Switching device

Abstract

The invention relates to a switching device (10) comprising: a first part (20); a second portion (30); and a thermal bridge (40); wherein the first portion is configured to be held at a high voltage; wherein the second portion is configured to be maintained at a ground potential; wherein the thermal bridge is thermally connected with the first part; wherein the thermal bridge is thermally connected with the second part; wherein, when the first portion is maintained at a high voltage and the second portion is maintained at a ground potential, the thermal bridge is configured to electrically insulate the second portion from the first portion; and wherein, when the first portion is held at a high voltage and the second portion is held at ground potential, the thermal bridge is configured to transfer heat from the first portion to the second portion.

Description

Technical Field

[0001] The invention relates to a thermal bridge for a switchgear, such as an air-insulated switchgear or a gas-insulated switchgear for medium voltage applications, and a switchgear having such a thermal bridge. Background Art

[0002] Electrical switching devices conduct current and therefore generate resistive losses, which cause a temperature rise. Standards specify the permissible temperature rise limits.

[0003] In many applications, it is desirable to conduct this heat away from where it is generated to other parts of the switchgear where the temperature is lower. Thus, it is possible to avoid exceeding temperature limits or to increase the current that can be carried with an allowable temperature rise. The transfer of heat away from its origin (e.g. a conductor) is achieved by thermal conduction, radiation and convection. To secure the conductor, an insulator or insulating sleeve, for example made of epoxy resin, is often used. However, insulating materials like widely used epoxy resins have low thermal conductivity and are therefore inefficient in conducting the heat away from its origin.

[0004] In electrical switchgear, a connection must be established between high voltage components and grounded components (e.g. the frame of the switchgear), and this has to be done using electrical isolators. However, the heat transfer of these isolator materials is very small. Therefore, currently other means must be provided to cool such high voltage components of the switchgear, which increases cost and complexity.

[0005] It is necessary to solve this problem. Summary of the invention

[0006] Therefore, it would be advantageous to improve the ability to extract thermal energy from high temperature and high pressure components of switchgear.

[0007] The objects of the invention are solved by the subject-matter of the independent claims, wherein further embodiments are incorporated in the dependent claims.

[0008] In a first aspect, a thermal bridge for a switchgear is provided, the switchgear comprising a first portion and a second portion. The first portion is configured to be maintained at a high voltage, and the second portion is configured to be maintained at a ground potential. The thermal bridge is configured to be located between the first portion and the second portion and to be thermally connected to the first portion and to be thermally connected to the second portion. When the first portion is maintained at a high voltage and the second portion is maintained at a ground potential, the thermal bridge is configured to electrically insulate the second portion from the first portion. When the first portion is maintained at a high voltage and the second portion is maintained at a ground potential, the thermal bridge is configured to transfer heat from the first portion to the second portion.

[0009] In one example, the thermal bridge comprises a plastic material.

[0010] In one example, the thermal conductivity of the thermal bridge is about 8 W / mK.

[0011] In one example, the thermal bridge includes 1800-9333 / WT.

[0012] In one example, the thermal bridge comprises a ceramic material.

[0013] In one example, the thermal conductivity of the thermal bridge is about 90 W / mK.

[0014] In one example, the thermal conductivity of the thermal bridge is about 92 W / mK.

[0015] In one example, the insulation (dielectric strength) of the thermal bridge is about 63 KV / mm.

[0016] In one example, the thermal bridge includes ANB-90 from JUCI Technologies, Inc.

[0017] In one example, the thermal bridge comprises Shapal Hi Msoft from Tokuyama Corporation.

[0018] In one example, the second portion includes a frame of the switchgear, a heat sink, a cooler, a heat pipe, or a thermosyphon.

[0019] In one example, the connection between the first portion and the thermal bridge includes a welded connection, a soldered connection, a temperature-pressed connection, a screw-pressed connection, or a press-fit connection.

[0020] In one example, the connection between the second portion and the thermal bridge includes a welding connection, a brazing connection (soldering connection), a temperature-pressing connection, a screw-pressing connection, or a pressing connection.

[0021] In a second aspect, there is provided a switchgear comprising:

[0022] - Part I;

[0023] - Part II; and

[0024] - Thermal bridges.

[0025] The first portion is configured to be maintained at a high voltage. The second portion is configured to be maintained at a ground potential. The thermal bridge is thermally connected to the first portion. The thermal bridge is thermally connected to the second portion. When the first portion is maintained at a high voltage and the second portion is maintained at a ground potential, the thermal bridge is configured to electrically insulate the second portion from the first portion. When the first portion is maintained at a high voltage and the second portion is maintained at a ground potential, the thermal bridge is configured to transfer heat from the first portion to the second portion.

[0026] In one example, the thermal bridge comprises a plastic material.

[0027] In one example, the thermal conductivity of the thermal bridge is about 8 W / mK.

[0028] In one example, the thermal bridge includes 1800-9333 / WT.

[0029] In one example, the thermal bridge comprises a ceramic material.

[0030] In one example, the thermal conductivity of the thermal bridge is about 90 W / mK.

[0031] In one example, the thermal conductivity of the thermal bridge is about 92 W / mK.

[0032] In one example, the insulation (dielectric strength) of the thermal bridge is about 63 KV / mm.

[0033] In one example, the thermal bridge includes ANB-90 from JUCI Technologies, Inc.

[0034] In one example, the thermal bridge comprises Shapal Hi Msoft from Tokuyama Corporation.

[0035] In one example, the second portion includes a frame of the switchgear, a heat sink, a cooler, a heat pipe, or a thermosyphon.

[0036] In one example, the thermal bridge is configured such that the connection between the first portion and the thermal bridge comprises a welded connection, a brazed connection (soldering connection), a temperature-pressed connection, a screw-pressed connection, a crimped connection.

[0037] In one example, the thermal bridge is configured such that the connection between the second portion and the thermal bridge comprises a welded connection, a brazed connection (soldering connection), a temperature-pressed connection, a screw-pressed connection, a press-fit connection.

[0038] The above aspects and examples will become apparent and elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Exemplary embodiments will be described below with reference to the following drawings:

[0040] Figure 1 A schematic diagram of a high voltage portion of a switchgear and a grounded portion of a switchgear with a thermal bridge therebetween electrically isolating the first portion from the second portion while enabling heat to flow from the first portion to the second portion is shown. DETAILED DESCRIPTION

[0041] Figure 1The invention relates to a thermal bridge for a switchgear, for example an air-insulated switchgear or a gas-insulated switchgear for medium voltage applications, and a switchgear having such a thermal bridge.

[0042] In one example, the switchgear 10 includes a first portion 20 and a second portion 30. The first portion is configured to be maintained at a high voltage, while the second portion is configured to be maintained at ground potential. A thermal bridge 40 may then be used in the switchgear to secure the first portion to the second portion, thereby maintaining electrical isolation between the portions while helping to cool the first portion by enabling heat to flow from the hot first portion to the cooler second portion, where, for example, the first portion may be heated due to Joule heating. The thermal bridge is configured to be located between the first portion and the second portion, and to be thermally connected to the first portion and to be thermally connected to the second portion. When the first portion is maintained at a high voltage and the second portion is maintained at ground potential, the thermal bridge is configured to electrically insulate the second portion from the first portion. When the first portion is maintained at a high voltage and the second portion is maintained at ground potential, the thermal bridge is configured to transfer heat from the first portion to the second portion.

[0043] In one example, the thermal bridge comprises a plastic material.

[0044] In one example, the thermal conductivity of the thermal bridge is about 8 W / mK.

[0045] In one example, the thermal bridge includes 1800-9333 / WT.

[0046] In one example, the thermal bridge comprises a ceramic material.

[0047] In one example, the thermal conductivity of the thermal bridge is about 90 W / mK.

[0048] In one example, the thermal conductivity of the thermal bridge is about 92 W / mK.

[0049] Materials with different thermal conductivities can be tried and tested.

[0050] In one example, the insulation (dielectric strength) of the thermal bridge is about 63 KV / mm.

[0051] Materials with different insulating properties can be tried and tested.

[0052] In one example, the thermal bridge includes ANB-90 from JUCI Technologies, Inc.

[0053] In one example, the thermal bridge comprises Shapal Hi Msoft from Tokuyama Corporation.

[0054] In one example, the second portion includes a frame of the switchgear, a heat sink, a cooler, a heat pipe, or a thermosyphon.

[0055] In one example, the connection 50 between the first portion and the thermal bridge comprises a welded connection, a brazed / soldered connection, a temperature-pressed connection, a screw-pressed connection, or a press-fit connection.

[0056] In one example, the connection 60 between the second portion and the thermal bridge comprises a welded connection, a brazed connection / soldered connection, a temperature-pressed connection, a screw-pressed connection, or a press-fit connection.

[0057] For example, a switchgear having a thermal bridge may be constructed. Thus, such a switchgear comprises a first part, a second part and a thermal bridge. The first part is configured to be maintained at a high voltage. The second part is configured to be maintained at ground potential. The thermal bridge is thermally connected to the first part. The thermal bridge is thermally connected to the second part. When the first part is maintained at a high voltage and the second part is maintained at ground potential, the thermal bridge is configured to electrically insulate the second part from the first part. When the first part is maintained at a high voltage and the second part is maintained at ground potential, the thermal bridge is configured to transfer heat from the first part to the second part. Thus, again, the thermal bridge is used to help fix the first part relative to the second part, thereby providing electrical isolation of the high voltage, but at the same time helps provide cooling of the first part by heat conduction from the first part to the second part via the thermal bridge.

[0058] In one example, the thermal bridge comprises a plastic material.

[0059] In one example, the thermal conductivity of the thermal bridge is about 8 W / mK.

[0060] In one example, the thermal bridge includes 1800-9333 / WT.

[0061] In one example, the thermal bridge comprises a ceramic material.

[0062] In one example, the thermal conductivity of the thermal bridge is about 90 W / mK.

[0063] In one example, the insulation (dielectric strength) of the thermal bridge is about 63 KV / mm.

[0064] In one example, the thermal bridge includes ANB-90 from JUCI Technologies, Inc.

[0065] In one example, the second portion includes a frame of the switchgear, a heat sink, a cooler, a heat pipe, or a thermosyphon.

[0066] In one example, the thermal bridge is configured such that the connection between the first portion and the thermal bridge comprises a welded connection, a brazed / soldered connection, a temperature-pressed connection, a screwed connection, a crimped connection.

[0067] In one example, the thermal bridge is configured such that the connection between the second portion and the thermal bridge comprises a welded connection, a brazed / soldered connection, a temperature-pressed connection, a screwed connection, a crimped connection.

[0068] Therefore, the inventors realized that instead of fixing the high voltage component to the grounded component of the switchgear via an electrical insulator which is also a thermal insulator, it is better to use a new material which is both an electrical insulator and a thermal conductor to ground the high voltage component, thereby helping to promote cooling of the high voltage component because the heat can now flow to the grounded component.

[0069] The grounded component may be the frame of the switchgear, thereby allowing heat to be transferred to the external environment by convection, conduction and radiation.

[0070] Additionally, the thermal bridge can be used to connect to a grounded heat sink or cooler, or a grounded heat pipe or grounded thermosyphon, which can further increase cooling efficiency. Since the thermal link provides electrical isolation but provides heat flow, the design of the heat pipe or thermosyphon can be simpler because all parts of the heat pipe or thermosyphon can be at ground potential and no internal insulating parts are required within the heat pipe or thermosyphon.

[0071] Reference Numbers

[0072] 10Switchgear

[0073] 20 A first portion of the switching device that is at a high voltage and temperature, for example due to Joule heating caused by current flowing through the first portion

[0074] 30 A second part of the switching device which is at ground potential.

[0075] 40 Thermal bridge between the first and second parts of the switchgear.

[0076] 50 Connection between the first part of the switchgear and the thermal bridge.

[0077] 60 A connection between the second part of the switchgear and the thermal bridge.

[0078] Although the present invention has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description should be regarded as illustrative or exemplary rather than restrictive. The present invention is not limited to the disclosed embodiments. Other 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 dependent claims.

Claims

1. A switch device (10), comprising: - first part (20); - the second part (30); and - thermal bridge (40); wherein the first portion is configured to be maintained at a high voltage; wherein the second portion is configured to be maintained at ground potential; wherein the thermal bridge is thermally connected to the first portion; wherein the thermal bridge is thermally connected to the second portion; wherein, when the first portion is maintained at a high voltage and the second portion is maintained at a ground potential, the thermal bridge is configured to electrically insulate the second portion from the first portion; and Wherein, when the first part is maintained at a high voltage and the second part is maintained at a ground potential, the thermal bridge is configured to transfer heat from the first part to the second part.

2. The switchgear according to claim 1, wherein: The thermal bridge comprises a plastic material.

3. The switchgear according to any one of claims 1 to 2, wherein: The thermal conductivity of the thermal bridge is approximately 8 W / mK.

4. The switchgear according to any one of claims 1 to 3, wherein: The thermal bridge comprises 1800-9333 / WT.

5. The switchgear according to claim 1, wherein: The thermal bridge comprises a ceramic material.

6. The switchgear according to any one of claims 1 or 5, wherein: The thermal bridge has a thermal conductivity of approximately 90-92 W / mK.

7. The switchgear according to any one of claims 1 or 5-6, wherein: The insulation of the thermal bridge is about 63 KV / mm.

8. The switchgear according to any one of claims 1 or 5-7, wherein: The thermal bridge comprises ANB-90 from JUCI Technology Co., Ltd.; or wherein the thermal bridge comprises Shapal Hi Msoft from Tokuyama Corporation.

9. The switchgear according to any one of claims 1 to 8, wherein: The second part comprises a frame of the switchgear, a heat sink, a cooler, a heat pipe or a thermosyphon.

10. The switchgear according to any one of claims 1 to 9, wherein: The connection (50) between the first part and the thermal bridge comprises a welding connection, a soldering connection, a temperature-pressing connection, a screw-pressing connection, or a press-fit connection.

11. The switchgear according to any one of claims 1 to 10, wherein: The connection (60) between the second part and the thermal bridge comprises a welding connection, a soldering connection, a temperature-pressing connection, a screw-pressing connection, or a pressing connection.

12. A thermal bridge (40) for a switchgear (10), the switchgear comprising a first part (20) and a second part (30), wherein: The first portion is configured to be held at a high voltage, and the second portion is configured to be held at a ground potential; and wherein the thermal bridge is configured to be located between the first portion and the second portion and to be thermally connected to the first portion and to be thermally connected to the second portion; wherein, when the first portion is maintained at a high voltage and the second portion is maintained at a ground potential, the thermal bridge is configured to electrically insulate the second portion from the first portion; and Wherein, when the first part is maintained at a high voltage and the second part is maintained at a ground potential, the thermal bridge is configured to transfer heat from the first part to the second part.

13. The thermal bridge according to claim 12, wherein: The thermal bridge comprises a plastic material.

14. The thermal bridge according to claim 12, wherein: The thermal bridge comprises a ceramic material.

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