Built-in grading ring and reactor

Abstract

The utility model relates to a kind of built-in voltage-sharing rings, including pipe body, ball head, support and central shaft;The central shaft is arranged in pipe body, with the length direction parallel of pipe body and is fixed with pipe body by support, one ball head is respectively arranged in the both ends of pipe body, gap is equipped between ball head and pipe body and is fixedly connected with central shaft.A kind of electric reactor, including star arm support and coil, coil is connected in star arm support inside, further include above-mentioned built-in voltage-sharing ring, several described built-in voltage-sharing rings are evenly arrayed along circumferential position and are arranged in the form of voltage-sharing ring group around the circumferential array of coil central shaft;The upper portion and the lower portion of the inner diameter of the coil are each provided with one voltage-sharing ring group;Gap is provided between the adjacent built-in voltage-sharing rings in the voltage-sharing ring group.The utility model connects to break the connection of ball head and pipe body to block current path, avoid eddy current to form larger eddy current loop by pipe body and ball head, in the case where the optimization effect of electric field is substantially unchanged, effectively reduce the hotspot temperature rise of voltage-sharing ring eddy current loss heating.

Description

Technical Field

[0001] This utility model belongs to the technical field of built-in equalizing ring and reactor, and particularly relates to a built-in equalizing ring and reactor. Background Technology

[0002] my country has a vast territory, and its energy resources and load centers are distributed in opposite directions. The western region is rich in clean energy sources such as wind and solar power, while the eastern region has concentrated electricity demand. Ultra-high voltage direct current (UHVDC) transmission has become the core technology for "West-to-East Power Transmission" due to its outstanding advantages such as low loss and flexible control in large-capacity, long-distance power transmission.

[0003] However, my country's terrain slopes from west to east, and the western energy bases are generally at high altitudes. Ultra-high-voltage direct current (UHVDC) transmission projects must face unique environmental challenges in high-altitude regions during long-distance power transmission to the east. Increased altitude leads to decreased air density and changes in relative humidity; these meteorological conditions significantly reduce the external insulation performance and corona induction field strength of electrical equipment. Major projects currently under construction, such as the Tibet-Guangdong UHVDC project, have their converter stations located in high-altitude areas, placing even more stringent requirements on the insulation design and voltage equalization shielding of critical equipment within the stations.

[0004] Dry-type air-core reactors are indispensable main equipment in DC transmission systems, performing functions such as filtering, current limiting, and power regulation. Their long-term stable operation directly affects system safety and power quality. With the continuous increase in DC system voltage levels, the electric field strength on the reactor surface, especially at the coil ends and metal fittings, increases significantly. In high-altitude environments, the air insulation strength decreases, further reducing the corona discharge field strength on the fitting surface, making corona discharge highly likely to occur at the upper and lower ends of the reactor. Sustained corona discharge not only causes aging of insulation materials and localized overheating but may also gradually develop into arc discharge or even insulation breakdown, seriously threatening the safe and stable operation of the entire transmission system.

[0005] Therefore, how to rationally design the equalizing shielding device for dry-type air-core reactors to effectively suppress corona generation and improve electric field distribution in the special environment of high altitude has become a key technical challenge in the design and construction of current ultra-high voltage direct current projects, and has important practical engineering significance for ensuring the long-term reliable operation of major power transmission projects. Utility Model Content

[0006] This invention provides a built-in equalizing ring and reactor to solve technical problems existing in prior art. It is particularly suitable for dry-type air-core reactors in high-altitude areas, enhancing the overall insulation resistance, especially the operational shock resistance between the upper and lower star-shaped coils. The unique structural design of the equalizing ring avoids excessive eddy current losses and temperature rise.

[0007] The present invention includes the following technical solution: a built-in equalizing ring, comprising a tube body, ball heads, a bracket and a central shaft; the central shaft is disposed inside the tube body, parallel to the length direction of the tube body and fixed to the tube body by the bracket, and a ball head is disposed at each end of the tube body, with a gap between the ball head and the tube body and fixedly connected to the central shaft.

[0008] Furthermore, the tube body is made of a curved thin-walled hollow circular tube, and the tube body has several openings parallel to the length direction of the tube body.

[0009] Furthermore, the opening is formed by uniformly arrayed slots along the circumference of the circular tube, with the slots extending from both ends toward the middle, and the middle section retaining a certain width without being fully penetrated, in order to maintain the integrity of the curved thin-walled hollow circular tube.

[0010] Furthermore, the edges of the grid structure formed at both ends after the round tube is cut are rounded.

[0011] Furthermore, the ball head is a hollow hemispherical structure with a screw structure welded inside, and the edges of the ball head are rounded.

[0012] Furthermore, the central shaft is a hollow circular tube with threaded holes at both ends, and the threads inside the threaded holes are connected to the screw structure inside the ball head.

[0013] Furthermore, the bracket is fixed to the part of the tube that is not open and penetrated.

[0014] Furthermore, the bracket is perpendicular to the central axis, and a groove conforming to the curvature of its outer surface is provided at the junction of the bracket and the central axis to facilitate fixing the central axis. A certain groove is made in the un-through section of the tube body. After the bracket is inserted, the contact area between the bracket and the tube body and the connection area between the bracket and the central axis are welded respectively.

[0015] A reactor includes a star-shaped support and a coil. The coil is connected to the inner side of the star-shaped support. It also includes the aforementioned built-in equalizing rings. A plurality of the built-in equalizing rings are arranged in a uniform array along the circumferential direction and are arranged in a circular array around the central axis of the coil to form an equalizing ring group. An equalizing ring group is provided at the upper and lower parts of the inner diameter of the coil. A gap is provided between adjacent built-in equalizing rings in the equalizing ring group to disperse the eddy current path in segments. The gaps allow multiple built-in equalizing rings to form a segmented equalizing ring group, thereby blocking the heat conduction path. A single segment failure does not affect the overall operation.

[0016] Furthermore, the reactor is also equipped with a rain cap on top, and an external equalizing ring is provided below the rain cap; the rain cap is a protective top structure to prevent rainwater and dust from entering the coil or the internal equalizing ring, ensuring long-term stable insulation performance, and is especially suitable for outdoor substations or new energy power plants and other environments.

[0017] The advantages and positive effects of this utility model are as follows: This invention blocks the current path by disconnecting the ball head from the tube body, thus preventing eddy currents from forming a large eddy current loop through the tube body and ball head. While ensuring that the optimization effect of the electric field between the coil and the star frame arm remains basically unchanged, it effectively reduces the temperature rise of the hot spot caused by the eddy current loss of the equalizing ring.

[0018] This utility model adopts a design with several strip-shaped openings on the tube body. The openings extend from both ends of the tube body towards the middle to block the current path on the tube body, while also further increasing the heat dissipation area. The edges at both ends of the tube body are chamfered to avoid distortion of the electric field at the ends.

[0019] This invention improves the insulation withstand capability of the reactor by adding built-in equalizing rings near the upper and lower star-shaped frames (i.e., the upper and lower parts of the coil); by adopting the built-in equalizing ring structure in this invention, the temperature rise of hot spots can be reduced by about 87% compared with ordinary equalizing ring structures. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural diagram of the built-in equalizing ring of this utility model; Figure 2 This is a cross-sectional view of the internal structure of the built-in equalizing ring of this utility model; Figure 3 This is a schematic diagram of the pipe body with a built-in equalizing ring; Figure 4 This is a schematic diagram of the structure of a ball head with a built-in equalizing ring; Figure 5 This is a schematic diagram of the layout of the built-in equalizing ring device in the reactor support system; In the diagram, 1. Built-in equalizing ring; 11. Ball head; 12. Tube body; 13. Central shaft; 14. Support; 15. Screw structure; 2. External equalizing ring; 3. Rain cap; 4. Star frame arm; 5. Coil. Detailed Implementation

[0021] To further disclose the invention content, features, and effects of this utility model, the following examples are provided in conjunction with the accompanying drawings for detailed description. In the following description of the embodiments, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this patent and simplifying the description. They do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this patent.

[0022] In the following description of the embodiments, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0023] Example 1: See Appendix Figure 1-4 An internal equalizing ring includes a tube body 12, a ball head 11, a bracket 14 and a central shaft 13; the central shaft 13 is disposed inside the tube body 12, parallel to the length direction of the tube body 12 and fixed to the tube body 12 by a bracket 14, and a ball head 11 is disposed at each end of the tube body 12, with a gap between the ball head 11 and the tube body 12 and fixedly connected to the central shaft 13.

[0024] like Figures 2-3 As shown, the tube 12 is made of a curved thin-walled hollow circular tube, and the tube 12 has several openings parallel to its length. These openings are formed by uniformly arrayed slots along the circumference of the circular tube, extending from both ends towards the center, with a certain width left unconnected in the center to maintain the integrity of the curved thin-walled hollow circular tube. The edges of the grid structures formed at both ends after the circular tube is cut are rounded.

[0025] The central shaft 13 is a hollow circular tube with a wall thickness of 5mm to reduce eddy current losses. It has threaded holes at both ends, with threads inside the holes connecting to the screw structure 15 inside the ball head 11. A bracket 14 is connected to the center of the central shaft 13, acting as a bridge to fix the tube body 12 and the central shaft 13 into a single unit. The bracket 14 is fixed to the unopened portion of the tube body 12. The bracket 14 is perpendicular to the central shaft 13, and a groove conforming to the curvature of its outer surface is provided at the junction of the bracket 14 and the central shaft 13 to facilitate fixing the central shaft 13. A groove is made in the unopened portion of the tube body 12, and after inserting the bracket 14, the contact area between the bracket 14 and the tube body 12, and the connection area between the bracket 14 and the central shaft 13 are welded.

[0026] like Figure 4 As shown, the ball head 11 is a hollow hemispherical structure with a wall thickness of 2mm. A screw structure 15 is welded to the center of the interior. The edge area of ​​the ball head 11 is rounded to avoid distortion of the electric field at the end. At the same time, the open structure increases the heat dissipation area, so that the heat can be better dissipated.

[0027] Example 2: See Appendix Figure 1-5A reactor includes a star-shaped support frame 4 and a coil 5. The coil 5 is connected to the inner side of the star-shaped support frame 4. The star-shaped support frame 4 is a mechanical support structure that fixes the built-in equalizing ring 1, the external equalizing ring 2, and the coil 5. Its star-shaped design disperses mechanical stress, improves seismic resistance and overall rigidity, and avoids electric field distortion caused by displacement. The reactor also includes the built-in equalizing ring 1 described in Embodiment 1. Several of the built-in equalizing rings 1 are evenly arranged in a circumferential array and are arranged in a circular array around the central axis of the coil 5 to form an equalizing ring group. An equalizing ring group is provided at the upper and lower parts of the inner diameter of the coil 5. A gap is provided between adjacent built-in equalizing rings 1 in the equalizing ring group to disperse the eddy current path in segments. The gaps allow multiple built-in equalizing rings 1 to form a segmented equalizing ring group, thereby blocking the heat conduction path. A single segment failure does not affect the overall operation.

[0028] like Figure 5 As shown, a rain cap 3 is also installed on the top of the reactor, and an external equalizing ring 2 is provided below the rain cap 3. The rain cap 3 is a protective top structure to prevent rainwater and dust from entering the coil 5 or the built-in equalizing ring 1, ensuring long-term stable insulation performance, and is especially suitable for outdoor substations or new energy power stations and other environments.

[0029] Working principle: The built-in equalizing ring 1 blocks the current path by disconnecting the ball head 11 from the tube body 12, preventing eddy currents from forming a large eddy current loop through the tube body 12 and the ball head 11. While ensuring that the optimization effect of the electric field between the coil 5 and the star frame arm 4 remains basically unchanged, it effectively reduces the temperature rise of the hot spot caused by eddy current loss of the equalizing ring. By installing the built-in equalizing ring 1 near the upper and lower star frame (i.e., the upper and lower parts of the coil 5), the insulation withstand capability of the reactor is improved. Using the built-in equalizing ring 1 structure in this utility model, the hot spot temperature rise can be reduced by about 87% compared with the ordinary equalizing ring structure.

[0030] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other modifications under the guidance of the present invention without departing from the spirit and scope of the claims. These modifications all fall within the protection scope of the present invention.

Claims

1. A built-in equalizing ring, characterized in that: It includes a tube body, ball heads, a support, and a central shaft; the central shaft is set inside the tube body, parallel to the length direction of the tube body, and fixed to the tube body by the support; a ball head is set at each end of the tube body, and there is a gap between the ball head and the tube body and it is fixedly connected to the central shaft.

2. The built-in equalizing ring according to claim 1, characterized in that: The tube is made of a curved, thin-walled hollow circular tube, and has several openings parallel to the length of the tube.

3. The built-in equalizing ring according to claim 2, characterized in that: The opening is formed by uniformly arrayed slots along the circumference of the circular tube, with the slots extending from both ends toward the middle, and the middle section retaining a certain width but not being completely through.

4. The built-in equalizing ring according to claim 3, characterized in that: The edges of the grid structure formed at both ends after the round tube is cut are all rounded.

5. The built-in equalizing ring according to claim 1, characterized in that: The ball head is a hollow hemispherical structure with a screw structure welded inside, and the edges of the ball head are rounded.

6. A built-in equalizing ring according to claim 5, characterized in that: The central shaft is a hollow circular tube with threaded holes at both ends. The threads inside the threaded holes are connected to the screw structure inside the ball head.

7. A built-in equalizing ring according to claim 3, characterized in that: The bracket is fixed to the middle part of the tube that is not open.

8. A built-in equalizing ring according to claim 7, characterized in that: The bracket is perpendicular to the central axis, and a groove that fits the curvature of its outer surface is provided at the junction of the bracket and the central axis.

9. A reactor, comprising a star-shaped support frame and a coil, wherein the coil is connected to the inner side of the star-shaped support frame, characterized in that: It also includes the built-in equalizing rings as described in any one of claims 1-8, wherein a plurality of the built-in equalizing rings are arranged in a uniform array along the circumferential position and are arranged in a circular array around the central axis of the coil to form an equalizing ring group; an equalizing ring group is provided at the upper part and the lower part of the inner diameter of the coil; and a gap is provided between adjacent built-in equalizing rings in the equalizing ring group.

10. A reactor according to claim 9, characterized in that: The reactor is also equipped with a rain cap on top, and an external equalizing ring is located below the rain cap.

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