A type of UHV converter station connecting hardware and UHV converter station

Abstract

This invention relates to the field of converter stations, specifically to a UHV converter station connection fitting and a UHV converter station. The UHV converter station connection fitting includes a copper clamp for fixed connection to the terminals of a wall bushing and at least two sets of terminal block assemblies for fixed connection to split conductors. Each terminal block assembly includes an aluminum terminal block and an aluminum pressure block fixed to the aluminum terminal block. The aluminum terminal block is fixedly connected to the copper clamp. The aluminum terminal block has a terminal block contact surface, and the copper clamp has a clamp contact surface that makes conductive contact with the corresponding terminal block contact surface. Both the clamp contact surface and the terminal block contact surface are plated with a metal plating to prevent electrochemical corrosion between the two contact surfaces. Designing the clamp for fixed connection to the terminals as a copper clamp increases the current carrying capacity and effectively reduces the temperature rise of the wall bushing and connection fitting. The metal plating on the clamp contact surface and the terminal block contact surface prevents electrochemical corrosion between the two contact surfaces.

Description

Technical Field

[0001] This invention relates to the field of converter stations, specifically to a UHV converter station connection fitting and a UHV converter station. Background Technology

[0002] In ultra-high voltage converter stations, the terminals of the wall bushings are copper conductors, typically cylindrical in shape, with aluminum stranded wires as the split conductors. The terminals of the wall bushings are usually connected to the individual aluminum stranded wires via fittings to achieve current shunting. The connection points between the wall bushing terminals and the fittings are the main sources of heat generation.

[0003] Traditional connecting hardware is mostly made of one-piece aluminum casting. To prevent electrochemical corrosion, the terminals of the through-wall bushing and the connecting hardware generally achieve conductive contact in the following two ways:

[0004] One method is to use a copper-silver plated and aluminum-silver plated connection. The current carrying capacity of the copper-silver plated and aluminum-silver plated contact surface is controlled at 0.0936 A / mm². 2 This is far less than the 0.12 A / mm² current carrying capacity at the contact surface of a copper-copper conductor. 2 During peak summer electricity consumption periods, if the converter station operates at full load for extended periods, excessive temperature rise may occur at the terminals and connection points of the wiring hardware, forcing the converter station to reduce its load to avoid damage to the wall bushings due to excessive temperature.

[0005] Secondly, a copper-aluminum transition sleeve is used for connection, such as the split conductor T-connection conversion hardware disclosed in Chinese invention patent with authorization announcement number CN105024184B. By setting a copper-aluminum transition sleeve between the terminal and the connecting hardware, the original one contact surface becomes two contact surfaces. This increases the contact resistance and can also easily cause the temperature rise value at the connection between the terminal and the connecting hardware to exceed the standard. Summary of the Invention

[0006] The purpose of this invention is to provide a connection fitting for an ultra-high voltage converter station to solve the problem that the connection fitting in the prior art easily causes the temperature rise value of the terminal block and the connection point of the connection fitting to exceed the standard; the purpose of this invention is also to provide an ultra-high voltage converter station to solve the above problems.

[0007] To achieve the above objectives, the technical solution for the UHV converter station connection hardware of the present invention is as follows:

[0008] The UHV converter station connection fittings include copper clamps for fixed connection to the terminals of the wall bushings and at least two sets of terminal block assemblies for fixed connection to the split conductors. The terminal block assembly includes an aluminum terminal block and an aluminum pressure block fixed on the aluminum terminal block. The aluminum terminal block is fixedly connected to the copper clamp. The aluminum terminal block has a terminal block contact surface, and the copper clamp has a clamp contact surface that makes conductive contact with the corresponding terminal block contact surface. Both the clamp contact surface and the terminal block contact surface are plated with a metal plating to prevent electrochemical corrosion between the two contact surfaces.

[0009] The beneficial effects are as follows: Since the main heat-generating area is at the connection point between the connecting hardware and the terminal block, the clamp fixed to the terminal block is designed as a copper clamp to increase the current carrying capacity. With the same conductive contact area, copper-copper conductive contact can achieve a greater current-carrying capacity, effectively reducing the temperature rise of the wall bushing and connecting hardware. Because the copper clamp and aluminum terminal block are made of different materials, metal plating is formed on the contact surfaces of both the clamp and the terminal block to prevent electrochemical corrosion between the two contact surfaces. Since the contact point between the clamp and the terminal block is a current shunt point, a copper-plated silver-plated aluminum connection method can also ensure current carrying capacity. Furthermore, the connecting hardware adopts a split structure, which not only facilitates processing but also effectively increases the heat dissipation area of ​​the connecting hardware, improving radiative heat dissipation efficiency and further reducing the temperature rise of the wall bushing and connecting hardware.

[0010] As a further improvement, the copper clamp includes a clamp body and a fixing plate disposed on the outer side of the clamp body, wherein the clamp contact surface is disposed on the fixing plate.

[0011] The beneficial effect is that this design allows the size of the fixing plate to be designed according to the flow rate, so as to ensure the flow capacity.

[0012] As a further improvement, the fixing plate has the aforementioned clamp contact surface on both sides; the aluminum terminal block includes a first fixing plate segment, a second fixing plate segment and a middle plate segment, the first fixing plate segment and the second fixing plate segment are arranged in parallel, the middle plate segment is connected between the two fixing plate segments, the terminal block contact surface is set on the first fixing plate segment, and the aluminum pressure block is fixed on the second fixing plate segment.

[0013] The beneficial effects are: since aluminum terminal blocks are fixed on both sides of the fixing plate, and the aluminum terminal blocks are designed into three sections, after the split wires are fixed by the aluminum terminal blocks and aluminum pressure blocks, the distance between the split wires will not be too close, ensuring that the split wires will not interfere with each other.

[0014] As a further improvement, the angle between the first fixed plate segment and the intermediate plate segment, as well as the angle between the second fixed plate segment and the intermediate plate segment, are both greater than or equal to 90°.

[0015] The beneficial effect is that this design can reduce stress concentration problems.

[0016] As a further improvement, the clamp body includes two half clamps and two fixing plates, which are respectively set in the middle of the two half clamps.

[0017] The beneficial effect is that this design makes the connector suitable for four-split conductors.

[0018] As a further improvement, the metal plating is a silver plating or a tin plating.

[0019] The beneficial effect is that silver has good electrical conductivity, which helps to improve current carrying capacity.

[0020] As a further improvement, each aluminum terminal block corresponds to at least two spaced aluminum pressure blocks.

[0021] The beneficial effect is that this design, while ensuring the stability of the split wires, is conducive to heat dissipation.

[0022] As a further improvement, countersunk holes are provided on both the aluminum pressure block and the aluminum terminal block.

[0023] The beneficial effect is that the countersunk hole can enclose the bolt head and nut to form a good anti-corona effect.

[0024] As a further improvement, the aluminum pressure block is provided with a first half-groove, and the aluminum terminal block is provided with a second half-groove. The first half-groove and the second half-groove form a fixing groove for fixing the split wires; the groove walls of the first half-groove and / or the second half-groove are provided with machining marks.

[0025] The beneficial effect is that this design increases the friction between the split wire and the fixing groove, ensuring the stability of the split wire after it is fixed.

[0026] To achieve the above objectives, the technical solution for the ultra-high voltage converter station of this invention is as follows:

[0027] The ultra-high voltage converter station includes wall bushings, connecting hardware, and split conductors. The connecting hardware includes copper clamps fixedly connected to the terminals of the wall bushings and at least two sets of terminal block assemblies fixedly connected to the split conductors. The terminal block assemblies include aluminum terminal blocks and aluminum pressure blocks fixed to the aluminum terminal blocks. The aluminum terminal blocks are fixedly connected to the copper clamps. The aluminum terminal blocks have terminal block contact surfaces, and the copper clamps have clamp contact surfaces that make conductive contact with the corresponding terminal block contact surfaces. Both the clamp contact surfaces and the terminal block contact surfaces are plated with a metal coating to prevent electrochemical corrosion between the two contact surfaces.

[0028] The beneficial effects are as follows: Since the main heat-generating area is at the connection point between the connecting hardware and the terminal block, the clamp fixed to the terminal block is designed as a copper clamp to increase the current carrying capacity. With the same conductive contact area, copper-copper conductive contact can achieve a greater current-carrying capacity, effectively reducing the temperature rise of the wall bushing and connecting hardware. Because the copper clamp and aluminum terminal block are made of different materials, metal plating is formed on the contact surfaces of both the clamp and the terminal block to prevent electrochemical corrosion between the two contact surfaces. Since the contact point between the clamp and the terminal block is a current shunt point, a copper-plated silver-plated aluminum connection method can also ensure current carrying capacity. Furthermore, the connecting hardware adopts a split structure, which not only facilitates processing but also effectively increases the heat dissipation area of ​​the connecting hardware, improving radiative heat dissipation efficiency and further reducing the temperature rise of the wall bushing and connecting hardware.

[0029] As a further improvement, the copper clamp includes a clamp body and a fixing plate disposed on the outer side of the clamp body, wherein the clamp contact surface is disposed on the fixing plate.

[0030] The beneficial effect is that this design allows the size of the fixing plate to be designed according to the flow rate, so as to ensure the flow capacity.

[0031] As a further improvement, the fixing plate has the aforementioned clamp contact surface on both sides; the aluminum terminal block includes a first fixing plate segment, a second fixing plate segment and a middle plate segment, the first fixing plate segment and the second fixing plate segment are arranged in parallel, the middle plate segment is connected between the two fixing plate segments, the terminal block contact surface is set on the first fixing plate segment, and the aluminum pressure block is fixed on the second fixing plate segment.

[0032] The beneficial effects are: since aluminum terminal blocks are fixed on both sides of the fixing plate, and the aluminum terminal blocks are designed into three sections, after the split wires are fixed by the aluminum terminal blocks and aluminum pressure blocks, the distance between the split wires will not be too close, ensuring that the split wires will not interfere with each other.

[0033] As a further improvement, the angle between the first fixed plate segment and the intermediate plate segment, as well as the angle between the second fixed plate segment and the intermediate plate segment, are both greater than or equal to 90°.

[0034] The beneficial effect is that this design can reduce stress concentration problems.

[0035] As a further improvement, the clamp body includes two half clamps and two fixing plates, which are respectively set in the middle of the two half clamps.

[0036] The beneficial effect is that this design makes the connector suitable for four-split conductors.

[0037] As a further improvement, the metal plating is a silver plating or a tin plating.

[0038] The beneficial effect is that silver has good electrical conductivity, which helps to improve current carrying capacity.

[0039] As a further improvement, each aluminum terminal block corresponds to at least two spaced aluminum pressure blocks.

[0040] The beneficial effect is that this design, while ensuring the stability of the split wires, is conducive to heat dissipation.

[0041] As a further improvement, countersunk holes are provided on both the aluminum pressure block and the aluminum terminal block.

[0042] The beneficial effect is that the countersunk hole can enclose the bolt head and nut to form a good anti-corona effect.

[0043] As a further improvement, the aluminum pressure block is provided with a first half-groove, and the aluminum terminal block is provided with a second half-groove. The first half-groove and the second half-groove form a fixing groove for fixing the split wires; the groove walls of the first half-groove and / or the second half-groove are provided with machining marks.

[0044] The beneficial effect is that this design increases the friction between the split wire and the fixing groove, ensuring the stability of the split wire after it is fixed. Attached Figure Description

[0045] Figure 1 This is a front view of the UHV converter station connection hardware of the present invention;

[0046] Figure 2 for Figure 1 The left view;

[0047] Figure 3 for Figure 1 Top view;

[0048] Figure 4 for Figure 1 Axonometric view;

[0049] Figure 5 for Figure 4 Schematic diagram of the middle half-clamp;

[0050] Figure 6 for Figure 4 A schematic diagram of the structure of the Zhonglv terminal block.

[0051] In the diagram: 11. Half clamp; 12. Fixed edge; 13. First bolt; 14. Fixed plate; 15. Second bolt; 16. Aluminum terminal block; 17. Third bolt; 18. Aluminum pressure block; 19. First half groove; 20. Second half groove; 21. First fixed plate segment; 22. Middle plate segment; 23. Second fixed plate segment; 24. Terminal block contact surface; 25. Clamp contact surface. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0053] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0054] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, terms such as "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 a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Additionally, the terms "front," "rear," "upper," "lower," "left," and "right" are based on the orientation and positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention, not to indicate that the referred device or component must have a specific orientation, and therefore should not be construed as limiting the invention.

[0055] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0056] Example 1 of the UHV converter station connection fittings of the present invention:

[0057] like Figures 1 to 4 As shown, the UHV converter station connection hardware includes copper clamps and terminal block assemblies fixed on the copper clamps. The copper clamps are used to fix and connect to the terminals of the through-wall bushings. The terminal block assemblies are provided in four sets and are used to fix and connect to the split conductors to divert the current of the through-wall bushings to each split conductor.

[0058] like Figure 4 and Figure 5As shown, the copper clamp includes a clamp body and a fixing plate 14. The clamp body is composed of two half clamps 11. The two ends of the two half clamps 11 are respectively provided with fixing edges 12. The fixing edges 12 are provided with fixing holes. The two half clamps 11 are fixed to the wiring terminals of the through-wall sleeve by the first bolt 13.

[0059] In this embodiment, two fixing plates 14 are provided, and the two fixing plates 14 are respectively provided on the outer side of the middle position of the two half clamps 11. Both sides of the fixing plate 14 are provided with clamping contact surfaces 25, and the clamping contact surfaces 25 are plated with a metal plating layer. Preferably, the metal plating layer is a silver plating layer.

[0060] like Figure 4 and Figure 6 As shown, the terminal block assembly includes an aluminum terminal block 16 and an aluminum pressure block 18 fixed on the aluminum terminal block 16. The aluminum terminal block 16 is fixed to the fixing plate 14 by a second bolt 15. The aluminum terminal block 16 has a terminal block contact surface 24 that makes conductive contact with the corresponding clamp contact surface 25. The terminal block contact surface is plated with a metal plating layer, preferably a silver plating layer. By forming a metal plating layer on the clamp contact surface 25 and the terminal block contact surface 24, electrochemical corrosion between the two contact surfaces is prevented, while ensuring current carrying capacity. It should be noted that since the connection position between the fixing plate 14 and the aluminum terminal block 16 is a current shunt point, the copper-silver-aluminum-silver connection method can also ensure current carrying capacity.

[0061] In this embodiment, the aluminum terminal block 16 includes a first fixed plate segment 21, a second fixed plate segment 23, and an intermediate plate segment 22. The first fixed plate segment 21 and the second fixed plate segment 23 are arranged in parallel, and the intermediate plate segment 22 connects the two fixed plate segments. The terminal block contact surface 24 is disposed on the first fixed plate segment 21, and the aluminum pressure block 18 is fixed on the second fixed plate segment 23. The angles between the first fixed plate segment 21 and the intermediate plate segment 22, and between the second fixed plate segment 23 and the intermediate plate segment 22, are both greater than 90°.

[0062] In this embodiment, the distance between the two first fixing plate segments 21 of the two aluminum terminal blocks 16 fixed on both sides of the same fixing plate 14 is less than the distance between the two second fixing plate segments 23. This design ensures that the split wires are not too close together, thus preventing mutual interference between them.

[0063] In this embodiment, the aluminum pressure block 18 has a first semi-groove 19, and the second fixing plate segment 23 has a second semi-groove 20. After the aluminum pressure block 18 is fixed to the second fixing plate segment 23 by the third bolt 17, the first semi-groove 19 and the second semi-groove 20 form a fixing groove for fixing the split wire. The axial direction of the fixing groove is the same as the axial direction of the copper clamp. The second semi-groove 20 has machining marks to increase the friction between the split wire and the fixing groove, ensuring the stability of the fixed split wire. In other embodiments, machining marks can be provided in the first semi-groove.

[0064] In this embodiment, each second fixing plate segment 23 corresponds to at least two aluminum pressure blocks 18. Preferably, each second fixing plate segment 23 corresponds to three aluminum pressure blocks 18, and the three aluminum pressure blocks 18 are arranged at intervals to facilitate heat dissipation. Both the second fixing plate segment 23 and the aluminum pressure blocks 18 are provided with countersunk holes, which can cover the bolt heads and nuts to form a good anti-corona effect.

[0065] After the design of the connection hardware for this ultra-high voltage converter station is completed, it has the following advantages:

[0066] (1) The current-carrying overlap area between the connecting hardware and the wall bushing is determined by the terminal area of ​​the wall bushing. Since the material used for the connection between the connecting hardware and the terminal is copper, the current-carrying density of a copper-copper connection is 0.12 A / mm². 2 This is significantly higher than the 0.0936 A / mm value of the copper-plated silver-aluminum-plated silver contact used in traditional hardware. 2 With the same conductive contact area, copper-copper connections can achieve greater current carrying capacity, effectively reducing the temperature rise of wall bushings and connecting hardware.

[0067] (2) The contact area between the terminal block of the connecting hardware and the fixing plate of the copper clamp is determined by the designer. That is, the size of the contact area is designed according to the calculated current density to ensure the current flow capacity here and avoid this place becoming the weak point of the current flow of the whole hardware, so that the whole hardware can obtain a greater current flow capacity.

[0068] (3) Replacing the integral hardware with multiple separate parts can effectively increase the heat dissipation area of ​​the connecting hardware, improve the efficiency of radiative heat dissipation, and reduce the temperature rise of the through-wall bushing and connecting hardware.

[0069] (4) The copper clamp is made by bending a copper plate and welding it to a fixing plate. The terminal block is made by casting. The production cost of bending copper plates is lower than that of casting. This set of hardware uses four identical terminal blocks, and each terminal block is small. The mold cost used in casting production is lower than that of traditional integral hardware molds. Therefore, the production cost of the hardware provided by this invention is lower than that of traditional integrally cast hardware.

[0070] This invention can meet the connection requirements of wall bushings and four-split conductors in UHVDC converter stations. It is easy to install and aesthetically pleasing. It can effectively increase the current carrying capacity of fittings under a certain contact area, increase the heat dissipation area, and reduce the temperature rise of fittings under a certain current. This ensures that the temperature rise of wall bushings and connecting fittings does not exceed the standard under long-term full-load operation of the converter station, thereby indirectly ensuring the reliable operation of the power grid.

[0071] Example 2 of the UHV converter station connection fittings of the present invention:

[0072] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, the copper clamp includes a clamp body and a fixing plate disposed on the outer side of the clamp body, and the clamp contact surface is disposed on the fixing plate. In this embodiment, the copper clamp includes a clamp body and an end plate disposed at one axial end of the clamp body, but no fixing plate is provided. The clamp contact surface is disposed on the end plate. The copper clamp has the structure of a busbar clamp disclosed in Chinese invention patent application CN104362444A, and multiple aluminum terminal blocks are fixed at intervals along the circumference of the copper clamp on the end plate.

[0073] Example 3 of the UHV converter station connection fittings of the present invention:

[0074] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, the clamping contact surface is provided on both sides of the fixing plate. In this embodiment, the clamping contact surface is only provided on one side of the fixing plate, in which case the wiring board can be a straight board.

[0075] Example 4 of the UHV converter station connection fittings of the present invention:

[0076] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, the angles between the first fixed plate segment and the intermediate plate segment, as well as the angles between the second fixed plate segment and the intermediate plate segment, are both greater than 90°. In this embodiment, the angles between the first fixed plate segment and the intermediate plate segment, as well as the angles between the second fixed plate segment and the intermediate plate segment, are both equal to 90°. In other embodiments, the angles between the first fixed plate segment and the intermediate plate segment, as well as the angles between the second fixed plate segment and the intermediate plate segment, can be slightly less than 90°, such as 80°-90°.

[0077] Example 5 of the UHV converter station connection fittings of the present invention:

[0078] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, the metal plating layer was a silver plating layer, while in this embodiment, the metal plating layer is a tin plating layer.

[0079] Example 6 of the UHV converter station connection fittings of the present invention:

[0080] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, each second fixed plate segment corresponds to at least two aluminum pressure blocks. In this embodiment, each second fixed plate segment corresponds to one aluminum pressure block, and the length of the aluminum pressure block is adapted to the length of the second fixed plate segment.

[0081] The present invention relates to an embodiment of an ultra-high voltage converter station. The ultra-high voltage converter station in this embodiment includes a wall bushing, connecting hardware, and split conductors. The connecting hardware has the same structure as any one of the embodiments 1 to 6 of the above-mentioned ultra-high voltage converter station connecting hardware, and will not be described again here.

[0082] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. Connection fittings for ultra-high voltage converter stations, characterized in that, The device includes a copper clamp for fixed connection with the terminal block of a wall bushing and at least two sets of terminal block assemblies for fixed connection with split wires. The terminal block assembly includes an aluminum terminal block (16) and an aluminum pressure block (18) fixed on the aluminum terminal block (16). The aluminum terminal block (16) is fixedly connected to the copper clamp. The aluminum terminal block (16) has a terminal block contact surface (24), and the copper clamp has a clamp contact surface (25) that makes conductive contact with the corresponding terminal block contact surface (24). Both the clamp contact surface (25) and the terminal block contact surface (24) are plated with a metal plating layer to prevent electrochemical corrosion between the two contact surfaces. The copper clamp includes a clamp body and a fixing plate (14) disposed on the outer side of the clamp body. The clamp contact surface (25) is disposed on the fixing plate (14).

2. The UHV converter station connection fittings according to claim 1, characterized in that, The clamping contact surface (25) is provided on both sides of the fixing plate (14); the aluminum terminal block (16) includes a first fixing plate section (21), a second fixing plate section (23) and a middle plate section (22). The first fixing plate section (21) and the second fixing plate section (23) are arranged in parallel, and the middle plate section (22) is connected between the two fixing plate sections. The terminal block contact surface (24) is set on the first fixing plate section (21), and the aluminum pressure block (18) is fixed on the second fixing plate section (23).

3. The UHV converter station connection fittings according to claim 2, characterized in that, The angle between the first fixed plate segment (21) and the middle plate segment (22) and the angle between the second fixed plate segment (23) and the middle plate segment (22) are both greater than or equal to 90°.

4. The UHV converter station connection fittings according to any one of claims 1 to 3, characterized in that, The clamp body includes two half clamps (11), and two fixing plates (14) are provided, with the two fixing plates (14) respectively located in the middle of the two half clamps (11).

5. The UHV converter station connection fittings according to any one of claims 1 to 3, characterized in that, The metal plating is silver plating.

6. The UHV converter station connection fittings according to any one of claims 1 to 3, characterized in that, Each aluminum terminal block (16) corresponds to at least two spaced aluminum pressure blocks (18).

7. The UHV converter station connection fittings according to any one of claims 1 to 3, characterized in that, Both the aluminum pressure block (18) and the aluminum terminal block (16) are provided with countersunk holes.

8. The UHV converter station connection fittings according to any one of claims 1 to 3, characterized in that, The aluminum pressure block (18) is provided with a first half groove (19), and the aluminum terminal block (16) is provided with a second half groove (20). The first half groove (19) and the second half groove (20) form a fixing groove for fixing the split wires; the groove walls of the first half groove (19) and / or the second half groove (20) are provided with cutting tool marks.

9. An ultra-high voltage converter station, comprising wall bushings, connecting hardware, and split conductors, characterized in that, The connecting fitting includes a copper clamp for fixed connection with the terminal block of the wall bushing and at least two sets of terminal block assemblies for fixed connection with the split wire. The terminal block assembly includes an aluminum terminal block (16) and an aluminum pressure block (18) fixed on the aluminum terminal block (16). The aluminum terminal block (16) is fixedly connected to the copper clamp. The aluminum terminal block (16) has a terminal block contact surface (24), and the copper clamp has a clamp contact surface (25) that makes conductive contact with the corresponding terminal block contact surface (24). Both the clamp contact surface (25) and the terminal block contact surface (24) are plated with a metal plating layer to prevent electrochemical corrosion between the two contact surfaces. The copper clamp includes a clamp body and a fixing plate (14) disposed on the outer side of the clamp body. The clamp contact surface (25) is disposed on the fixing plate (14).

10. The ultra-high voltage converter station according to claim 9, characterized in that, The clamping contact surface (25) is provided on both sides of the fixing plate (14); the aluminum terminal block (16) includes a first fixing plate section (21), a second fixing plate section (23) and a middle plate section (22). The first fixing plate section (21) and the second fixing plate section (23) are arranged in parallel, and the middle plate section (22) is connected between the two fixing plate sections. The terminal block contact surface (24) is set on the first fixing plate section (21), and the aluminum pressure block (18) is fixed on the second fixing plate section (23).

11. The ultra-high voltage converter station according to claim 10, characterized in that, The angle between the first fixed plate segment (21) and the middle plate segment (22) and the angle between the second fixed plate segment (23) and the middle plate segment (22) are both greater than or equal to 90°.

12. The ultra-high voltage converter station according to any one of claims 9 to 11, characterized in that, The clamp body includes two half clamps (11), and two fixing plates (14) are provided, with the two fixing plates (14) respectively located in the middle of the two half clamps (11).

13. The ultra-high voltage converter station according to any one of claims 9 to 11, characterized in that, The metal plating is silver plating.

14. The ultra-high voltage converter station according to any one of claims 9 to 11, characterized in that, Each aluminum terminal block (16) corresponds to at least two spaced aluminum pressure blocks (18).

15. The ultra-high voltage converter station according to any one of claims 9 to 11, characterized in that, Both the aluminum pressure block (18) and the aluminum terminal block (16) are provided with countersunk holes.

16. The ultra-high voltage converter station according to any one of claims 9 to 11, characterized in that, The aluminum pressure block (18) is provided with a first half groove (19), and the aluminum terminal block (16) is provided with a second half groove (20). The first half groove (19) and the second half groove (20) form a fixing groove for fixing the split wires; the groove walls of the first half groove (19) and / or the second half groove (20) are provided with cutting tool marks.

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