On-load tap changer for transformers

Abstract

The utility model relates to transformer accessory technical field discloses the on-load tap changer of transformer, its installation is in the top side of transformer oil tank, include: the tap changer casing, its inside has the installation cavity, its bottom side is equipped with a plurality of first conductive contact piece, a plurality of first conductive contact piece two two a group, is provided with six groups;The contact mounting seat is rotationally arranged in the installation cavity, and the bottom side has a plurality of convex parts, a plurality of convex parts all are equipped with second conductive contact piece, and the second conductive contact piece has contact groove;The utility model, corresponding two first conductive contact piece embeds in the contact groove of second conductive contact piece, guarantees corresponding two first conductive contact piece and second conductive contact piece stable contact of sticking, reduces two first conductive contact piece and second conductive contact piece contact area reduction problem, and two first conductive contact piece and second conductive contact piece stable contact of sticking can guarantee the voltage regulation accuracy of transformer, makes the adjustment output voltage.

Description

Technical Field

[0001] This utility model relates to the technical field of transformer accessories, and in particular to on-load tap changers for transformers. Background Technology

[0002] The on-load tap changer is one of the core accessories of a transformer. If it is an unloaded tap changer, its core feature is that it can switch the taps when the transformer is unloaded (power off), and adjust the turns ratio by changing the winding ratio, thereby adjusting the output voltage.

[0003] Existing off-grid tap changers are operated by opening the tap changer operating cover on the transformer tank, exposing the tap selector. The selector's lever is manually rotated to switch from the current tap slot to the target tap slot. This causes the conductive contacts to rotate, achieving contact between them to switch taps, change the winding turns ratio, adjust the transformer ratio, and thus regulate the output voltage. However, during prolonged rotation and adjustment of the off-grid tap changer, stress can easily cause insufficient contact between the two conductive contacts, reducing the contact area and increasing contact resistance. This change in contact resistance affects the transformer's voltage regulation accuracy, leading to output voltage fluctuations. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides an on-load tap changer for transformers to solve the aforementioned problems.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The on-load tap changer for the transformer is installed on the top side of the transformer tank and includes: The tap changer housing has an internal mounting cavity, and a number of first conductive contacts are mounted on its bottom side. The first conductive contacts are arranged in pairs, and there are six pairs. The contact mounting base is rotatably disposed in the mounting cavity. It has several protrusions on its bottom side, and a second conductive contact is mounted on each of the protrusions. The second conductive contact has a contact groove, and three sets of corresponding first conductive contacts are embedded and attached to the contact grooves of the corresponding second conductive contacts. Several limiting components are disposed on the bottom side of the tap changer housing. The limiting components are configured to limit the first conductive contact embedded in the contact groove of the second conductive contact.

[0006] Preferably, a gear scale ring is fixedly installed on the top side of the tap changer housing. The gear scale ring has a plurality of gear slots, the number of the plurality of first conductive contacts is twice the number of gear slots, and the number of the plurality of gear slots is consistent with the number of the plurality of limit components.

[0007] Preferably, a mounting ring is fixedly mounted on the top of the contact mounting base, and a lever is rotatably mounted on the mounting ring. One end of the lever is deflected and inserted into the corresponding gear slot.

[0008] Preferably, each of the several first conductive contacts on the bottom side of the tap changer housing is provided with a wiring terminal, and the wiring terminals of the several first conductive contacts are electrically connected to the corresponding wire connectors of the transformer windings.

[0009] Preferably, the limiting component includes: The mounting post, whose top end is fixedly installed on the bottom side of the tap changer housing, is located between the two corresponding first conductive contacts and is made of thermosetting plastic, such as epoxy resin. Two limiting plates are fixedly installed on one side of the mounting column, with a gap between the two limiting plates. The second conductive contact is embedded in the gap between the two limiting plates, and two corresponding first conductive contacts are embedded in the contact grooves of the second conductive contacts. The limiting plates are made of thermosetting plastic, such as epoxy resin.

[0010] Preferably, the two sides of the second conductive contact are arranged in an arc shape, and the two end sidewalls of the two limiting plates are also arranged in an arc shape.

[0011] Preferably, the outer surface of the tap changer housing has an external threaded groove, and the top side of the tap changer housing is provided with an internal threaded top cylinder. The inner wall of the internal threaded top cylinder is respectively provided with a limit ring and a sealing ring. The internal threaded top cylinder is threadedly installed on the external threaded groove on the outer surface of the tap changer housing, and the inner wall of the limit ring abuts against the side wall of the deflected lever. The inner ring of the sealing ring is sealed and fitted on the top outer surface of the tap changer housing.

[0012] This application provides several limiting components on the bottom side of the tap changer housing. When the adjusted position of several second conductive contacts on the bottom side of the contact mounting base is adjusted by rotation, the second conductive contacts are embedded in the gap between the two limiting plates, and the corresponding two first conductive contacts are embedded in the contact grooves of the second conductive contacts. This ensures stable contact between the corresponding two first conductive contacts and the second conductive contacts, reducing the problem of reduced contact area between the two first conductive contacts and the second conductive contacts. The stable contact between the two first conductive contacts and the second conductive contacts can ensure the voltage regulation accuracy of the transformer, thus enabling adjustment of the output voltage. Attached Figure Description

[0013] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a schematic diagram of the structure of the present invention in cross-section of the first plane; Figure 3This is a partial cross-sectional structural diagram of the present invention; Figure 4 This is a partial cross-sectional view of the bottom of the present invention. Figure 5 This is a partial cross-sectional view of the structure of this utility model from an exploded perspective; Figure 6 This is a schematic diagram of the structure of the present invention in cross-section of the second plane; Figure 7 This is a partial cross-sectional view of the tap changer housing of this utility model. Figure 8 This is a structural schematic diagram of the contact mounting base of this utility model from a perspective.

[0014] In the diagram: 100, tap changer housing; 101, mounting cavity; 102, external thread groove; 110, first conductive contact; 1101, terminal block; 120, position scale ring; 1201, position groove; 200, contact mounting base; 210, protrusion; 220, second conductive contact; 2201, contact groove; 230, mounting ring; 2301, lever; 300, limit assembly; 310, mounting post; 320, limit plate; 400, internal thread top cylinder; 410, limit ring; 420, sealing ring. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] During prolonged rotation and adjustment of a no-load tap changer, stress can easily cause insufficient contact between the two contacting conductive contacts, reducing the cross-sectional area between them. This increases contact resistance, and changes in contact resistance affect the voltage regulation accuracy of the transformer, leading to output voltage fluctuations. To address this problem, this embodiment discloses an on-load tap changer for a transformer, installed on the top side of the transformer tank, comprising: Figure 1 The tap changer housing 100 shown; as Figure 8 The contact mounting base 200 shown; as Figure 7 The shown are several limit components 300.

[0017] like Figure 1As shown, a number of first conductive contacts 110 are installed on the bottom side of the contact mounting base 200. The first conductive contacts 110 are arranged in pairs, with six pairs in total. At the same time, each of the first conductive contacts 110 is provided with a terminal block 1101. The terminal blocks 1101 of the first conductive contacts 110 are electrically connected to the corresponding wire connectors of the transformer windings.

[0018] like Figure 7 As shown, in order to install the contact mounting base 200 into the tap changer housing 100, the tap changer housing 100 has a mounting cavity 101. The contact mounting base 200 is rotatably disposed in the mounting cavity 101. Its bottom side has several protrusions 210, and each of the protrusions 210 is equipped with a second conductive contact piece 220. The cross-section of the second conductive contact piece 220 is U-shaped, and the second conductive contact piece 220 has a contact groove 2201. The cross-section of the contact groove 2201 is U-shaped. At the same time, the two sides of the second conductive contact piece 220 are arc-shaped, and three sets of corresponding first conductive contacts 110 are embedded and attached to the contact groove 2201 of the corresponding second conductive contact piece 220.

[0019] Continue as Figure 7 As shown, several limiting components 300 are disposed on the bottom side of the tap changer housing 100. The limiting components 300 are configured to limit the first conductive contact 110 embedded in the contact groove 2201 of the second conductive contact 220. The limiting assembly 300 includes: a mounting post 310 and two limiting plates 320; the top end of the mounting post 310 is fixedly mounted on the bottom side of the tap changer housing 100, located between two corresponding first conductive contacts 110, and is made of thermosetting plastic, such as epoxy resin, which has excellent insulation properties and mechanical strength; both limiting plates 320 are fixedly mounted on one side of the mounting post 310, with a gap between the two limiting plates 320, and both end sidewalls of the two limiting plates 320 are arc-shaped to facilitate the second conductive contact 220 being embedded into the gap between the two limiting plates 320 during rotation. Within the gap between the two limiting plates 320, the corresponding two first conductive contacts 110 are embedded in the contact grooves 2201 of the second conductive contacts 220, ensuring stable contact between the corresponding two first conductive contacts 110 and the second conductive contacts 220. This reduces the problem of reduced contact area between the two first conductive contacts 110 and the second conductive contacts 220. Stable contact between the two first conductive contacts 110 and the second conductive contacts 220 can ensure the voltage regulation accuracy of the transformer, enabling adjustment of the output voltage. The limiting plates 320 are made of thermosetting plastics, such as epoxy resin, which has excellent insulation properties and mechanical strength.

[0020] like Figure 5As shown, a position scale ring 120 is fixedly installed on the top side of the tap changer housing 100. The position scale ring 120 has a number of position slots 1201. The number of first conductive contacts 110 is twice the number of position slots 1201. The number of position slots 1201 is the same as the number of limit components 300.

[0021] Continue as Figure 5 As shown, a mounting ring 230 is fixedly mounted on the top of the contact mounting base 200. A lever 2301 is rotatably mounted on the mounting ring 230. One end of the lever 2301 is deflected and inserted into the corresponding position slot 1201. By manually rotating and adjusting the lever 2301, the contact mounting base 200 can be rotated and adjusted within the mounting cavity 101 of the tap changer housing 100, thereby realizing the rotational position adjustment of several second conductive contacts 220 on the bottom side of the contact mounting base 200.

[0022] like Figure 5 As shown, the outer surface of the tap changer housing 100 has an external threaded groove 102, and an internal threaded top cylinder 400 is provided on the top side of the tap changer housing 100. The inner wall of the internal threaded top cylinder 400 is provided with a limit ring 410 and a sealing ring 420 respectively. The internal threaded top cylinder 400 is threadedly installed on the external threaded groove 102 on the outer surface of the tap changer housing 100, and the inner wall of the limit ring 410 abuts against the side wall of the deflected lever 2301. The inner ring of the sealing ring 420 is sealed and fitted on the top outer surface of the tap changer housing 100. When the internal threaded top cylinder 400 is screwed on the top outer surface of the tap changer housing 100, on the one hand, the position of the lever 2301 can be limited and fixed, and on the other hand, the sealing ring 420 inside the internal threaded top cylinder 400 can prevent rainwater from entering the top of the tap changer housing 100.

[0023] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0024] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention.

Claims

1. An on-load tap changer for a transformer, which is installed on the top side of the transformer tank, characterized in that, include: The tap changer housing (100) has a mounting cavity (101) inside, and a number of first conductive contacts (110) are mounted on its bottom side. The number of first conductive contacts (110) are arranged in pairs, and there are six groups. The contact mounting base (200) is rotatably disposed in the mounting cavity (101), and has several protrusions (210) on its bottom side. Each of the protrusions (210) is equipped with a second conductive contact (220). The second conductive contact (220) has a contact groove (2201). Three sets of corresponding first conductive contacts (110) are embedded and fitted in the contact groove (2201) of the corresponding second conductive contact (220). Several limiting components (300) are disposed on the bottom side of the tap changer housing (100). The limiting components (300) are configured to limit the first conductive contact (110) embedded in the contact groove (2201) of the second conductive contact (220).

2. The on-load tap changer for transformers according to claim 1, characterized in that, A gear scale ring (120) is fixedly installed on the top side of the tap changer housing (100). The gear scale ring (120) has a number of gear slots (1201). The number of first conductive contacts (110) is twice the number of gear slots (1201). The number of gear slots (1201) is the same as the number of limit components (300).

3. The on-load tap changer for transformers according to claim 2, characterized in that, The top of the contact mounting base (200) is fixedly mounted with a mounting ring (230), and a lever (2301) is rotatably mounted on the mounting ring (230). One end of the lever (2301) is deflected and inserted into the corresponding gear slot (1201).

4. The transformer on-load tap changer according to claim 1, characterized in that, A terminal block (1101) is provided on each of the first conductive contacts (110) on the bottom side of the tap changer housing (100). The terminal blocks (1101) of the first conductive contacts (110) are electrically connected to the corresponding wire connectors of the transformer windings.

5. The on-load tap changer for a transformer according to claim 1, characterized in that, The limiting component (300) includes: Mounting post (310), the top of which is fixedly mounted on the bottom side of tap changer housing (100), is located between two corresponding first conductive contacts (110), and is made of thermosetting plastic, such as epoxy resin. Two limiting plates (320) are fixedly installed on one side of the mounting post (310), and there is a gap between the two limiting plates (320). The second conductive contact (220) is embedded in the gap between the two limiting plates (320), and two corresponding first conductive contacts (110) are embedded in the contact groove (2201) of the second conductive contact (220). The limiting plates (320) are made of thermosetting plastic, such as epoxy resin.

6. The transformer on-load tap changer according to claim 5, characterized in that, The two sides of the second conductive contact (220) are arranged in an arc shape, and the two end sidewalls of the two limiting plates (320) are also arranged in an arc shape.

7. The transformer on-load tap changer according to claim 1, characterized in that, The outer surface of the tap changer housing (100) has an external threaded groove (102). An internal threaded top cylinder (400) is provided on the top side of the tap changer housing (100). The inner wall of the internal threaded top cylinder (400) is provided with a limit ring (410) and a sealing ring (420). The internal threaded top cylinder (400) is threadedly installed on the external threaded groove (102) on the outer surface of the tap changer housing (100). The inner wall of the limit ring (410) abuts against the side wall of the deflected lever (2301). The inner ring of the sealing ring (420) is sealed and fitted on the top outer surface of the tap changer housing (100).

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