switchgear

Abstract

Embodiments of the present disclosure relate to switchgear. A gas-insulated, air-blown switchgear is provided for operation within a sealed, airtight enclosure of power distribution switchgear. The sealed, airtight enclosure is filled with a dielectric gas having a lower global warming potential than SF6. The switchgear offers at least one of the advantages of improved compactness, minimized electrical stress, maximized heat dissipation, and reduced environmental impact.

Description

Technical Field

[0001] Aspects of the present invention relate to switchgear and power distribution switchgear including the switchgear. Background Art

[0002] Switchgear is used in power systems to control, protect, and isolate electrical equipment. Challenges with such switchgear include minimizing electrical stress on the electrical insulation and arc-extinguishing dielectric, maximizing heat dissipation, and reducing the switchgear's environmental impact—especially optimizing all of these aspects simultaneously.

[0003] Current medium-voltage switchgear is typically gas-insulated, where the insulating gas may be sulfur hexafluoride (SF6). Using SF6 allows for compact switchgear designs because of its excellent arc extinguishing, electrical insulation, and heat dissipation properties. Despite its many advantages, SF6's high global warming potential (GWP) has led to the introduction of alternatives.

[0004] WO2014154292A1 discloses an SF6-free switch assembly and switchgear in which a vacuum circuit breaker is mounted on a single conductive housing. US8232496B2 and US7767917B2 disclose air-blowing load-disconnect switches. In the disconnected position, separate field controllers electrically shield the moving and fixed contact sets. These switches have a thermoplastic housing for the actuator mechanism, and SF6 is primarily used as the dielectric insulation medium.

[0005] EP3252793A1 discloses a switch device having a first conductive housing and a second conductive housing, wherein the first conductive housing surrounds an actuator mechanism for a first contact assembly and the second conductive housing surrounds a second contact assembly. The first conductive housing is arranged at a distance from the second conductive housing. Summary of the Invention

[0006] In view of this, a switchgear according to claim 1 and a power distribution switchgear according to claim 14 are provided.

[0007] According to one aspect, a gas-insulated, gas-blown switchgear is provided for operation within a sealed, airtight enclosure of a power distribution switchgear device, the sealed, airtight enclosure being filled with a dielectric gas having a global warming potential lower than that of SF6. The switchgear includes a fixed contact assembly 210 and a movable contact assembly 110. The movable contact assembly 110 is longitudinally movable along an axis 112 of the movable contact assembly between a closed state and an open state of the switchgear. The movable contact assembly 110 is electrically connected to the fixed contact assembly 210 in the closed state of the switchgear and is not electrically connected to the fixed contact assembly 210 in the open state of the switchgear. The switchgear also includes a switch actuator mechanism 120 for transmitting rotational movement of an actuating shaft to longitudinal movement of the movable contact assembly 110. The switch device also includes a grounding switch and a first terminal 160 electrically connected to the movable contact assembly 110 via a first conductive wire 140. The first conductive wire 140 includes a flexible conductor 142 for accommodating longitudinal movement of the movable contact assembly 110. The first terminal 160 is further electrically connected to the grounding switch via a second conductive wire 460. The switch device also includes a second terminal electrically connected to the fixed contact assembly 210 and a conductive first housing 100 surrounding at least a portion of the movable contact assembly 110, thereby electrically shielding the movable contact assembly 110 when the switch device is in the open state. The first housing 100 also surrounds the switch actuator mechanism 120, the first conductive wire 140, and at least a portion of the grounding switch. The first housing 100 includes a ventilation opening for allowing convection of a dielectric gas from outside the first housing 100 through the first housing 100. At least a portion of at least one of the first terminal 160, the first conductive wire 140, and the second conductive wire 460 is thermally conductively connected to the first housing 100. The reference numerals given herein are for illustration only and are not intended to limit the present invention to Figure 1 The embodiment shown in

[0008] According to another aspect, a power distribution switchgear is provided, the power distribution switchgear including a sealed gastight enclosure and a switchgear for operating with a dielectric gas having a global warming potential lower than SF6 within the sealed gastight enclosure.

[0009] Some advantages are as follows: The switchgear and switchgear comprising the switchgear have at least some of the advantages of improved compactness, minimization of electrical stresses, maximization of heat dissipation and reduced environmental impact, and preferably several or even all of these advantages simultaneously.

[0010] Using dielectric gases with lower global warming potential than SF6 (such as air or gas mixtures) can reduce environmental impact, but they provide lower electrical insulation efficiency than SF6, resulting in less compact designs for the same dielectric withstand capability. Special housing designs, such as rounded / smooth outer surfaces (to provide good electric field control), can minimize electrical stress. However, housings optimized for electric field control (e.g., rounded / smooth outer surfaces) are not optimized for heat dissipation, necessitating additional heat dissipation measures or a reduction in rated current. Consequently, it is difficult to simultaneously address the challenges of compactness, environmental impact, electrical stress, and heat dissipation.

[0011] The switching device and the switching apparatus comprising the switching device have at least one of the following advantages: reduced impact on the environment (e.g., operation with a dielectric gas having a global warming potential lower than SF6), minimization of electrical stresses (e.g., the switch actuator mechanism / movable contact assembly is enclosed in a conductive housing having a circular outer surface), and preferably simultaneous maximization of heat dissipation (e.g., because at least a portion of at least one of the first terminal 160, the first conductive wire, and the second conductive wire 460 is thermally conductively connected to the (first) housing).

[0012] Further advantages, features, aspects and details, which can be combined with the embodiments described herein, are apparent from the dependent claims, the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The details will be described below with reference to the accompanying drawings, in which Figure 1 A schematic diagram of a switch arrangement according to embodiments described herein is shown. DETAILED DESCRIPTION

[0014] Reference will now be made in detail to various embodiments, one or more examples of which are shown in each figure. Each example is provided by way of explanation and is not meant to be limiting. For example, features illustrated or described as part of an embodiment may be used in any other embodiment or in conjunction with any other embodiment to produce further embodiments. This disclosure is intended to encompass such modifications and variations.

[0015] In the following descriptions of the drawings, the same reference numerals refer to the same or similar components. Generally, only the differences with respect to the various embodiments are described. Unless otherwise specified, the description of a part or aspect in one embodiment also applies to the corresponding part or aspect in another embodiment.

[0016] The reference numbers used in the figures are for illustration only. The aspects described herein are not limited to any particular embodiment. Instead, any aspect described herein may be combined with any other aspect(s) or embodiment(s) described herein, unless otherwise specified.

[0017] According to aspects or embodiments described herein, the switchgear is optimized for at least one of compactness, environmental impact, electrical stress, and heat dissipation.

[0018] Figure 1 A schematic diagram of a switchgear according to embodiments described herein is shown. The switchgear can be gas-insulated. The switchgear can be a gas-blown type switchgear. The switchgear can be configured to operate within a sealed, airtight enclosure. The switchgear can be used in power distribution switchgear. The sealed, airtight enclosure can be filled with a dielectric gas. The global warming potential of the dielectric gas can be lower than that of SF6.

[0019] The switch device may include a fixed contact assembly 210. The switch device may include a movable contact assembly 110. The movable contact assembly 110 may be movable longitudinally along an axis 112 of the movable contact assembly.

[0020] The movable contact assembly 110 may be movable between a closed state and an open state of the switch device. In the closed state (of the switch device), the movable contact assembly 110 may be electrically connected to the fixed contact assembly 210. In the open state (of the switch device), the movable contact assembly 110 cannot be electrically connected to the fixed contact assembly 210.

[0021] The switch device may comprise a switch actuator mechanism 120. The switch actuator mechanism 120 may be adapted to transfer a rotational movement of the actuation shaft to a longitudinal movement of the movable contact element 110.

[0022] The switch device may include a grounding switch. At least a portion of the grounding switch may be housed in the first housing 100. The grounding switch may be electrically connected to the first housing 100. For example, when the grounding switch is in a closed state, the grounding switch may be used to ground the first housing 100.

[0023] The grounding switch may be a knife switch. The grounding switch may include a fixed grounding contact and a movable grounding contact 440. For example, when the grounding switch is in an off state, the movable grounding contact 440 may be accommodated (enclosed / completely enclosed) in the first housing 100.

[0024] The fixed contact assembly 210 may be disposed within a second (conductive) housing 200. The second housing may be electrically / mechanically secured to the busbar(s). The busbar(s) may be a distribution switchgear in which the switchgear is disposed. For example, the second housing 200 may include a mechanical attachment interface for attaching to the busbars. Alternatively, the second housing 200 may be welded or soldered to the busbars.

[0025] In the embodiments described herein, for example, with reference to the first housing 100 and / or the second housing 200, a first object enclosed (enclosed / arranged, etc.) within a second object can be defined as a first object having no portion protruding beyond the outline of the second object enclosing the first object. For example, the movable contact assembly 110 can be enclosed within the first housing 100 (e.g., in an open state), which can be defined as no portion (component) of the movable contact assembly 110 protruding outside the first housing 100. In this example, the first housing 100 forms an effective electric field controller.

[0026] As described in the embodiments herein, the first housing 100 and / or the second housing 200 may function as both an electric field controller and a heat exchanger for the movable contact assembly 110 and / or the fixed contact assembly 210 , respectively.

[0027] The movement of the movable contact assembly 110 is typically accommodated by a full-length flexible conductor. The manufacturing / processing costs of a full-length flexible conductor are typically high. Therefore, the first conductive line 140 may include a non-flexible conductor 144 portion. The flexible conductor 142 portion and the non-flexible conductor 144 portion of the first conductive line 140 may be in accordance with the embodiments described herein.

[0028] The switch device may include a first terminal 160. The first terminal 160 may be a single component. Alternatively, the first terminal may include two parts, a first terminal inner part 160a disposed inside the first housing 100, and a first terminal outer part 160b disposed outside the first housing 100.

[0029] The first terminal 160 (first terminal inner portion 160a) may be electrically connected to the movable contact assembly 110 via the first conductive wire 140. The first conductive wire 140 may include a flexible conductor 142. The flexible conductor 142 may be adapted to accommodate longitudinal movement of the movable contact assembly 110.

[0030] The first terminal 160 (the first terminal inner portion 160a) may be electrically connected to the grounding switch via the second conductive wire 460. For example, the first terminal 160 or the first terminal inner portion 160a may be (electrically) connected to the second conductive wire 460. The second conductive wire 460 may in turn be connected to the grounding switch or a portion of the grounding switch, such as the movable grounding contact 440.

[0031] The first terminal 160 (first terminal outer portion 160b) can be an electrical connector (socket) or an electrical bushing. The first terminal 160 can provide an electrical connection point from the outside of the first housing 100 to the inside of the first housing 100 (to the first conductive wire 140). The first terminal 160 can be a static connector element. The first terminal 160 can be partially arranged inside the first housing (first terminal inner portion 160a) and partially arranged outside the first housing (first terminal outer portion 160b).

[0032] The first terminal 160 (first terminal inner portion 160a) may be connected to the inflexible conductor 144 of the first conductive line 140. The inflexible conductor 144 may in turn be connected to the flexible conductor 142 of the first conductive line 140. The flexible conductor 142 may in turn be connected to the movable contact assembly 110.

[0033] Alternatively, the first terminal (first terminal inner portion 160a) may be directly (electrically) connected to the flexible conductor 142 of the first conductive line 140, for example, at a first end portion of the flexible conductor 142. The second end portion of the flexible conductor 142 may be (electrically) connected to the movable contact assembly 110. Then, the non-flexible conductor 144 may be (electrically) connected to the first terminal (first terminal inner portion 160a), for example, in parallel with the flexible conductor 142.

[0034] In another embodiment, the non-flexible conductor 144 is the primary electrical connection between the first terminal (the first terminal inner portion 160a) and the movable contact assembly 110 via the first housing 100 (e.g., via the first housing 100 and another non-flexible conductor (not shown) between the first housing 100 and the movable contact assembly 110).

[0035] According to embodiments that can be combined with other embodiments described herein, the first terminal may be attached (fixed) to the first housing 100 at the first terminal inner portion 160a, for example between the first terminal outer portion 160b and an end portion of the first terminal inner portion 160a, or between the first terminal outer portion 160b and a position where the first terminal outer portion 160a is (electrically) connected to the first conductive wire 140, the flexible conductor 142, the non-flexible conductor 144 and / or the second conductive wire 460.

[0036] In an embodiment, the connection between the first terminal 160 (e.g., the first terminal inner portion 160a) and the first housing 100 can be thermally and / or electrically conductive. In further embodiments, which can be combined with other embodiments described herein, the first terminal 160 can be connected to the first housing 100 at the first terminal inner portion 160a. Alternatively, the first terminal 160 can be connected to the first housing 100 at a location between the connection with the first conductive wire 140 (or the inflexible conductor 144) and the first terminal outer portion 160b (or the periphery of the first housing 100).

[0037] Furthermore, at least a portion of at least one of the first conductive wire 140 , the second conductive wire 460 and the first terminal 160 (particularly at least a portion of the first terminal inner portion 160 a ) may be (thermally) connected to the first housing 100 .

[0038] Connecting internal conductive components such as first conductive wire 140 , second conductive wire 460 and / or first terminal inner portion 160 a , alone or in combination, (thermally conductively) to first housing 100 may improve heat dissipation, eg, to the exterior of first housing 100 .

[0039] As a result, heat dissipation, electric field control and mechanical stability are improved.

[0040] The first terminal 160 or the first terminal outer portion 160a may be (electrically) connected to the first conductive line 140, the flexible conductor 142, the inflexible conductor 144 and / or the second conductive line 460. Thus, heat dissipation and electric field control are improved.

[0041] The length of the flexible conductor 142 may be only that required to accommodate the movement of the movable contact assembly 110. For example, the flexible conductor 142 may be attached to the first housing 100 at a position that appropriately minimizes the distance between the first housing 100 and the movable contact assembly 110.

[0042] The length of the non-flexible conductor 144 can be sufficient to provide adequate heat conduction. The required heat conduction can correspond to a specific switch device, such as a rated current. For example, the length of the non-flexible conductor 144 can be at least 10%, preferably at least 20%, more preferably at least 30%, and most preferably at least 40% of the length of the flexible conductor 142. Thus, heat dissipation is substantially improved.

[0043] Alternatively, or in addition, the inflexible conductor 144 may be shorter or even very short.

[0044] According to an embodiment, the shapes and sizes of the first conductive wire 140, the non-flexible conductor 144, the first terminal portion 160a, the second conductive wire and / or the conductive portion of the first housing 100 can provide a distance of at least 200 mm from the first housing 100. 2 The contact area is preferably at least 400 mm 2 , more preferably at least 600 mm 2 , or most preferably at least 800 mm 2 .

[0045] In an example, the contact area between the first conductive line 140 (eg, the non-flexible conductor 144) and the first housing 100 may be at least 200 mm. 2 In another example, at least a portion of the first terminal 160 , the first conductive line 140 , and / or the second conductive line 460 may be thermally conductively connected to the first housing 100 .

[0046] Therefore, heat dissipation can be substantially improved without compromising dielectric withstand capability.

[0047] According to an embodiment, the non-flexible conductor 144 may have a surface substantially consistent with the surface of the first housing 100. According to a further embodiment, the non-flexible conductor 144 may be fixed to the first housing 100 using at least one (preferably at least two) fasteners (e.g., M6 bolts). The fasteners fixing the non-flexible conductor 144 to the first housing may each have a tightening force of at least 10 Nm. According to an embodiment, the non-flexible conductor 144 may be in the form of a strip.

[0048] In embodiments that can be combined with other embodiments described herein, the number of fastening / fixing points (eg, bolts) between the first housing 100 and the non-flexible conductor 144 may be increased or may be multiple. Thus, the cooling process or heat dissipation may be improved.

[0049] In embodiments where the fastening / fixing point(s) are in weak (electrical) contact (bonding / touching), unwanted parallel currents may be introduced. Therefore, an (electrically) insulating layer or component may be used, for example, at the joint to (electrically) insulate the first housing 100 from the non-flexible conductor 144, thereby removing the weak (electrical) contact (bonding / touching).

[0050] Because the first housing 100 can be electrically conductive and / or have the same electrical potential as the movable contact assembly 110, the inner surface of the first housing 100 does not contribute to electric field control. Therefore, the inner surface of the first housing 100 can be optimized for heat dissipation. For example, the first housing 100 can be optimized as a heat sink, e.g., the first housing 100 can be a heat sink for at least one component within the first housing 100. Consequently, heat dissipation is improved.

[0051] The first shell 100 may have a peripheral or outer (external) form (shape or surface or profile or geometry or shape) suitable for use as an electric field controller. The periphery of the first shell 100 may be circular. The periphery of the first shell 100 may have a minimum radius of curvature. The minimum radius of curvature may be 1 mm, preferably 4 mm, and even more preferably 8 mm, and most preferably 12 mm. The periphery of the first shell 100 may vary depending on adjacent components, for example depending on (adjacent) components inside and outside the first shell 100. Therefore, electrical stress is substantially minimized. Therefore, dielectric withstand capability / compactness is substantially improved.

[0052] In an embodiment, the periphery of the first housing 100 may include only the conductive portion of the periphery of the first housing 100. For example, the conductive periphery of the first housing 100 may be adapted to function as an electric field controller, for example, being circular and / or having a minimum radius of curvature. In an example, the first housing 100 or a substantial portion thereof (e.g., the first housing 100 excluding the connector connecting the first housing 100 to the sealed, airtight enclosure surrounding the first housing 100) may be made of a metal (e.g., zinc, aluminum, copper, or an alloy thereof). Thus, electrical stress is minimized. Consequently, dielectric withstand capability / compactness is improved.

[0053] At least one component inside the first housing 100 may be a conductive component. The at least one component inside the first housing may include the movable contact assembly 110, the first conductive wire 140, the non-flexible conductor 144, the grounding switch, the movable grounding contact 440, the second conductive wire 460, and / or any portion thereof. Therefore, heat dissipation is improved.

[0054] Components such as the first housing 100, the second housing 200, and / or at least one component inside the first housing 100 (or the second housing 200) may be made of metal (e.g., zinc, aluminum, copper, or alloys thereof). Zinc has a lower production (material) cost, while copper has better electrical and thermal conductivity. Aluminum provides a balance between production (material) cost and electrical and thermal conductivity.

[0055] According to an embodiment, the internal geometry of the first shell 100 can have optimized contact with at least one component, such as a maximum contact area, contact optimized for heat transfer / conduction, and / or the inner surface of the first shell 100 that contacts the surface (contact surface) of at least one component inside the first shell 100 matches / corresponds to the surface (contact surface) of at least one component inside the first shell 100.

[0056] According to an embodiment, the first housing 100 may be optimized for thermal contact conductance (minimum thermal contact resistance) with at least one component inside the first housing 100. For example, the first housing 100 may have a minimum contact pressure, for example, a connector (e.g., two or more bolts (e.g., M6 bolts)) connecting at least one component inside the first housing 100 to the first housing may have a minimum tightening torque (e.g., at least 10 Nm on each bolt), and / or be made of the same material as one of the at least one component inside the first housing 100.

[0057] More generally, any combination of contact pressure, gap material, surface roughness, waviness and flatness, surface deformation, surface cleanliness and thermal conductivity (of the contact surface between at least one component inside the first shell 100 and the inner surface of the first shell 100) can be used to appropriately optimize heat dissipation from at least one component inside the first shell 100 to the outside of the first shell 100.

[0058] The second conductive line 460 may include a non-flexible conductor portion according to the embodiment of the non-flexible conductor 144 of the first conductive line 140. For example, the second conductive line 460 may include a flexible conductor and a non-flexible conductor. The non-flexible conductor of the second conductive line 460 may be formed in the same manner as the non-flexible conductor 144 of the first conductive line 140 to improve heat dissipation. The inner surface of the first housing 100 may be appropriately optimized for heat transfer with the second conductive line 460 and / or the non-flexible conductor of the second conductive line 460.

[0059] One end of the flexible conductor 142 of the first conductive wire 140 may be electrically connected to the movable contact assembly 110, and the other end may be electrically connected to the non-flexible conductor 144 of the first conductive wire 140. Therefore, one end of the non-flexible conductor 144 may be electrically connected to the flexible conductor 142, and the other end may be electrically connected to the first terminal 160 (first terminal inner portion 160a).

[0060] Therefore, the movable contact assembly 110, the first conductive wire 140, the grounding switch, and / or the movable grounding contact 440 can be well thermally connected to the first housing 100, for example, in good thermal conductivity connection with the first housing 100. Therefore, the first housing 100 can be a heat sink for the movable contact assembly 110, the first conductive wire 140, the grounding switch, and / or the movable grounding contact 440.

[0061] In a specific example, the first conductive line 140 may include a solid copper bar as the non-flexible conductor 144, which may be placed on the flat inner surface of the first housing 100 and fixed thereto with bolts. Thus, heat dissipation is improved.

[0062] The switch device may include a second terminal that may be electrically connected to the fixed contact assembly 210 .

[0063] The switch device may include a conductive first housing 100. The first housing 100 may surround at least a portion of a movable contact assembly 110. When the switch device is in an off state, the first housing 100 may electrically shield the movable contact assembly 110. For example, such as when the switch device is in an off state, the first housing 100 may surround the movable contact assembly 110.

[0064] The first housing 100 may enclose the switch actuator mechanism 120. The first housing 100 may enclose the first conductive wire 140. The first housing 100 may enclose a portion of the grounding switch.

[0065] According to an embodiment, the first housing 100 and / or the second housing 200 may be unsealed housings. For example, there may be openings in the first housing 100 and / or the second housing 200 for the movable contact assembly 110 to move through (enter and exit).

[0066] The first housing 100 and / or the second housing 200 may have openings (similar to or different from the openings described above) to allow (convective) cooling (flow). The first housing 100 (and / or the second housing 200) may include ventilation openings. In an example, the ventilation openings may allow convection of dielectric fluid from outside the first housing 100 through the first housing 100 (and / or the second housing 200, respectively).

[0067] In embodiments that can be combined with other embodiments described herein, openings in the second housing 200 and / or the third housing 300 can also provide arc / current interruption capabilities. For example, the openings in the second housing 200 and / or the third housing 300 can provide (mitigate / improve) the exhaust of hot (contaminated) gases around the contacts (the contact surface between the movable contact assembly 110 and the fixed contact assembly 210). For example, hot (contaminated) gases may be generated during arc / current interruption. In examples, these openings provide (mitigate / improve) the exhaust of hot (contaminated) gases after or during arc / current interruption or contact separation.

[0068] The arc during (arc / current) interruption can (dielectrically) weaken the (dielectric) gas. The (dielectrically) weakened (dielectric) gas can be replaced with fresh gas to (completely) interrupt the current. Therefore, the openings in the second housing 200 and / or the third housing 300 (and / or the fixed contact assembly 210) can provide improved (arc / current) interruption capabilities.

[0069] The first housing 100 and the second housing 200 can be designed to ensure an optimal electric field, for example in the absence of sharp edges and components intended to be maintained at different electrical potentials, for example the first housing 100 and / or components inside the first housing 100 (such as the movable contact assembly 110) should maintain a minimum distance from each other relative to the second housing 200 and / or components inside the second housing 200.

[0070] As already explained, the second housing 200 surrounds the fixed contact assembly 210. The term "surround" (housed / arranged within, etc.) should be interpreted as surrounding or enclosing, and is not intended to define that the second housing 200 forms a sealed enclosure for the fixed contact assembly 210. The same applies to the first housing 100.

[0071] The first housing 100 is at the same electrical potential as the movable contact assembly 110. For example, the first housing 100 may be electrically connected to at least one component inside the first housing 100, such as the first conductive wire 140, the non-flexible conductor 144, and / or the movable contact assembly 110.

[0072] The thermal conductivity of the first housing 100 may be at least 100 W / mK. For example, the thermal conductivity of zinc, aluminum, copper, or an alloy thereof may be at least 100 W / mK. Therefore, heat dissipation can be substantially improved.

[0073] The average (arithmetic) roughness of the outer surface of the first housing 100 or a substantial portion thereof (e.g., at least 50%, 75%, 90%, or 99% of the outer surface) may be between 1 μm and 20 μm, or preferably between 4 μm and 8 μm. The first housing 100 may be made of a metal (e.g., zinc, aluminum, copper, or alloys thereof). The outer surface of the first housing 100 having the roughness defined above may be a metal outer surface of the first housing 100 (the metal surface of the first housing 100 may contribute to the majority of heat dissipation).

[0074] Therefore, the electric field control effect is sufficient / not adversely impaired, while heat dissipation is sufficiently improved. Therefore, compactness is sufficiently improved.

[0075] A second housing 200 may be provided. The second housing 200 may be electrically conductive. The second housing 200 may surround and / or be electrically connected to the fixed contact assembly 210, for example, such that the second housing is at the same electrical potential as the fixed contact assembly 210.

[0076] The embodiments of the first housing 100 may be applied to the second housing 200 with corresponding advantages / effects.

[0077] For example, the second housing 200 may have a minimum radius of curvature as described in the embodiment of the first housing 100. In another example, the second housing 200 may be made of zinc, aluminum, copper, and / or alloys thereof. In another example, the second housing 200 may have an inner surface optimized for heat transfer with the fixed contact assembly 210.

[0078] In another example, the second housing 200 may have a thermal conductivity of at least 100 W / mK. In another example, the second housing 200 may have an outer surface / periphery with an average (arithmetic) roughness in the range of 1 μm to 20 μm, or preferably 4 μm to 8 μm. Thus, heat dissipation is improved and dielectric requirements (e.g., rated voltage) can still be met. For the sake of brevity, further examples of the second housing 200 according to embodiments of the first housing 100 are omitted.

[0079] In an embodiment, a switch device may include a first (conductive) housing 100 and a second (conductive) housing 200. The first housing 100 may enclose a switch actuator mechanism 120. The switch actuator mechanism 120 may be used to actuate a movable contact assembly 110. For example, the actuator mechanism is arranged to move the movable contact assembly between an open state and a closed state. The second housing 200 may enclose a fixed contact assembly 210. The first housing 100 may be arranged at a distance from the second housing 200.

[0080] A (sealed and airtight) housing (of the distribution switchgear) may be provided. The housing may include a through-hole into which a switchgear operating shaft of an electrically insulating material may be inserted. The switchgear operating shaft may be adapted to operate a switch actuator mechanism 120 (for actuating the movable contact assembly 110). The switchgear operating shaft may be configured to rotate about its longitudinal axis to operate the switch actuator mechanism 120. Similarly, if the first housing 100 encloses at least one component of the grounding switch (e.g., the movable grounding contact 440), the grounding switch operating shaft may be disposed.

[0081] The arrangement of the movable contact assembly 110 and the fixed contact assembly 210 at a distance in separate (conductive) housings 100, 200, or the arrangement of at least one actuator mechanism of the movable contact assembly 110, improves the dielectric withstand capability of the switchgear. The electrical insulation level between phases and phase to ground is improved. This reduces the dielectric requirements of the medium surrounding the switchgear. This approach has been shown to replace the commonly used electrical insulating and arc-extinguishing medium SF6 with a medium with lower global warming potential.

[0082] A third housing 300 may be provided. The third housing 300 may be electrically insulating. The movable contact assembly 110 may be adapted to be movable within the third housing 300. The third housing 200 may be disposed between the first housing 100 and the second housing 200.

[0083] The switchgear can be used for distribution switchgear. The switchgear can be used to operate using a dielectric medium (electrically insulating gas). The dielectric medium can be a gas other than SF6. The dielectric medium can be a gas with a global warming potential lower than SF6. The dielectric gas can be air, dry air, or a gas mixture, for example, a gas mixture including an insulating gas with a global warming potential lower than SF6. For example, the dielectric medium can be a gas mixture including an organic fluorine compound selected from the group consisting of fluoroethers, ethylene oxides, fluoroamines, fluoroketones, fluoroolefins, fluoronitriles, and mixtures and / or decomposition products thereof.

[0084] The maximum rated voltage (RMS / AC) of the switchgear may be in the range of 1 kV to 52 kV, preferably 10 kV to 42 kV, and more preferably 12 kV to 24 kV. The AC voltage range of 1 kV to 52 kV may be referred to as medium voltage (MV), see standard EC62271-103. However, all voltages above 1 kV may be referred to as high voltage (HV).

[0085] According to some embodiments, which can be combined with other embodiments described herein, the maximum rated voltage (RMS / AC) of the switchgear may be 18 kV, preferably 16 kV, and most preferably 12 kV. For example, the switchgear may be adapted to operate with (dry) air as the dielectric medium and have a maximum (RMS / AC) voltage of 18 kV, (dry) air and 16 kV, or (dry) air and 12 kV.

[0086] According to some embodiments, which can be combined with other embodiments described herein, the maximum rated voltage (RMS / AC) of the switchgear may be 52 kV, preferably 41 kV, more preferably 36 kV, and most preferably 24 kV. For example, the switchgear may be configured to operate with a gas mixture (having a lower global warming potential than SF6) as a dielectric medium and have a maximum voltage (RMS / AC) of 52 kV, a gas mixture and 41 kV, a gas mixture and 36 kV, or a gas mixture and 24 kV.

[0087] In an example, the switchgear can be suitable for use with (dry) air as the dielectric medium with a maximum voltage (RMS / AC) of 18 kV (or 16 kV or 12 kV) and for use with a gas mixture (with a lower global warming potential than SF6) as the dielectric medium with a maximum voltage (RMS / AC) of 52 kV (or 41 kV, or 36 kV or 24 kV).

[0088] Alternatively, in an embodiment that may be combined with other embodiments described herein, the maximum voltage rating (RMS / AC) of the switchgear may be 26 kV (or 24 kV or 18 kV), and the switchgear may be configured to operate with (dry) air as the dielectric medium. The switchgear may be scaled up. In an example, the switchgear may be larger to increase dielectric withstand capability.

[0089] In another example, the switchgear can be configured to operate with a dielectric gas at a higher pressure to improve dielectric withstand capability. For example, the dielectric gas (e.g., air / dry air) can be at a pressure of at least 1 bar, preferably at least 1.3 bar, more preferably at least 1.5 bar, and most preferably at least 1.7 bar. The higher pressure of the dielectric gas can provide the necessary dielectric withstand for higher maximum voltages (RMS / AC), such as 26 kV, 24 kV, or 18 kV.

[0090] The switchgear described in the embodiments may be a pneumatic switch. The advantage of using a pneumatic switchgear is that it can manage relatively high electrical power at a relatively low cost while reducing the dielectric requirements of the medium surrounding the switchgear. Preferably, the switchgear is a load-break switch and / or a disconnect switch (e.g., in combination with a vacuum interrupter).

[0091] The first housing 100 can provide a structure for mechanical attachment of components (e.g., the movable contact assembly 110) inside the first housing 100. The first housing 100 can provide further mechanical functions. For example, the first housing 100 may include a guide groove. The guide groove may be adapted to guide the longitudinal movement of the movable contact assembly 110 along the axis 112 of the movable contact assembly. Thus, the functions of the mechanical structure (attachment / guidance), the electric field controller, and the heat sink (multiple) can be integrally provided by the first housing 100. As a result, the compactness of the switch device is improved.

[0092] The movable contact assembly 110 may include an arc-resistant inner nozzle and a high-conductivity main contact element. The fixed contact assembly 210 may include an arc-resistant contact pin and a high-conductivity multiple contact element.

[0093] A power distribution switchgear may include a sealed gastight enclosure and a switchgear for operating with a dielectric gas having a global warming potential lower than SF6 inside the sealed gastight enclosure. The switchgear may be according to embodiments described herein.

[0094] exist Figure 1 In the figures, dashed lines are used only to improve clarity, for example, to distinguish between components.

[0095] Further embodiments will be described below.

[0096] According to embodiment 1, a gas-insulated air-blown type switchgear is provided for operating in a sealed airtight enclosure of a power distribution switchgear, the sealed airtight enclosure being filled with a dielectric gas having a global warming potential lower than that of SF6, the switchgear comprising: a fixed contact assembly (210); a movable contact assembly (110) capable of longitudinally moving along an axis (112) of the movable contact assembly between a closed state of the switchgear and an open state of the switchgear, the movable contact assembly (110) being electrically connected to the fixed contact assembly (210) in the closed state of the switchgear, and not electrically connected to the fixed contact assembly (210) in the open state of the switchgear; a switch actuator mechanism (120) for transmitting the rotational movement of the drive shaft to the longitudinal movement of the movable contact assembly (110); an earthing switch; a first terminal (160) electrically connected to the movable contact assembly (110) via a first conductive wire (140), the first conductive wire (140) comprising a A flexible conductor (142) adapted to accommodate longitudinal movement of a movable contact assembly (110), the first terminal (160) being further electrically connected to a grounding switch via a second conductive wire (460); a second terminal electrically connected to a fixed contact assembly (210); a conductive first housing (100) surrounding at least a portion of the movable contact assembly (110) to electrically shield the movable contact assembly (110) when the switch device is in an open state, the first housing (100) further surrounding a switch actuator mechanism (120), the first conductive wire (140), and at least a portion of the grounding switch, wherein the first housing (100) includes a ventilation opening for allowing convection of a dielectric gas from outside the first housing (100) through the first housing (100), and wherein at least a portion of at least one of the first terminal (160), the first conductive wire (140), and the second conductive wire (460) is thermally conductively connected to the first housing (100).

[0097] According to embodiment 2, there is provided the switch device according to embodiment 1, wherein the first housing (100) includes a guide groove for guiding the movable contact assembly (110) to move longitudinally along the axis (112) of the movable contact assembly.

[0098] According to embodiment 3, there is provided the switchgear according to embodiment 1 or 2, wherein the grounding switch is electrically connected to the first housing (100) to ground the first housing (100) when the grounding switch is in a closed state.

[0099] According to embodiment 4, a switching device according to any one of embodiments 1 to 3 is provided, wherein the grounding switch is a knife switch and includes a fixed grounding contact and a movable grounding contact (440), wherein when the grounding switch is in an open state, the movable grounding contact (440) is enclosed in a first housing (100).

[0100] According to embodiment 5, there is provided a switch device according to any one of embodiments 1 to 4, wherein the first housing (100) is electrically connected to the movable contact assembly (110) so as to be at the same electrical potential as the movable contact assembly (110).

[0101] According to embodiment 6, there is provided the switchgear according to any one of embodiments 1 to 5, wherein the first housing (100) has a thermal conductivity of at least 100 W / mK.

[0102] According to embodiment 7, there is provided a switch device according to any one of embodiments 1 to 6, wherein the contact area between the first conductive wire (140) and the first housing (100) is at least 200 mm 2 , preferably at least 400mm 2 .

[0103] According to embodiment 8, there is provided a switch device according to any one of embodiments 1 to 7, wherein the arithmetic mean roughness of the outer surface of the first housing (100) is between 1 μm and 20 μm, preferably between 4 μm and 8 μm.

[0104] According to embodiment 9, a switching device according to any one of embodiments 1 to 8 is provided, wherein the first housing (100) is made of zinc, copper, aluminum or an alloy thereof, and / or the arithmetic mean roughness of the metal outer surface of the first housing (100) is between 1 μm and 20 μm, preferably between 4 μm and 8 μm.

[0105] According to embodiment 10, there is provided the switch device according to any one of embodiments 1 to 9, wherein when the switch device is in an off state, the first housing (100) surrounds the movable contact assembly (110).

[0106] According to embodiment 11, there is provided a switching device according to any one of embodiments 1 to 10, further comprising a second conductive housing (200); the second housing (200) surrounds and is electrically connected to the fixed contact assembly (210) for being at the same electrical potential as the fixed contact assembly (210).

[0107] According to embodiment 12, a switching device according to any one of embodiments 1 to 11 is provided, further comprising a third electrically insulating shell (300), the first movable contact assembly (110) being capable of moving within the third electrically insulating shell (300), and the third shell (300) being arranged between the first shell (100) and the second shell (200).

[0108] According to embodiment 13, a switching device according to any one of embodiments 1 to 12 is provided, wherein the first terminal (160) is connected to the first housing (100) at a first terminal inner portion (160a), or is connected to the first housing (100) between a connection with the first conductive wire (140) or the non-flexible conductor (144) and a first terminal outer portion (160b) or the periphery of the first housing (100).

[0109] According to embodiment 14, a distribution switchgear is provided, comprising a sealed airtight enclosure and a switchgear for operating with a dielectric gas having a global warming potential lower than SF6 within the sealed airtight enclosure, the switchgear being the switchgear according to any one of embodiments 1 to 13.

[0110] According to embodiment 15, there is provided a distribution switchgear according to embodiment 14, wherein the dielectric gas is air, dry air, or an organic fluorine compound selected from the group consisting of fluoroethers, ethylene oxides, fluoroamines, fluoroketones, fluoroolefins, fluoronitriles, and mixtures and decomposition products thereof.

[0111] Reference Numbers

[0112] 100 first shell

[0113] 110 movable contact assembly

[0114] 112 Axis of movable contact assembly

[0115] 120 switch actuator mechanism

[0116] 140 First Conductive Wire

[0117] 142 Flexible Conductor

[0118] 144 Non-flexible conductor

[0119] 160 First terminal

[0120] 160a First terminal inner portion

[0121] 160b First terminal outer portion

[0122] 200 Second shell

[0123] 210 Fixed contact assembly

[0124] 300 Third Shell

[0125] 440 movable ground contact

[0126] 460 Second Conductive Wire

Claims

1. A gas-insulated, air-blown type switchgear for operating within a sealed, airtight enclosure of a power distribution switchgear, said sealed, airtight enclosure being filled with a dielectric gas having a global warming potential lower than that of SF6, said switchgear comprising: a fixed contact assembly (210); A movable contact assembly (110) capable of longitudinally moving along an axis (112) of the movable contact assembly between a closed state of the switch device and an open state of the switch device, wherein the movable contact assembly (110) is electrically connected to the fixed contact assembly (210) in the closed state of the switch device, and the movable contact assembly (110) is not electrically connected to the fixed contact assembly (210) in the open state of the switch device; a switch actuator mechanism (120) for transmitting the rotational movement of the actuation shaft to the longitudinal movement of the movable contact assembly (110); Earthing switch; a first terminal (160) electrically connected to the movable contact assembly (110) via a first conductive wire (140), the first conductive wire (140) comprising a flexible conductor (142) for accommodating the longitudinal movement of the movable contact assembly (110), the first terminal (160) further electrically connected to the grounding switch via a second conductive wire (460); a second terminal electrically connected to the fixed contact assembly (210); a conductive first housing (100) surrounding at least a portion of the movable contact assembly (110) to electrically shield the movable contact assembly (110) when the switch device is in the open state, the first housing (100) further surrounding the switch actuator mechanism (120), the first conductive wire (140), and at least a portion of the grounding switch, wherein the first housing (100) includes a ventilation opening for allowing convection of the dielectric gas through the first housing (100) from outside the first housing (100), and At least a portion of at least one of the first terminal (160), the first conductive wire (140), and the second conductive wire (460) is thermally conductively connected to the first housing (100).

2. The switch device according to claim 1, wherein the first housing (100) comprises a guide groove for guiding the movable contact assembly (110) to move in the longitudinal direction along the axis (112) of the movable contact assembly.

3. The switchgear according to claim 1, wherein the grounding switch is electrically connected to the first housing (100) for grounding the first housing (100) when the grounding switch is in a closed state.

4. The switch device according to claim 1, wherein the grounding switch is a knife switch and comprises a fixed grounding contact and a movable grounding contact (440), wherein when the grounding switch is in an off state, the movable grounding contact (440) is enclosed in the first housing (100).

5. The switch device according to claim 1, wherein the first housing (100) is electrically connected to the movable contact assembly (110) for being at the same electrical potential as the movable contact assembly (110).

6. The switchgear according to claim 1, wherein the first housing (100) has a thermal conductivity of at least 100 W / mK.

7. The switch device according to claim 1, wherein the contact area between the first conductive wire (140) and the first housing (100) is at least 200 mm 2 .

8. The switch device according to claim 1, wherein the arithmetic mean roughness of the outer surface of the first housing (100) is between 1 μm and 20 μm.

9. The switch device according to claim 1, wherein the first shell (100) is made of zinc, copper, aluminum or an alloy thereof, or wherein the arithmetic mean roughness of the metal outer surface of the first shell (100) is between 1 μm and 20 μm, or wherein the first shell (100) is made of zinc, copper, aluminum or an alloy thereof, and the arithmetic mean roughness of the metal outer surface of the first shell (100) is between 1 μm and 20 μm.

10. The switch device according to claim 1, wherein when the switch device is in an off state, the first housing (100) surrounds the movable contact assembly (110).

11. The switch device according to claim 1, further comprising a second conductive housing (200); the second conductive housing (200) surrounds and is electrically connected to the fixed contact assembly (210) so as to be at the same electrical potential as the fixed contact assembly (210).

12. The switch device according to claim 11 further comprises a third electrically insulating housing (300), wherein the movable contact assembly (110) is movable within the third electrically insulating housing (300), and the third electrically insulating housing (300) is arranged between the first housing (100) and the second conductive housing (200).

13. The switch device according to claim 1, wherein the first terminal (160) is connected to the first housing (100) at a first terminal inner portion (160a), or is connected to the first housing (100) between a connection with the first conductive wire (140) or the non-flexible conductor (144) and a first terminal outer portion (160b) or the periphery of the first housing (100).

14. A power distribution switchgear comprising a sealed gastight enclosure and a switchgear for operating with a dielectric gas having a global warming potential lower than that of SF6 inside the sealed gastight enclosure, the switchgear being the switchgear according to claim 1.

15. The distribution switchgear of claim 14, wherein the dielectric gas is air, dry air, or an organic fluorine compound comprising at least one member selected from the group consisting of fluoroethers, ethylene oxides, fluoroamines, fluoroketones, fluoroolefins, fluoronitriles, and mixtures and decomposition products thereof.

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