element is a metal rod.
13. The metal capsule according to claim 12, wherein: The rod comprises a longitudinal cutout (142, 154) at an end portion (144, 148) thereof, wherein the elongated metal reinforcement is fitted and attached in the cutout, or wherein the metal reinforcement comprises a cutout, wherein the rod is fitted and attached in the cutout.
14. A metal capsule according to any one of the preceding claims, wherein: The walls of the metal enclosure are made of steel.
15. A gas insulated switchgear (10), comprising: a set of electrical switches (11); A metal capsule according to any preceding claim pressurised by a gas.