Transformer and its riser, plug-in unit and conductor connector

Abstract

The present invention relates to a conductor connector, and in particular to a conductor connector for a transformer. In addition, the present invention also relates to a transformer plug-in unit using such a conductor connector, and a transformer riser and a transformer using such a transformer plug-in unit. The conductor connector comprises a cylindrical connector body, a first end that can be connected to the internal lead, and a second end that can be opposite to the bushing, and a circle of side surfaces located between the first end and the second end, wherein the outer edge of the first end has a chamfer, the chamfer is in an arc shape and extends from the first end to the side surface, the outer edge of the second end is provided with a flange protruding axially toward the bushing, the flange is annular, and its surface is in an arc shape, and its radial outer side wall serves as an extension of the side surface, and the contact surface between the connector body and the bushing is located radially inside the flange. The chamfer has the function of dispersing the electric field strength, thereby avoiding the occurrence of local discharge and breakdown caused by field strength concentration, and the flange serves as a shielding layer, which can effectively avoid the influence of electric field concentration at the contact surface.

Description

Technical Field

[0001] The present invention relates to a conductor connector, in particular to a conductor connector for a transformer. In addition, the present invention also relates to a transformer plug-in unit using the conductor connector, and a transformer riser and a transformer using the transformer plug-in unit. Background Art

[0002] In transformers, the internal connection method of plug-in unit leads is usually to use a copper plate that matches the tail of the bushing, such as Figure 1 As shown, a copper plate (100) of the same diameter is fixed to the tail of the bushing (300) by bolts. Because of the large current, the electric field strength is often very high around this connection structure, especially at the edge corners and other locations where the local field strength is concentrated, it is easy to cause local discharge or breakdown, thereby causing a fault. In order to ensure the reliable operation of the transformer, it is usually necessary to design the transformer riser for installing the plug-in unit to have a sufficiently large diameter, thereby increasing the distance between the shell (400) and the electrode to accommodate more insulating medium. When the power frequency withstand voltage is 230kv, the diameter needs to be greater than 550mm, and when the power frequency withstand voltage is 270kv, the diameter needs to be more than 600mm. This not only increases the overall volume and weight of the product, but also increases the cost.

[0003] At the same time, since the copper plate (100) and the sleeve tail (300) are fixed by bolts, the protruding bolt head (110) often becomes another location where the field strength is concentrated, and each bolt needs to be equipped with a shielding cap (120), which further increases the complexity of the structure and also increases the material cost, time cost and control cost of production and installation. Summary of the invention

[0004] The object of the present invention is to provide a conductor connector for connecting a bushing and an internal lead in a transformer, which has a good function of dispersing the electric field strength and a good shielding function, so that the diameter of the transformer riser can be reduced. The conductor connector includes a cylindrical connector body, a first end that can be connected to the internal lead, and a second end that can be opposite to the bushing, and a circle of side surfaces located between the first end and the second end, wherein the outer edge of the first end has a chamfer, the chamfer is in the shape of a circular arc and extends from the first end to the side surface. The chamfer has the function of dispersing the electric field strength, thereby avoiding the occurrence of local discharge and breakdown caused by field strength concentration.

[0005] According to one aspect of the conductor connector of the present invention, the outer edge of the second end is provided with a flange protruding axially toward the sleeve, the flange is annular, and its surface is arc-shaped, and has a circle of radial inner sidewall and a circle of radial outer sidewall extending axially, the radial outer sidewall is an extension of the side surface, and the contact surface between the connector body and the sleeve is located radially inside the flange. The flange acts as a shielding layer, which can effectively avoid the influence of electric field concentration at the contact surface.

[0006] According to another aspect of the conductor connector of the present invention, the flange portion covers the side wall of the sleeve, and a gap exists between the radial inner side wall and the side wall of the sleeve.

[0007] According to another aspect of the conductor connector of the present invention, the chamfers, side surfaces and flange outer surfaces of the connector body are all covered with an insulating layer which may be insulating paper.

[0008] According to another aspect of the conductor connector of the present invention, the connector body is provided with at least two axial screw holes for bolt fixing, the screw holes extend from the first end to the second end, and have a section with a diameter larger than the bolt head near the first end for accommodating the bolt head.

[0009] The present invention also aims to provide a transformer plug-in unit, comprising an internal lead, a bushing and the above-mentioned conductor connector, wherein the internal lead is fixedly connected to the bushing through the connector, and the three are coaxially arranged.

[0010] The purpose of the present invention is further to provide a transformer riser, comprising a riser shell and the above-mentioned transformer plug-in unit arranged in the riser shell, the riser shell having a cylindrical cavity, the transformer plug-in unit being arranged along the geometric axis of the cavity, wherein the riser shell has a diameter less than 500 mm.

[0011] The present invention further aims to provide a transformer, which comprises the above-mentioned transformer plug-in unit and / or the above-mentioned transformer riser. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of a transformer plug-in unit in the prior art;

[0013] Figure 2a and 2b is a three-dimensional schematic diagram of a conductor connector according to the present invention;

[0014] Figure 3 is a schematic diagram of a conductor connector according to the present invention after being coated with insulating paper;

[0015] Figure 4is a three-dimensional schematic diagram of a transformer plug-in unit according to the present invention;

[0016] Figure 5 is a cross-sectional schematic diagram of a transformer plug-in unit according to the present invention;

[0017] Figure 6 It is a three-dimensional schematic diagram of the transformer riser according to the present invention.

[0018] Description of symbols

[0019] 100 Copper Plate

[0020] 110 Bolt head

[0021] 120 Shielding Cap

[0022] 300 Casing tail

[0023] 400 Housing

[0024] 1 Conductor connector

[0025] 2 Internal leads

[0026] 3 Casing

[0027] 4-Liter Raised Seat Housing

[0028] 11 Connector body

[0029] 12 First End

[0030] 13 Second End

[0031] 14 Side

[0032] 15 Chamfer

[0033] 16 Flange

[0034] 17 Radial inner wall

[0035] 18 Contact surface

[0036] 19 Screw holes

[0037] 20 Insulation layer DETAILED DESCRIPTION

[0038] The specific implementation of the present invention is described below in conjunction with the accompanying drawings.

[0039] The conductor connector 1 of the present invention comprises a connector body 11 and a first end 12 and a second end 13 axially opposite to each other. Figure 2a and Figure 2b The axial ends of the conductor connector 1 of a preferred embodiment of the present invention are shown. Figure 2aAs shown, the conductor connector 1 has an arc-shaped chamfer 15 between the first end 12 connected to the internal lead 2 and the side 14, so that along the end surface of the first end 12 to the side 14, at any position, the conductor connector 1 has a large radius of curvature, so on the surface of the conductor connector, especially in the corner area from the first end 12 to the side 14, the charge will not be gathered in certain parts due to the effect of the field strength, and the electric field strength will not be too large in certain parts. In this embodiment, the curvature radius of the chamfer 15 is not less than 10 mm, and the preferred value is 12 mm.

[0040] like Figure 2b and Figure 5 As shown, the conductor connector has an axially protruding flange 16 on the second end 13 opposite to the sleeve. Compared with the copper plate in the prior art having a diameter matching the sleeve tail, the conductor connector in this embodiment has a diameter slightly larger than the sleeve tail, and the portion surrounded by the annular flange 16 on the second end 13 has a diameter matching the sleeve tail 3. Therefore, as shown in FIG. Figure 5 As shown, after the conductor connector and the sleeve are fixed to each other, the mating surface 103 of the two is enclosed within the flange 16, and there is a gap between the radial inner wall 17 of the flange 16 and the side wall of the sleeve. Because the mating surface needs to consider the matching of the contact surface, chamfers cannot be introduced to avoid the generation of electric field strength concentration areas, so the field strength at the edge of the contact surface 18 is higher than other parts. In this embodiment, the annular flange 16 covers the radial outer side of the contact surface 18 with a gap, which plays the role of a shielding layer, so that the high-intensity electric field at the edge of the contact surface is blocked, avoiding local discharge and breakdown. Similarly, in order to avoid field strength concentration on the flange 16 itself, the flange 16 has an arc shape.

[0041] Another example Figure 2a As shown, the conductor connector in this embodiment has four screw holes 19, which are used to be fixed to the tail of the sleeve 3 by bolts. The bolts penetrate from the first end 12 to the second end 13 and fasten the conductor connector 1 to the tail of the sleeve 3. At the first end of the screw hole 19, there is a section with a diameter larger than the bolt head, and its depth is slightly larger than the axial dimension of the bolt head. When the bolt is tightened, the bolt head is completely sunken inside the conductor connector 1, so any protruding part extending out of the connector is avoided. Due to structural and functional limitations, the bolt head must have some shape structures that will cause field strength concentration, and being completely sunken inside the conductor connector can make these parts of field strength concentration be shielded by the conductor connector, and also eliminate the necessity of adding a shielding cap to the bolt as in the prior art.

[0042] like Figure 3As shown, in another preferred embodiment of the present invention, the chamfer 15 on the first end 12 of the conductor connector, the side 14 and the flange 16 on the second end 13 are all covered by the insulating layer 20, thereby further increasing the shielding effect and the insulating effect. The insulating layer 20 in this embodiment is made of insulating paper, and other various insulating layers can also be substituted.

[0043] Another embodiment of the present invention is Figure 4 and Figure 5 As shown, the transformer plug-in unit has the conductor connector 1 in the aforementioned embodiment. When viewed from a side perspective, the first end 12 of the conductor connector connected to the internal lead 2 and the second end 13 of the conductor connector facing the bushing have no edges or corners that easily cause field concentration. The contact surface 18 between the bushing 3 and the conductor connector 1 is completely blocked by the flange 16, and there is a gap between the side wall of the bushing 3 and the flange 16 to form a shield. At the same time, the fixing bolts are completely invisible at the first end 12 of the conductor connector 1 from a side perspective.

[0044] Another embodiment of the present invention is Figure 6 As shown, the transformer plug-in unit is located inside the housing 4 of the transformer riser, the housing is filled with insulating liquid, and the plug-in unit is located at the geometric axis position in the center of the riser housing 4. Due to the chamfering and shielding design of the conductor connector, under the same power frequency withstand voltage condition, the diameter of the housing 4 of the riser can be reduced. When the power frequency withstand voltage is 230kv, the diameter of the riser housing can be about 450mm, and when the power frequency withstand voltage is 270kv, the diameter can be about 500mm.

[0045] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be regarded as a limitation of the present invention. After reading the above content, various modifications and substitutions of the present invention will be obvious to those skilled in the art. Therefore, the scope of protection of the present invention should be defined by the appended claims. In addition, any figure marks in the claims should not be regarded as limiting the claims involved. The word "comprising" does not exclude devices or steps not listed in other claims or the specification; words such as "first" and "second" are only used to indicate names, and do not indicate any specific order. In this article, "parallel", "vertical", etc. are not strict mathematical and / or geometric limitations, but also include errors that can be understood by those skilled in the art and are allowed by manufacturing or use.

Claims

1. A conductor connector (1) for connecting a bushing (3) and an internal lead (2) in a transformer, comprising: A connector body (11) which is cylindrical and has a first end surface (12) connected to the internal lead (2), a second end surface (13) in contact with the sleeve (3), and a circle of side surfaces (14) located between the first end surface and the second end surface; The outer edge of the first end surface (12) has a chamfer (15), and the chamfer (15) is in an arc shape and extends from the first end surface to the side surface (14). The connector body (11) is provided with at least two axial screw holes (19) for bolting to the rear end of the sleeve (3); the screw holes (19) extend from the first end face (12) to the second end face (13), and have a section with a diameter larger than the bolt head at a portion close to the first end face (12) for accommodating the bolt head; and the depth of the screw holes at the first end face is greater than the axial dimension of the bolt head.

2. The conductor connector according to claim 1, wherein: The chamfer (15) has a curvature radius of not less than 10 mm.

3. The conductor connector according to claim 1, wherein: The outer edge of the second end surface (13) is provided with a flange (16) protruding axially toward the sleeve (3); the flange (16) is annular and has an arc-shaped surface and has an axially extending radial inner wall (17) and a radial outer wall; the radial outer wall serves as an extension of the side surface (14); and a contact surface (18) between the connector body (11) and the sleeve (3) is located radially inside the flange (16).

4. The conductor connector according to claim 3, wherein: The flange (16) partially covers the side wall of the sleeve, and a gap exists between the radial inner side wall (17) and the side wall of the sleeve.

5. The conductor connector according to claim 4, wherein: The chamfers, side surfaces and flange outer surfaces of the connector body are all covered with an insulating layer (20).

6. The conductor connector according to claim 5, wherein: The insulating layer is insulating paper.

7. A transformer plug-in unit, comprising an internal lead (2), a bushing (3) and a conductor connector (1) according to any one of claims 1 to 6, wherein the internal lead (2) is fixedly connected to the bushing (3) through the conductor connector (1), and the three are coaxially arranged.

8. A transformer riser, comprising a riser housing (4) and a transformer plug-in unit according to claim 7 arranged in the riser housing (4), wherein the riser housing (4) has a cylindrical cavity, and the transformer plug-in unit is arranged along the geometric axis of the cavity, wherein the riser housing (4) has a diameter less than 500 mm.

9. A transformer comprising the transformer plug-in unit according to claim 7 and / or the transformer riser according to claim 8.

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