Fixed contact assembly, arc extinguish chamber and high-voltage circuit breaker

Abstract

The utility model relates to a fixed contact assembly, an arc extinguish chamber and a high-voltage circuit breaker. The fixed contact assembly comprises a fixed contact and a fixed contact support attached to the fixed contact, the fixed contact support is provided with at least one first opening, and the fixed contact is exposed through the first opening so as to be directly communicated with the outside of the fixed contact support.

Description

Technical Field

[0001] The present disclosure generally relates to a fixed contact assembly for an arc extinguishing chamber of a high-voltage circuit breaker, an arc extinguishing chamber including the fixed contact assembly, and a high-voltage circuit breaker including the arc extinguishing chamber. Background Art

[0002] Circuit breakers have been widely used in high voltage circuit breaking applications. Typically, in a circuit equipped with a circuit breaker, upon detecting a fault condition or fault current, the circuit breaker can be operated to interrupt the current flowing therein, thereby interrupting the current flowing in the circuit. In some high voltage circuit breaking applications, the rated or nominal current flowing through the circuit breaker may be as high as 6300A or 8000A.

[0003] When carrying nominal current, ohmic heat may be generated in the circuit breaker. Higher nominal currents usually cause greater thermal loads or thermal stresses on the components in the circuit breaker. For example, Figure 7 A typical temperature distribution of a circuit breaker chamber at high nominal current load (e.g. up to 6300 A or 8000 A) is shown in . For example, the moving side of the arc extinguishing chamber in the circuit breaker (i.e. the highlighted area) is one of the hot zones with an average temperature rise above 65 / 75K.

[0004] It is well known that high thermal stresses may lead to degradation of the insulation material and potentially other failures. This limits the current carrying capacity of the circuit breaker. Therefore, the ohmic heating generated when carrying high nominal currents is one of the main issues in circuit breaker design. There is a need to provide improved thermal management for circuit breaker design to reduce the internal heat load of the circuit breaker, especially on the moving side of the arc extinguishing chamber. Moreover, it would be beneficial to perform such improved thermal management without making other major modifications to the current breaker design or requiring complex design changes, such as increasing the cross-section of the current path or using highly conductive materials, such as copper, etc., which may involve higher costs. Utility Model Content

[0005] It is therefore an object of the present disclosure to provide an improved fixed contact assembly within an arc extinguishing chamber of a high voltage circuit breaker to minimize heat generation and enhance heat dissipation while maintaining, at least to some extent, a relatively low cost design or effortless modification.

[0006] In view of this, a fixed contact assembly for an arc extinguishing chamber of a high-voltage circuit breaker is provided. In addition, an arc extinguishing chamber including the fixed contact assembly and a high-voltage circuit breaker including the arc extinguishing chamber are provided. The various aspects, advantages and features of the present disclosure are apparent from the claims, the specification and the drawings.

[0007] According to one aspect of the present disclosure, a fixed contact assembly for an arc extinguishing chamber of a high-voltage circuit breaker is provided. The fixed contact assembly includes: a fixed contact, and a fixed contact bracket to which the fixed contact is attached, wherein the fixed contact bracket is provided with at least one first opening, and the fixed contact is exposed through the first opening, so as to be directly connected to the outside of the fixed contact bracket.

[0008] According to another aspect of the present disclosure, an arc extinguishing chamber is provided. The arc extinguishing chamber includes a fixed contact assembly, the fixed contact assembly includes: a fixed contact, a fixed contact bracket to which the fixed contact is attached, wherein the fixed contact bracket is provided with at least one first opening, the fixed contact is exposed through the first opening, and is directly connected to the outside of the fixed contact bracket, and a movable contact assembly, the movable contact assembly includes a movable contact that is matched to and can move relative to the fixed contact.

[0009] According to another aspect of the present disclosure, a high-voltage circuit breaker including an arc extinguishing chamber is provided. The arc extinguishing chamber includes a fixed contact assembly, the fixed contact assembly including: a fixed contact, a fixed contact bracket to which the fixed contact is attached, wherein the fixed contact bracket is provided with at least one first opening, the fixed contact is exposed through the first opening, and is directly connected to the outside of the fixed contact bracket, and a movable contact assembly, the movable contact assembly including a movable contact that is matched to and can move relative to the fixed contact. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Embodiments of the invention are illustrated by way of example and not limitation in the figures of the accompanying drawings in which like references indicate similar elements.

[0011] Figure 1 A cross-sectional view of an arc extinguishing chamber of a high voltage circuit breaker according to the present disclosure is shown.

[0012] Figure 2A-2B A perspective view of a fixed contact support is shown, wherein Figure 2A The fixed contact bracket in the prior art is shown. Figure 2B An improved stationary contact support having a first opening according to one embodiment of the present disclosure is shown.

[0013] Figures 3A-3C A perspective view of the flange is shown, wherein Figure 3A The flange in the prior art is shown. Figure 3B shows an improved flange with a second opening according to one embodiment of the present disclosure, Figure 3C An improved flange having a second opening is shown according to another embodiment of the present disclosure.

[0014] Figures 4A-4B A perspective view of a stationary contact is shown, wherein Figure 4AThe fixed contact in the prior art is shown. Figure 4B An improved stationary contact having an increased number of finger contacts according to one embodiment of the present disclosure is shown.

[0015] Figure 5 A stationary contact support having a plurality of fins according to one embodiment of the present disclosure is shown.

[0016] Figure 6 A cross-sectional view of an arc extinguishing chamber of a high voltage circuit breaker according to one embodiment of the present disclosure is shown to indicate the anodized surfaces of the fixed contact support and the flange.

[0017] Figure 7 The temperature distribution of a prior art circuit breaker chamber under high nominal current load is shown.

[0018] Figure 8 The circuit breaker chamber according to the present disclosure has ventilation openings on both the fixed contact support and the flange. Figure 7 Temperature distribution at the same high nominal current load.

[0019] Fig. 9 A computational fluid dynamics (CFD) simulation diagram showing natural convection in a circuit breaker chamber according to the present disclosure is shown. DETAILED DESCRIPTION

[0020] Reference will now be made in detail to various embodiments of the present disclosure, one or more examples of which are illustrated in the accompanying drawings. In the following description of the drawings, like reference numerals refer to like parts.

[0021] Although the following description is given for high-voltage circuit breakers, in particular for high-rated or nominal current applications (e.g., up to 6300A or 8000A), it should be understood that the embodiments of the present disclosure are not limited thereto. On the contrary, the present embodiment can be applied to any place where a circuit breaker is needed. The circuit breaker can be a puffer type circuit breaker, a self-explosive circuit breaker, a combined gas-assisted self-explosive circuit breaker, a generator circuit breaker, a disconnect switch, a combined disconnect switch and circuit breaker, a live tank circuit breaker, or a load-breaking switch in a power transmission and distribution system.

[0022] Figure 1 An arc extinguishing chamber 100 of a high voltage circuit breaker according to the present disclosure is shown. The arc extinguishing chamber 100 includes a fixed contact assembly 110 on the right and a movable contact assembly 120 on the left.

[0023] exist Figure 1In the illustrated embodiment, the fixed contact assembly 110 includes a fixed main contact 111 and a fixed arc contact 112. The fixed main contact 111 is attached to a fixed contact holder 113, and the fixed contact holder 113 is mounted to a fixed contact support 114. A flange 115 is also provided for connecting the fixed contact support 114 to the intermediate insulator 130, and the fixed contact assembly 110 on the left and the movable contact assembly 120 on the right are connected to each other via the flange. The flange 115 is positioned around the fixed contact holder 113 to form a part of the housing of the arc extinguishing chamber 100.

[0024] The fixed main contact 111 may also be referred to as a nominal contact. The fixed main contact may be designed using any type of contact, such as a finger-type contact, a spiral-type contact, and a thin-sheet-type contact.

[0025] Go to Figure 1 On the right side shown, the movable contact assembly 120 includes a movable main contact 121 and a movable arc contact 122. A piston 123 and other related components are provided to support the movable main contact 121 and the movable arc contact 122, so that the movable main contact 121 and the movable arc contact 122 can be respectively moved relative to the fixed main contact 111 and the fixed arc contact 112 in the open position ( Figure 1 The circuit breaker is a device that moves between an open position and a closed end position (not shown), wherein the relative fixed contacts and movable contacts are completely electrically or galvanically separated from each other in the open position, and the relative fixed contacts and movable contacts are physically in contact with each other in the closed end position, and current can flow through them. Therefore, the circuit breaker can interrupt the circuit, thereby interrupting the flow of current in the circuit, and / or extinguishing the arc generated when the circuit is interrupted.

[0026] In addition, the circuit breaker may also include other components, such as a puffer type cylinder, a self-spraying chamber, a pressure collecting space, a compression space or a gas filling volume, an expansion space, a driver, a controller, etc., some of which are omitted in the figure. These components are provided in a manner similar to that of a conventional circuit breaker.

[0027] As mentioned above, ohmic heating may be generated in the circuit breaker when carrying current. Figure 7One of the hot zones shown (i.e., the highlighted area) can be formed in the arc extinguishing chamber. In order to reduce the heat load or thermal stress of the components in the hot zone, the circuit breaker according to the present disclosure is combined with at least one ventilation opening on the fixed contact support, so that the fixed main contact attached thereto is exposed, thereby directly communicating with the outside of the fixed contact support. The exposure of the fixed main contact allows the contact to directly dissipate heat to the outside, rather than performing contact heat exchange through the fixed contact support. In addition, the circuit breaker according to the present disclosure is also combined with at least one ventilation opening on the flange, which is close to at least one first opening of the fixed contact support. By providing at least one ventilation opening on both the fixed contact support and the flange, a flow channel is established between the inside and the outside of the circuit breaker, so that the fixed main contact can be directly communicated with the outside of the housing via at least one second opening provided on the flange and at least one first opening provided on the fixed contact support. A cooling fluid flow (e.g., an air flow) can flow through the flow channel to allow convective heat exchange of components such as the fixed main contact, thereby further enhancing heat dissipation.

[0028] Figure 1 1 shows an embodiment of a circuit breaker with ventilation openings. As shown in the figure, a first opening 1130 is provided on the fixed contact support 113 to expose the fixed main contact 111 attached thereto. A second opening 1150 is provided on the flange 115 near the first opening 1130. Figure 1 As shown by the arrows in , the flow channel 140 is formed between the inside and the outside of the circuit breaker 100 through the first opening 1130 and the second opening 1150. The fixed main contact attached to the fixed contact bracket 113 can be directly connected to the outside of the housing via the flow channel. A cooling fluid flow (e.g., air flow) can flow through the flow channel 140 to perform direct convection heat exchange with components on the flow channel 140 (e.g., the fixed main contact 111).

[0029] For example, Figure 8 As shown, by combining the ventilation openings on the fixed contact bracket and the flange, Figure 7 At the same high nominal current load, the average temperature on the mobile side (i.e. the highlighted area) is reduced by about 10-15K. In addition, Fig. 9 A computational fluid dynamics (CFD) simulation diagram is shown, which shows the Figure 7 Natural convection in the circuit breaker compartment at the same high nominal current load. Fig. 9 As shown by the arrows in , the natural convection near the ventilation opening is more active than the rest, further enhancing the heat dissipation.

[0030] It can be understood that the ventilation opening can be arranged in any part of the component that needs to dissipate heat, provided that direct communication with the outside of the component can be established via the ventilation opening.

[0031] Reference Figures 2A to 3C , exemplary configurations of the fixed contact holder and the flange according to the present disclosure will be described below.

[0032] According to some embodiments, the stationary contact support includes a hollow support body. The stationary main contact is attached to an inner surface of the support body. Figure 2B A preferred embodiment of a fixed contact support having a plurality of first openings is further shown. Figure 2B As shown, the fixed contact support 113 has a hollow support body 1131 which is substantially cylindrical. Figure 2A Compared with the fixed contact support 113' in the prior art shown in the figure, the fixed contact support 113 is provided with sixteen first openings 1130, which are evenly distributed on the inner surface 1132 of the cylindrical hollow support body 1131. The first openings help to transfer the heat generated on the fixed main contact 111 to the outside of the fixed contact support 113. Preferably, each first opening 1130 is in the shape of a slit. Other shapes are also possible, including circular, oval, square, etc. The fixed main contact ( Figure 2B The first opening 1130 is exposed to the outside through each first opening 1130. For example, the shape of the first opening 1130 is similar to that of the fixed main contact, so as to achieve the largest possible exposure under the condition of the same opening area.

[0033] According to some embodiments, the flange comprises a hollow flange body, in particular a flange having a substantially cylindrical shape. Figure 3A Different from the flange 115' in the prior art shown in the figure, according to the embodiment of the present disclosure, at least one second opening 1150 is further provided on the flange body of the flange. Figure 3B In one embodiment shown, the at least one second opening 1150 includes two large second openings 2150 symmetrically arranged around the central axis of the flange body 2151. Figure 3C In another embodiment shown, the at least one second opening 1150 includes two groups of second openings 3150 symmetrically arranged around the central axis of the flange body 3151. Each group of second openings includes more than one small opening, for example, five small openings.

[0034] Understandably, Figures 2A-3C The structures of the fixed contact support and flange shown in are illustrative. The fixed contact support and flange according to the present disclosure can have any suitable structure depending on the specific application. In addition, the arrangement of the ventilation openings on the fixed contact support and flange can be changed, provided that a flow channel can be established between the interior and exterior of the circuit breaker via the ventilation openings.

[0035] In addition to enhancing heat dissipation through ventilation openings, the present disclosure also proposes minimizing heat generation by reducing contact resistance.

[0036] According to some embodiments, the stationary main contact may include a plurality of finger-type contacts. Figure 4B The preferred arrangement of the plurality of finger contacts can be shown in FIG. The plurality of finger contacts 1110 of the fixed main contact 111 are divided into a plurality of groups spaced apart from each other along the circumferential direction of the fixed contact support 113. The gap between any two directly adjacent groups in the plurality of groups is smaller than the size of any one of the plurality of groups in the circumferential direction. In this manner, as Figure 4A As shown, the number of finger contacts 1110 is much greater than the number of finger contacts 1110' in the prior art. The increase in the number of finger contacts reduces the contact resistance, thereby also reducing the heat generation. Figure 4B As shown, each of the groups of the plurality of finger contacts 1110 is disposed corresponding to a corresponding one of the first openings 1130 on the fixed contact support 113 , so that the contacts can have a larger area exposed to the outside.

[0037] It can be understood that the plurality of finger contacts can be of any number and arranged in any manner as long as the contact resistance can be reduced.

[0038] Additionally or alternatively, Figure 5 As shown, the present disclosure proposes adding a plurality of fins 1140 to the surface of the fixed contact support 114, on which the flange 115 is assembled. By means of the plurality of fins 1140, the heat dissipation capability can be enhanced.

[0039] To further enhance the heat dissipation capability, at least a portion of the outer surface of the fixed contact support and / or at least a portion of the outer surface of the flange is anodized. Anodizing surface treatment can change the surface radiation efficiency, thereby improving the heat dissipation capability of the anodized area. Figure 6 The anodized surfaces of the stationary contact support 114 and the flange 115 are shown in phantom lines according to one embodiment of the present disclosure.

[0040] The present disclosure also provides an arc extinguishing chamber and a high voltage circuit breaker including the fixed contact assembly as described above.

[0041] In the previous description, various embodiments and aspects of the present disclosure have been described with reference to the accompanying drawings. The above description and the accompanying drawings are illustrative of the present disclosure and should not be construed as limiting the present disclosure. Many specific details are described to provide a thorough understanding of the various embodiments of the present disclosure. However, in some cases, in order to provide a concise discussion of the embodiments of the present disclosure, well-known or conventional details are not described.

[0042] It is understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish an element, component, region, layer or part. Therefore, without departing from the teachings of the present invention, the above-mentioned first element, component, region, layer or part can be referred to as a second element, component, region, layer or part.

[0043] For ease of description, spatially relative terms such as "below", "below", "low", "below", "above", and "above" may be used herein to describe the relationship of one element or feature to another element and feature as shown in the figure. It will be understood that in addition to the orientation shown in the figure, the spatially relative terms are also intended to cover different orientations of the device in use or operation. For example, if the device in the figure is turned over, the element or feature described as "below" or "below" or "below" is oriented as "above" the element or feature. Therefore, the exemplary terms "below" and "below" can include both above and below orientations. Terms such as "before" or "before" and "after" or "subsequently" can also be used similarly, for example, to indicate the order in which light passes through the elements. The device can be oriented in other ways (rotated 90 degrees or other directions), and the spatially relative descriptors used herein can also be interpreted accordingly. In addition, it can also be understood that when a layer is referred to as "between" two layers, it can be the only layer between the two layers, or one or more intermediate layers can also be present.

[0044] The terms used herein are only used to describe specific embodiments and are not intended to limit the present invention. Unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" used herein also include plural forms. It can also be understood that the terms "include" and / or "comprise" used in this specification specify the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more related listed items.

[0045] It is understood that when an element or layer is referred to as being "on," "connected to," "coupled to," or "adjacent to" another element or layer, it may be directly on, connected to, coupled to, or adjacent to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on," "directly connected to," "directly coupled to," or "directly adjacent to" another element or layer, there are no intervening elements or layers. However, in any case, "on" or "directly on" should not be interpreted as requiring that one layer completely cover the underlying layer.

[0046] Embodiments of the invention are described herein with reference to schematic diagrams of idealized embodiments (and intermediate structures) of the invention. Therefore, the shapes illustrated may vary due to manufacturing techniques and / or tolerances. Therefore, embodiments of the invention should not be understood as being limited to the specific shapes of the regions described herein, but should include shape deviations that occur, for example, during manufacturing. Therefore, the regions shown in the figures are schematic, and their shapes are not intended to illustrate the actual shapes of the device regions, nor to limit the scope of the invention.

[0047] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. It is also understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having the same meaning as that in the context of the relevant technology and / or this specification, and will not be interpreted as idealized or overly formal unless explicitly defined herein.

Claims

1. A fixed contact assembly for an arc extinguishing chamber of a high voltage circuit breaker, characterized in that: include: Fixed contacts; a fixed contact holder to which the fixed contact is attached; as well as a flange around the fixed contact support to form a part of the housing of the arc extinguishing chamber, The fixed contact support is provided with at least one first opening, and the fixed contact is exposed through the first opening, so as to be directly connected with the outside of the fixed contact support. The flange is provided with at least one second opening arranged close to the at least one first opening, so that the fixed contact is directly connected to the outside of the shell via the at least one second opening arranged on the flange and the at least one first opening arranged on the fixed contact bracket.

2. The fixed contact assembly according to claim 1, characterized in that: in, The fixed contact bracket includes a hollow bracket body; and The fixed contact is attached to an inner surface of the bracket body.

3. The fixed contact assembly according to claim 2, characterized in that: in, The stent body has a generally cylindrical shape; and The at least one first opening includes a plurality of first openings.

4. The fixed contact assembly according to claim 3, characterized in that: in, The at least one first opening includes sixteen first openings evenly distributed on the inner surface.

5. The fixed contact assembly according to claim 1, characterized in that: in, The flange includes a hollow flange body; and The at least one second opening is disposed on the flange body.

6. The fixed contact assembly according to claim 5, characterized in that: in, The flange body has a generally cylindrical shape; and The at least one second opening includes two groups of second openings symmetrically arranged around a central axis of the flange body.

7. The fixed contact assembly according to claim 6, characterized in that: in, Each group of second openings includes one or more second openings.

8. The fixed contact assembly according to claim 7, characterized in that: in, Each group of second openings includes five second openings.

9. The fixed contact assembly according to any one of claims 1 to 8, characterized in that: in, The fixed contact includes a plurality of finger-type contacts.

10. The fixed contact assembly according to claim 9, characterized in that: in, The plurality of finger contacts are divided into a plurality of groups, and each of the plurality of groups is disposed corresponding to a respective one of the at least one first opening.

11. The fixed contact assembly according to claim 10, characterized in that: in, The plurality of groups are spaced apart from each other along a predetermined direction, and a gap between any two directly adjacent groups among the plurality of groups in the predetermined direction is smaller than a size of any one of the plurality of groups.

12. The fixed contact assembly according to any one of claims 1 to 8, characterized in that: in, The fixed contact is a fixed main contact.

13. The fixed contact assembly according to any one of claims 1 to 8, characterized in that: in, The fixed contacts are nominal contacts.

14. The fixed contact assembly according to any one of claims 1 to 8, characterized in that: Also includes, a fixed contact support to which the flange is mounted; and Wherein, the flange is mounted on the surface of the fixed contact support member provided with a plurality of fins.

15. The fixed contact assembly according to claim 14, characterized in that: in, At least a portion of an outer surface of the stationary contact support is anodized.

16. The fixed contact assembly according to claim 14, characterized in that: in, At least a portion of an outer surface of the flange is anodized.

17. The fixed contact assembly according to any one of claims 1 to 8, characterized in that: in, The at least one first opening is in the shape of a slit.

18. An arc extinguishing chamber, characterized in that: include: Fixed contact assembly and movable contact assembly, Wherein, the fixed contact assembly comprises: Fixed contacts; a fixed contact holder to which the fixed contact is attached; and a flange around the fixed contact support to form a part of the shell of the arc extinguishing chamber, wherein the fixed contact support is provided with at least one first opening, and the fixed contact is exposed through the first opening so as to be directly connected with the outside of the fixed contact support; The flange is provided with at least one second opening disposed close to the at least one first opening, so that the fixed contact is directly connected to the outside of the housing via the at least one second opening disposed on the flange and the at least one first opening disposed on the fixed contact bracket. Wherein, the movable contact assembly comprises: A movable contact is fitted to the fixed contact and is movable relative to the fixed contact.

19. A high voltage circuit breaker, comprising an arc extinguishing chamber, characterized in that: in, The arc extinguishing chamber comprises: Fixed contact assembly and movable contact assembly, Wherein, the fixed contact assembly comprises: Fixed contacts; a fixed contact holder to which the fixed contact is attached; and a flange around the fixed contact support to form a part of the housing of the arc extinguishing chamber, Wherein, the fixed contact bracket is provided with at least one first opening, and the fixed contact is exposed through the first opening, so as to be directly connected with the outside of the fixed contact bracket; The flange is provided with at least one second opening disposed close to the at least one first opening, so that the fixed contact is directly connected to the outside of the housing via the at least one second opening disposed on the flange and the at least one first opening disposed on the fixed contact bracket. Wherein, the movable contact assembly comprises: A movable contact is fitted to the fixed contact and is movable relative to the fixed contact.

Images