1100kV epoxy resin impregnated paper capacitive bushing for converter transformer network side

Abstract

The utility model provides a 1100kV epoxy resin impregnated paper capacitive bushing for a converter transformer network side, which comprises a capacitor core body and a bushing assembly, and the capacitor core body comprises a conductive tube, a capacitor core, a pull rod assembly, a current-carrying terminal assembly and a current-carrying contact finger. Wherein the current-carrying terminal assembly comprises a diversion column and a current-carrying table fixed at one end of the diversion column, the diversion column is located in a conductive tube, the current-carrying table blocks the end part of the conductive tube, a plurality of limiting structures are arranged in the axial direction of the diversion column at intervals, and the plurality of current-carrying contact fingers sleeve the diversion column and are in one-to-one correspondence with the plurality of limiting structures respectively. When the current-carrying terminal assembly is inserted and installed on the conductive tube, the limiting structure of the current-carrying column is in axial limiting fit with the current-carrying contact finger and drives the current-carrying contact finger to move into the conductive tube to be in conductive contact with the inner wall of the conductive tube, so that a plurality of current-carrying contact fingers are prevented from axially sliding, stacking and concentrating on the conductive column in the installation process; and good contact quality and current-carrying stability between the current-carrying terminal assembly and the conductive tube are ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of high-voltage power auxiliary equipment, and specifically provides an 1100kV epoxy resin impregnated paper capacitor bushing for a converter transformer grid side. Background Art

[0002] At present, the bushings on the converter transformer grid side of the converter station all use oil-impregnated paper capacitor bushing technology. At present, the current-carrying tubes of the 1100kV epoxy resin impregnated paper capacitor bushings on the converter transformer grid side mainly adopt the conventional structure with positioning tubes and conductive tubes.

[0003] The conventional structure has a complex installation structure. Especially in high-voltage application scenarios, the paper-impregnated capacitor bushing is prone to shunt discharge problems when installed offset or subjected to operating vibration. For example, discharge occurs between the current-carrying terminal and the positioning oil sealing tube, and between the positioning compensation tube and the conductive tube, affecting the current-carrying stability of the paper-impregnated capacitor bushing. It is also very likely to cause serious explosion accidents, threatening personal and property safety, and seriously affecting the safe and stable operation of cross-regional DC. This greatly restricts the application and development of oil-impregnated paper capacitor bushings in high-voltage application scenarios.

[0004] Accordingly, the art requires a new 1100kV epoxy resin impregnated paper capacitor bushing for use on the converter transformer grid side to solve the above problems. Utility Model Content

[0005] The utility model aims to solve the problem of poor current carrying stability of the existing 1100kV epoxy resin impregnated paper capacitor bushing used on the commutation transformer grid side.

[0006] The purpose of this utility model is to adopt the following technical solutions to achieve:

[0007] The utility model provides an 1100kV epoxy resin impregnated paper capacitor bushing for the converter transformer grid side, comprising a capacitor core and a bushing assembly sleeved on one side of the capacitor core, wherein the capacitor core comprises: a conductive tube; a capacitor core sleeved on the outside of the conductive tube; a pull rod assembly, one end of which is fixed in the conductive tube; a current-carrying terminal assembly mounted at the end of the conductive tube, the current-carrying terminal assembly comprising a coaxially arranged current guide column and a current-carrying platform fixed at one end of the current guide column, the current guide column being located in the conductive tube, and the current carrying terminal assembly comprising a coaxially arranged current guide column and a current-carrying platform fixed at one end of the current guide column. The current-carrying platform blocks the end of the conductive tube, the other end of the guide column is fixedly connected to the other end of the pull rod assembly, and a plurality of limiting structures are arranged at intervals in the axial direction of the guide column; and a plurality of current-carrying contact fingers are sleeved on the guide column and correspond one-to-one to the plurality of limiting structures respectively; when the current-carrying terminal assembly is plugged and installed on the conductive tube, the limiting structure of the guide column cooperates with the axial limiting of the current-carrying contact finger and drives the current-carrying contact finger to move into the conductive tube and make conductive contact with the inner wall of the conductive tube.

[0008] Preferably, the limiting structure includes an annular groove or a protrusion formed on the guide column, and the current-carrying contact finger is located in the annular groove or the current-carrying contact finger is located between two adjacent protrusions.

[0009] Preferably, an annular positioning groove is provided on the current-carrying platform, and the annular positioning groove is plug-fitted with the end portion of the conductive tube.

[0010] Preferably, a plurality of insulating spacers are provided between the conductive tube and the capacitor core, and the plurality of insulating spacers are distributed at intervals along the axial direction of the conductive tube.

[0011] Preferably, the bushing assembly includes a cover plate, an outer insulating bushing and a flange tube which are sealed and connected in sequence, the flange tube is sleeved on the capacitor core, and the conductive tube passes through the cover plate and is sealed and connected to the cover plate.

[0012] Preferably, the sleeve assembly is further provided with a first pressure equalizing ring, and the first pressure equalizing ring is installed on the cover plate.

[0013] Preferably, the sleeve assembly is further provided with a second pressure equalizing ring, and the second pressure equalizing ring is installed on the flange cylinder.

[0014] Preferably, the pull rod assembly includes a tensioning adjustment member, a first pull rod, a connecting member and a second pull rod that are fixedly connected in sequence, the tensioning adjustment member is fixed on the inner wall of the conductive tube, and the second pull rod is fixedly connected to the guide column.

[0015] Preferably, the flange tube is provided with measurement terminals for measuring the dielectric loss, partial discharge and capacitance of the capacitor core.

[0016] Preferably, the outer insulating sleeve is a silicone rubber composite sleeve or a porcelain sleeve.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] The utility model discloses an 1100kV epoxy resin impregnated paper capacitor bushing for use on the converter transformer grid side, comprising a capacitor core and a bushing assembly sleeved on one side of the capacitor core. The capacitor core comprises a conductive tube, a capacitor core, a pull rod assembly, a current-carrying terminal assembly, and a current-carrying contact finger. The capacitor core is sleeved on the outside of the conductive tube; one end of the pull rod assembly is fixed inside the conductive tube; the current-carrying terminal assembly is mounted on the end of the conductive tube. The current-carrying terminal assembly comprises a coaxially arranged current guide column and a current-carrying platform fixed to one end of the current guide column. The current guide column is located inside the conductive tube, and the current-carrying platform seals the end of the conductive tube. The other end of the current guide column is fixedly connected to the other end of the pull rod assembly. Multiple limiting structures are spaced apart axially along the guide column, and multiple current-carrying contact fingers are sleeved on the guide column and correspond one-to-one to the multiple limiting structures. Through such a setting, when the current-carrying terminal assembly is plugged into and installed on the conductive tube, the limiting structure of the guide column cooperates with the axial limiting of the current-carrying contact finger and drives the current-carrying contact finger to move into the conductive tube and make conductive contact with the inner wall of the conductive tube, thereby avoiding the axial sliding and stacking of multiple current-carrying contact fingers on the conductive column during the installation process, ensuring good contact quality between the current-carrying terminal assembly and the conductive tube, and improving the current-carrying stability and assembly efficiency of the 1100kV epoxy resin impregnated paper capacitor bushing used on the converter transformer grid side.

[0019] In addition, the internal structure of the 1100kV epoxy resin impregnated paper capacitor bushing for the converter transformer grid side of the present invention is simple. There is no multi-layer conduit structure inside the capacitor core, and it only contains a single current-carrying conduit, which effectively avoids the internal discharge problem between the positioning tube and the conductive tube of the traditional paper impregnated capacitor bushing under high-voltage working environment, and improves the use safety and current-carrying stability of the 1100kV epoxy resin impregnated paper capacitor bushing for the converter transformer grid side. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is an overall schematic diagram of the 1100kV epoxy resin impregnated paper capacitor bushing used on the grid side of the commutation transformer of the present invention;

[0021] Figure 2 This is a schematic cross-sectional view of the 1100kV epoxy resin impregnated paper capacitor bushing used on the commutation transformer grid side of the utility model;

[0022] Figure 3 for Figure 2 A is a partial enlarged schematic diagram of the preferred embodiment 1;

[0023] Figure 4 for Figure 2 A is a partially enlarged schematic diagram of the preferred embodiment 2.

[0024] Figure markings: 1-capacitor core; 11-current-carrying terminal assembly; 11a-current-guiding column; 11a1-protrusion; 11a2-annular groove; 11b-current-carrying platform; 11b1-annular positioning groove; 12-capacitor core; 13-conductive tube; 14-insulating isolation piece; 15-pull rod assembly; 151-first pull rod; 152-second pull rod; 153-connecting piece; 154-tensioning adjustment piece; 2-flange cylinder; 21-measuring terminal; 3-outer insulating sleeve; 31-sealed chamber; 41-first equalizing ring; 42-second equalizing ring; 5-cover plate; 6-current-carrying top sleeve; 7-current-carrying spring contact; 8-current-carrying contact finger. DETAILED DESCRIPTION

[0025] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0026] It should be noted that in the description of this utility model, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the device or element described must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, it should not be understood as limiting the utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance.

[0027] like Figures 1 to 3 As shown, the 1100kV epoxy resin-impregnated paper capacitor bushing for the grid side of the converter transformer of the present invention comprises a capacitor core 1 and a bushing assembly sleeved over one side of the capacitor core 1. The capacitor core 1 comprises a conductive tube 13, a capacitor core 12, a tie rod assembly 15, a current-carrying terminal assembly 11, and current-carrying contact fingers 8. The conductive tube 13, capacitor core 12, and bushing assembly are coaxially arranged from the inside out.

[0028] Specifically, if Figure 2 As shown, the capacitor core 12 in the present invention is sleeved on the outside of the conductive tube 13, and a plurality of insulating spacers 14 are provided between the conductive tube 13 and the capacitor core 12. The plurality of insulating spacers 14 are distributed at intervals along the axial direction of the conductive tube 13. The insulating spacers 14 are plug-in structures made of any one of insulating paper, epoxy resin or polytetrafluoroethylene solid materials, and the capacitor core 12 is made of epoxy resin glue-impregnated paper.

[0029] The upper region of the capacitor core 12 is encapsulated within the sealed chamber 31 of the bushing assembly, the lower region of the capacitor core 12 and the current-carrying terminal assembly 11 are both located outside the bushing assembly, the current-carrying terminal assembly 11 is mounted at the lower end of the conductive tube 13, and the upper end of the tie rod assembly 15 is fixed within the conductive tube 13. The tie rod assembly 15 comprises a tensioning adjustment member 154, a first tie rod 151, a connector 153, and a second tie rod 152, which are fixedly connected in sequence. The tensioning adjustment member 154 is fixed to the inner wall of the upper end of the conductive tube 13. By adjusting the tensioning adjustment member 154 to axially tighten the first tie rod 151, the connector 153, and the second tie rod 152, the current-carrying terminal assembly 11 is fixed to the lower end of the conductive tube 13. The tensioning adjustment member 154 can use a spring member to adjust the tensioning force.

[0030] Continue reading Figure 2 、 Figure 3 as well as Figure 4 The current-carrying terminal assembly 11 of the present invention includes a coaxially arranged guide column 11a and a current-carrying platform 11b fixed to the lower end of the guide column 11a. The guide column 11a is entirely located in the conductive tube 13. The upper portion of the current-carrying platform 11b blocks the lower end of the conductive tube 13. The upper end surface of the current-carrying platform 11b is provided with an annular positioning groove 11b1. The annular positioning groove 11b1 is plugged into and matched with the end of the conductive tube 13 so that the conductive column and the conductive tube 13 are coaxially arranged, ensuring radial stability between the conductive tube 13 and the current-carrying platform 11b, and ensuring that the guide column 11a is located on the central axis of the conductive tube 13 to ensure the uniformity of the electric field formed by the current passing through the guide column 11a. The upper end of the guide column 11a is fixedly connected to the lower end of the second pull rod 152. A plurality of limiting structures are arranged axially on the guide column 11a at intervals. A plurality of current-carrying contact fingers 8 are mounted and sleeved on the guide column 11a and correspond one-to-one to the plurality of limiting structures.

[0031] In a preferred embodiment, the limiting structure of the present invention includes a protrusion 11a1 formed on the guide column 11a, and the current-carrying contact finger 8 is located between two adjacent protrusions 11a1. Figure 3 As shown, three groups of protrusions 11a1 are spaced apart in the axial direction of the guide column 11a, and three current-carrying contact fingers 8 are respectively installed between the three groups of protrusions 11a1 and the end surface of the current-carrying platform 11b. Each group of protrusions 11a1 can be a plurality of protrusions distributed along the circumference of the guide column 11a, or a single annular protrusion.

[0032] In another preferred embodiment, the limiting structure of the present invention includes an annular groove 11a2 formed on the guide column 11a, and the current-carrying contact finger 8 is located in the annular groove 11a2. Figure 4 As shown, three annular grooves 11 a 2 are spaced apart in the axial direction of the current guide column 11 a , and a current-carrying contact finger 8 is installed in each annular groove 11 a 2 .

[0033] When the current-carrying terminal assembly 11 is plugged into and installed on the conductive tube 13, that is, when the guide column 11a is inserted into the conductive tube 13, the limiting structure on the guide column 11a cooperates with the axial limiting structure of the current-carrying contact finger 8 and drives the current-carrying contact finger 8 to move axially into the conductive tube 13 and make conductive contact with the inner wall of the conductive tube 13, thereby preventing the current-carrying contact finger 8 from sliding under force on the guide column 11a, resulting in axial concentrated stacking of multiple current-carrying contact fingers 8, ensuring that the current-carrying contact fingers 8 can be evenly distributed between the inner wall of the conductive tube 13 and the outer wall of the guide column 11a, thereby improving the current-carrying quality between the current-carrying terminal assembly 11 and the conductive tube 13, and the current-carrying terminal assembly 11 adopts a plug-in structure, which reduces the difficulty of on-site installation and improves installation efficiency.

[0034] It is understood that those skilled in the art, based on actual applications, will determine that, during operation, a portion of the current is diverted through the guide post 11a and the current-carrying contact fingers 8 to the inner wall of the conductive tube 13 for conduction, while a portion of the current is conducted through the end surface of the current-carrying platform 11b and the end surface of the guide post 11a, thereby preventing excessive local current from causing thermal expansion and contraction, which could affect the overall current-carrying stability of the bushing. Therefore, by extending the length of the guide post 11a and increasing the number of current-carrying contact fingers 8, the contact area between the extended conductive tube 13 and the current-carrying terminal assembly 11 is adjusted to facilitate current diversion and conduction.

[0035] like Figure 2 As shown, the bushing assembly of the present invention includes a cover plate 5, an outer insulating bushing 3, and a flange tube 2, which are sealed together in sequence. The flange tube 2 is sleeved onto the capacitor core 12, and the conductive tube 13 passes through the cover plate 5 and is sealed to the cover plate 5. An air-end current-carrying top sleeve 6 is mounted on the upper end of the conductive tube 13. The current-carrying top sleeve 6 is sleeved onto the upper end of the conductive tube 13. A plurality of current-carrying spring contacts 7 are fixed between the inner wall of the current-carrying top sleeve 6 and the outer wall of the conductive tube 13. A sealed chamber 31 is formed between the outer insulating bushing 3 and the capacitor core 12, and the sealed chamber 31 is filled with SF6 gas, an insulating medium. The bushing assembly also includes a first grading ring 41 and a second grading ring 42. The first grading ring 41 is mounted on the cover plate 5, and the second grading ring 42 is mounted on the flange tube 2. The flange tube 2 is equipped with measurement terminals 21 for measuring the dielectric loss, partial discharge, and capacitance of the capacitor core 12. The outer insulating bushing 3 is a silicone rubber composite bushing or a porcelain bushing.

[0036] It should be noted that a first grading ring 41 and a second grading ring 42 are arranged at the cover plate 5 and the flange tube 2 of the 1100kV epoxy resin impregnated paper capacitor bushing on the converter transformer side to form a double grading ring structure. The spatial capacitance formed by the structure and the bushing body capacitance work together to better uniformize the electric field, protect the bushing body, and improve the service life of the bushing, thereby avoiding uneven bushing field strength and excessive local field strength caused by the concentration of ultra-high voltage electric field.

[0037] In addition, the second grading ring 42 is located in the flange tube 2 area, which is beneficial to heat dissipation in the middle area of ​​the bushing, can shield the tips formed by the transformer raised box cover and cables, and avoid local discharge of the bushing.

[0038] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. An 1100kV epoxy resin impregnated paper capacitor bushing for use on the converter transformer grid side, comprising a capacitor core and a bushing assembly sleeved on one side of the capacitor core, characterized in that: The capacitor core comprises: Conductive tube; A capacitor core is sleeved on the outside of the conductive tube; a pull rod assembly, one end of which is fixed in the conductive tube; a current-carrying terminal assembly mounted at the end of the conductive tube, the current-carrying terminal assembly comprising a coaxially arranged current-carrying column and a current-carrying platform fixed to one end of the current-carrying column; the current-carrying column being located within the conductive tube, the current-carrying platform sealing the end of the conductive tube; the other end of the current-carrying column being fixedly connected to the other end of the pull rod assembly; and a plurality of limiting structures being spaced apart axially along the current-carrying column; and a plurality of current-carrying contact fingers, which are sleeved on the current guide column and correspond one-to-one to the plurality of limiting structures respectively; When the current-carrying terminal assembly is plugged and installed on the conductive tube, the limiting structure of the guide column cooperates with the axial limiting structure of the current-carrying contact finger and drives the current-carrying contact finger to move into the conductive tube and make conductive contact with the inner wall of the conductive tube.

2. The 1100kV epoxy resin impregnated paper capacitor bushing for the converter transformer grid side according to claim 1, characterized in that: The limiting structure includes an annular groove or a protrusion formed on the guide column, and the current-carrying contact finger is located in the annular groove or the current-carrying contact finger is located between two adjacent protrusions.

3. The 1100kV epoxy resin impregnated paper capacitor bushing for the converter transformer grid side according to claim 1, characterized in that: The current-carrying platform is provided with an annular positioning groove, and the annular positioning groove is plug-fitted with the end portion of the conductive tube.

4. The 1100kV epoxy resin impregnated paper capacitor bushing for the converter transformer grid side according to claim 1, characterized in that: A plurality of insulating spacers are provided between the conductive tube and the capacitor core, and the plurality of insulating spacers are distributed at intervals along the axial direction of the conductive tube.

5. The 1100kV epoxy resin impregnated paper capacitor bushing for the converter transformer grid side according to claim 1, characterized in that: The bushing assembly includes a cover plate, an outer insulating bushing and a flange tube which are sealed and connected in sequence. The flange tube is sleeved on the capacitor core. The conductive tube passes through the cover plate and is sealed and connected to the cover plate.

6. The 1100kV epoxy resin impregnated paper capacitor bushing for the converter transformer grid side according to claim 5, characterized in that: The sleeve assembly is further provided with a first pressure equalizing ring, which is mounted on the cover plate.

7. The 1100kV epoxy resin impregnated paper capacitor bushing for the converter transformer grid side according to claim 5, characterized in that: The sleeve assembly is further provided with a second pressure equalizing ring, which is mounted on the flange cylinder.

8. The 1100kV epoxy resin impregnated paper capacitor bushing for the converter transformer grid side according to claim 1, characterized in that: The pull rod assembly includes a tension adjustment member, a first pull rod, a connector and a second pull rod that are fixedly connected in sequence. The tension adjustment member is fixed on the inner wall of the conductive tube, and the second pull rod is fixedly connected to the guide column.

9. The 1100kV epoxy resin impregnated paper capacitor bushing for the converter transformer grid side according to claim 5, characterized in that: The flange tube is provided with measuring terminals for measuring dielectric loss, partial discharge and capacitance of the capacitor core.

10. The 1100kV epoxy resin impregnated paper capacitor bushing for the converter transformer grid side according to claim 5, characterized in that: The outer insulating sleeve is a silicone rubber composite sleeve or a porcelain sleeve.

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