Extra-high voltage composite phase-to-phase spacer

Abstract

The invention provides an extra-high voltage composite phase-to-phase spacer, and belongs to the technical field of extra-high voltage power transmission. The invention relates to an extra-high voltage composite phase-to-phase spacer. Two ends of a phase-to-phase composite insulator string are detachably and movably connected with a sub-conductor spacer through connecting fittings in a limiting manner; the interphase composite insulator string comprises three sections of insulators which are connected in sequence, and the insulators are detachably and movably connected through connecting fittings in a limiting manner; umbrella skirt sheaths are arranged at the two ends of the insulator in the middle, and the insulators on the two sides are of a full umbrella skirt sheath structure; voltage equalizing devices are arranged at two ends of the insulator; and the three sections of insulators are arranged in an equipotential manner. According to the spacer, the angle is easier to adjust due to the multi-section segmented design, so that different tower distances or topographic fluctuations can be matched; the voltage-sharing device further effectively reduces electric field distortion at the joint of the two ends of the insulator and the hardware fitting, the equipotential line can effectively prevent suspension potential and potential difference caused by poor contact when the connecting hardware fitting swings, and partial discharge and corona loss are further avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of UHV power transmission, and particularly relates to a UHV composite phase - interval rod. Background Art

[0002] With the rapid development of the global energy Internet, UHV power transmission projects are gradually extending to areas with complex terrains and harsh climates. In mountainous areas, cross - river corridors and multi - split conductor application scenarios, higher requirements are put forward for the mechanical properties, dynamic adaptability and engineering economy of phase - interval rods, and traditional designs face more challenges. In steep mountainous areas such as plateaus and mountains, as well as in large - span cross - river projects, transmission lines need to frequently cross deep valleys and rivers, resulting in significant differences in the distances between adjacent iron towers (ranging from 300m to 1500m, for example).

[0003] Traditional rigid phase - interval rods have two major problems due to their fixed length and limited adjustment ability: Fixed - length interval rods need to be customized for different tower distances, resulting in a complex supply chain, a sharp increase in costs, and insufficient terrain adaptability. In continuous spans with large sag differences, the rigid structure is prone to local stress concentration due to uneven wire tensions, accelerating metal fatigue. In addition, the strong turbulent wind field in mountain valleys is likely to induce high - frequency vibration of wires, and rigid interval rods cannot dissipate energy through deformation, resulting in the failure of dynamic wind vibration suppression, leading to excessive amplitudes of micro - vibration of wires and increasing the risk of aluminum strand breakage. Although rigid interval rods can limit the relative displacement of wires, excessive restraint will exacerbate the concentrated transfer of galloping energy to connection points, leading to structural failure; while traditional flexible interval rods are difficult to balance the asymmetric movement of multi - split conductors, resulting in unbalanced tensions of sub - conductors. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a UHV composite phase - interval rod in view of the insufficient terrain adaptability of the existing phase - interval rod.

[0005] To solve the above - mentioned technical problem, the technical solution adopted by the present invention is as follows:

[0006] A UHV composite phase - interval rod, characterized in that it includes a sub - conductor interval rod, an inter - phase composite insulator string, and a voltage - equalizing device; both ends of the inter - phase composite insulator string are detachably and limit - movably connected to the sub - conductor interval rod through connection fittings; the inter - phase composite insulator string includes three sequentially connected insulators, and the insulators are detachably and limit - movably connected through connection fittings; umbrella skirt sheaths are provided at both ends of the middle insulator, and the middle part is a structure of a core rod with an outer sheath; both side insulators are full - umbrella skirt sheath structures; voltage - equalizing devices are provided at both ends of the insulators; the connection points of the three insulator fittings are set to be equipotential.

[0007] Further, the insulator includes insulator fittings, a core rod, and an umbrella skirt sheath; one end of the core rod is externally nested and fixedly connected with one end of the insulator fittings, and the other end of the insulator fittings is an annular connection end; the annular connection end is sleeved with a U-shaped fitting ring; the U-shaped fitting rings are all fixedly connected to a fitting connection block through bolts.

[0008] Further, the maze-type multi-sealing structure at the nested end of the umbrella skirt sheath and the insulator fittings is integrally injection-molded; a groove is designed on the end face of the nested end of the insulator fittings; a convex block higher than the outer diameter plane is arranged on the outer side surface of the whole end of the insulator fittings, and a groove is also designed on the surface of the convex block; a wavy sealing groove is arranged on the side surface of the inner hole of the end of the insulator fittings.

[0009] Further, the spacer for sub-conductors includes a spacer frame body, a support plate, and spacer fittings; the support plate is a spoke-wheel type structure, and 8 protruding supports on the outside are bolted and fixedly connected to corresponding connection holes on the spacer frame body; one end of the spacer fittings is integrally fixedly connected to one of the protruding supports of the support plate.

[0010] Further, the spacer fittings are bolted and fixedly connected to the U-shaped fitting rings at both ends of the overall phase composite insulator.

[0011] Preferably, an aluminum cushion tube is provided when the spacer frame body is bolted and fixedly connected to the support plate and the spacer fittings, and the bolt is designed with a flat spring washer double-nut plus pin hole anti-loosening structure.

[0012] Further, the voltage equalizing devices at both ends of the phase composite insulator string each include a small voltage equalizing ring and a large voltage equalizing ring, and the other voltage equalizing devices are all medium voltage equalizing rings; the small voltage equalizing ring and the large voltage equalizing ring are relatively fixedly arranged in sequence at the end of the insulator close to the spacer for sub-conductors.

[0013] Further, the U-shaped fitting ring at one end of the overall phase composite insulator is bolted and fixedly connected to the spacer fittings, and an adjusting plate is bolted and fixedly connected between the U-shaped fitting ring at the other end and the spacer fittings.

[0014] Further, the adjusting plate includes a cross single plate and a one-word double plate with multiple bolt holes designed; the cross single plate is inserted along the length direction of the one-word double plate and is bolted and fixedly connected through at least three groups of bolt holes; the end of the cross single plate away from the one-word double plate is bolted and fixedly connected to the U-shaped fitting ring; the end of the one-word double plate away from the cross single plate is bolted and fixedly connected to the spacer fittings.

[0015] Preferably, an anti-corona voltage equalizing ring is fixedly sleeved on the outside of the cross single plate, the axis of the anti-corona voltage equalizing ring is parallel to the one-word double plate, and the anti-corona voltage equalizing ring is also sleeved on the outside of the vertical single plate of the cross single plate.

[0016] Compared with the prior art, the six-section segmented design of the spacer dampers of the present invention is easier to adjust the length and angle, so as to match different tower spacings, conductor phase spacings or terrain undulations; the annular connection end of the insulator fitting and the U-shaped fitting ring can be detachably and limitably disengaged from the ring connection, and the design and connection of the multi-section sleeve rings disperse the mechanical load and can absorb the energy of conductor dancing; the grading device further effectively reduces the electric field distortion at both ends of the insulator and the connection of the fitting, and the equipotential line can effectively prevent poor contact during the dancing of the connection fitting, resulting in floating potential and potential difference, further avoiding partial discharge and corona loss; a balance between reducing wind vibration and the stress on the core rod, and preventing dancing and corona is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] Figure 1 : Structural schematic diagram of Embodiment 1 of the present invention;

[0019] Figure 2 : Structural schematic diagram of the labyrinth multi-seal structure of the present invention;

[0020] Figure 3 : Structural schematic diagram of the layered connection structure of the support plate and the spacer damper frame of the present invention;

[0021] Figure 4 : Structural schematic diagram at the sub-conductor spacer damper of the present invention;

[0022] Figure 5 : Structural schematic diagram of Embodiment 2 of the present invention;

[0023] Wherein, 1 - sub-conductor spacer damper, 11 - spacer damper frame, 12 - support plate, 13 - spacer damper fitting, 14 - aluminum pad tube, 15 - connection hole, 2 - phase composite insulator string, 21 - insulator fitting, 22 - core rod, 23 - umbrella skirt sheath, 24 - annular connection end, 25 - U-shaped fitting ring, 26 - fitting connection block, 27 - insulator, 3 - grading device, 31 - large grading ring, 32 - medium grading ring, 33 - small grading ring, 4 - equipotential line, 5 - labyrinth multi-seal structure, 51 - groove, 52 - convex block, 53 - seal groove, 6 - adjustment plate, 61 - cross single plate, 62 - one-word double plate, 63 - anti-corona grading ring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] To better understand the present invention, the content of the present invention will be further clearly elaborated below in conjunction with embodiments. However, the protected content of the present invention is not limited to the following embodiments. In the following description, a large number of specific details are given to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details.

[0025] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components described in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that for the convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the said technologies, methods, and devices should be regarded as part of the authorized specification.

[0026] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom", etc. are usually based on the orientation or positional relationships shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description. Without contrary explanations, these orientation words do not indicate and imply that the devices or elements referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the protection scope of the present invention;

[0027] Embodiment 1, refer to Figures 1-3 ,

[0028] A UHV composite phase - interval rod, comprising a sub - conductor spacer 1, an inter - phase composite insulator string 2, and a voltage - equalizing device 3; both ends of the inter - phase composite insulator string 2 are connected to the sub - conductor spacer 1; the inter - phase composite insulator string 2 includes three sequentially connected insulators 27, and the insulators 27 are detachably and limit - movably connected through connecting fittings; umbrella skirt sheaths 23 are provided at both ends of the middle insulator 27, and the middle part is a structure of an outer - attached sheath on the core rod, and the insulators 27 on both sides are full - umbrella skirt structures; voltage - equalizing devices 3 are provided at both ends of the insulator 27; equipotential lines 4 are arranged in parallel at the joints of the fittings of the three insulators 27.

[0029] Furthermore, each of the insulators 27 includes an insulator fitting 21, a core rod 22, and an umbrella skirt sheath 23; one end of the core rod 22 is externally nested and fixedly connected to one end of the insulator fitting 21, and the other end of the insulator fitting 21 is an annular connection end 24; a U - shaped fitting ring 25 is sleeved on each of the annular connection ends 24; adjacent U - shaped fitting rings 25 are jointly fixed on a fitting connection block 26 through bolts, thereby forming a double - ring connection structure.

[0030] The core rod of the intermediate insulator 27 of the present invention can be designed with a core rod sheath combination of different lengths according to different phase spacings, which is used to greatly adjust the phase spacing. The multi-section connection design of the present invention is easier to adjust the angle, so as to match different tower spacings or terrain undulations, reduce the on-site cutting or customization requirements. Moreover, when the spacer between phases operates under extrusion load, the annular connection end of the insulator fitting 21 and the U-shaped fitting ring 25 can be relatively limited in position and compressed to move. The design connection of the multi-section sleeve ring disperses the mechanical load, can absorb the wire swing energy, reduces the impact of wind vibration or galloping on the structure, reduces local stress concentration, and delays metal fatigue. However, the way of the movable limit ring connection at this time is prone to generate floating potential and corona. The insulator of the present invention has three sections, and an equipotential line 4 is arranged between the three sections. The labyrinth multi-sealing structure 5 arranged on each section can block the penetration of the internal air gap and prevent the formation of a surface discharge channel, which is particularly suitable for high-altitude and low-pressure environments. Moreover, the equipotential line 4 cooperates with the voltage equalizing device 3 to further effectively reduce the electric field distortion at both ends of the insulator 27 and the connection part of the fitting, prevent partial discharge and corona loss, and achieve a balance of reducing stress, wind vibration, galloping prevention and corona prevention.

[0031] Further, the umbrella skirt sheath 23 is fixedly arranged on the peripheral side of the core rod 22; the labyrinth multi-sealing structure 5 at the nested end of the umbrella skirt sheath 23 and the insulator fitting 21 is fixedly connected; preferably, the umbrella skirt sheath 23 and the labyrinth multi-sealing structure 5 are integrally injection molded; a groove 51 is arranged on the end face of the nested end of the insulator fitting 21, and the width and depth of the groove 51 are not less than 2 mm; a convex block 52 is arranged on the outer side surface of the peripheral part of the end of the insulator fitting 21, the height of the convex block 52 is 2-4 mm higher than the outer diameter plane, and the width is 6-10 mm. The surface of the convex block 52 is also provided with a groove 51, and the width and depth of the groove 51 are also not less than 2 mm; a wavy sealing groove 53 is arranged on the side part of the inner hole of the end of the insulator fitting 21, the depth of the sealing groove 53 is 6-8 mm, and the diameter is 2-4 mm larger than the inner hole. The labyrinth design is composed of mutually nested sealing grooves 53, convex blocks 52, grooves 51 or wavy structures, forming multiple checkpoints. Moisture, salt spray or pollutants need to break through multiple sealing interfaces in turn to invade the interior, greatly prolonging the penetration time and improving its service life.

[0032] Preferably, the umbrella skirt sheath 23 all adopts a large-small-medium-small umbrella skirt structure. The large umbrella provides the main insulation barrier, and the medium and small umbrellas fill the weak electric field area to suppress partial discharge; the medium umbrella, as a transition structure, can relieve the sudden change of the electric field between the large and small umbrellas. The alternating umbrella shape increases the complexity of the arc development path, prolongs the creepage path, and improves the flashover voltage threshold. It can reduce the equivalent diameter of the composite insulator, and the umbrella skirt is designed as an aerodynamic umbrella skirt. The alternation of large and small umbrellas can form an uneven umbrella spacing, block the continuous accumulation of dirt, and reduce the probability of forming a path for the surface leakage current.

[0033] Furthermore, the sub-conductor spacer 1 includes a spacer frame 11, a support plate 12 and spacer fittings 13; the support plate 12 is in a spoke-wheel structure, and eight protruding fulcrums arranged on the outer side are fixedly connected to corresponding connection holes 15 on the spacer frame 11 by bolts; one end of the spacer fittings 13 is integrally and fixedly connected to one of the protruding fulcrums of the support plate 12.

[0034] Furthermore, the spacer fittings 13 are also fixedly connected to the U-shaped fitting rings 25 at both ends of the phase composite insulator string 2 by bolts, thereby forming a single-ring connection structure. An equipotential line 4 can also be arranged in parallel at the movable connection of the spacer fittings 13 and the fittings of the phase composite insulator string 2.

[0035] Furthermore, when the spacer frame 11 is fixedly connected to the support plate 12 and the spacer fittings 13 by bolts, an aluminum pad tube 14 is provided. The bolts are designed with a flat spring washer double-nut plus pin-hole anti-loosening structure. The spacer frame 11 and the support plate 12 are generally made of dissimilar metals, such as an aluminum spacer frame and a galvanized steel support plate. Direct contact between the two will form an electrochemical corrosion cell. The aluminum pad tube 14, as a same-material isolation layer, can cut off the direct corrosion of the corrosion current to the spacer frame, maintain the mechanical structure stability of the spacer frame, and reduce the rust risk of the spacer frame. Moreover, the spacer needs to bear dynamic forces such as conductor vibration and wind load in the transmission line. The aluminum pad tube 14, as an elastic medium, can absorb part of the vibration energy, reduce the rigid impact between the frame and the connecting plate, and reduce metal fatigue and structural damage.

[0036] Furthermore, the grading devices 3 at both ends of the phase composite insulator string 2 each include a small grading ring 33 and a large grading ring 31, and the rest of the grading devices 3 are all medium grading rings 32; the small grading ring 33 and the large grading ring 31 are sequentially and fixedly arranged at the end of the insulator 28 close to the sub-conductor spacer 1. Through electric field simulation calculation, the large grading ring 31 has a ring diameter of 1350 mm and a pipe diameter of 150 mm, the small grading ring 33 has a ring diameter of 350 mm and a pipe diameter of 40 mm, and the middle section adopts the design of the medium grading ring 32. The medium grading ring 32 has a ring diameter of 560 mm and a pipe diameter of 60 mm. After installing this grading ring, it can ensure that the electric field on the surface of the insulator is lower than 4.5 kV / cm, and the electric field on the surface of the grading ring is lower than 22 kV / cm.

[0037] The large grading ring 31 is mainly responsible for macroscopic electric field regulation to reduce the overall field strength peak value; the embedded small grading ring 33 focuses on local high-field strength regions, such as conductor connection points, insulator ends, etc. Through "secondary grading", the electric field gradient is further smoothed to avoid edge electric field distortion caused by insufficient coverage of the large ring. The electric field superposition of the large ring and the small ring can form a more gentle potential distribution. At the junction of the conductor and the insulator, the small ring can compensate for the sudden increase in field strength caused by the size limitation of the large ring and reduce the local field strength, thereby further effectively suppressing corona discharge.

[0038] Example 2. Refer to Figure 4 , this example is improved on the basis of Example 1.

[0039] Furthermore, the U-shaped fitting ring 25 at one end of the phase composite insulator string 2 is fixedly connected to the spacer fitting 13 by bolts, and an adjusting plate 6 is also fixedly connected between the U-shaped fitting ring 25 at the other end and the spacer fitting 13 by bolts. The bolts on the adjusting plate 6 are all corona-proof bolts.

[0040] Furthermore, the adjusting plate 6 includes a cross single plate 61 and a one-word double plate 62 both designed with multiple bolt holes; the cross single plate 61 is inserted along the length direction of the one-word double plate 62 and is fixedly connected by bolts through at least three groups of bolt holes; the end of the cross single plate 61 away from the one-word double plate 62 is fixedly connected to the U-shaped fitting ring 25 by bolts; the end of the one-word double plate 62 away from the cross single plate 61 is fixedly connected to the spacer fitting 13 by bolts. Both the one-word double plate 62 and the cross single plate 61 are designed with multiple holes, and the distance between the holes is not less than 50 mm. After the cross single plate 61 and the one-word double plate 62 are assembled, the length adjustment range is not less than 500 mm. It can be used to adjust the phenomenon that the phase spacing size does not conform due to measurement errors to ensure appropriate tension of the phase conductors, or to adjust the position of the conductors in complex terrains to adapt to different spans or terrain changes for convenient on-site installation.

[0041] To further prevent corona from occurring at the bolts and nuts, a corona-proof grading ring 63 is fixedly sleeved outside the cross single plate 61. The axis of the corona-proof grading ring 63 is parallel to the one-word double plate 62, and the corona-proof grading ring 63 is also sleeved outside the vertical single plate of the cross single plate 61. The size of this grading ring is calculated by electric field simulation, with a ring diameter of 900 mm and a pipe diameter of 80 mm. Compared with the traditional installation position of the grading ring at the top of the insulator string or the end of the connecting fitting, this corona-proof grading ring 63 reduces the need for independent brackets (the traditional grading ring requires additional installation of tower bodies or insulator string support brackets), and the adjusting plate in the shape of a cross after combination itself serves as a load-bearing component. Integrating the grading ring can eliminate the independent brackets, reduce the complexity of the tower head structure, and can also guide the uniform distribution of electric field lines through the porous structure of the adjusting plate.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Any other modifications or equivalent replacements made by those of ordinary skill in the art to the technical solutions of the present invention shall be covered within the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solutions of the present invention.

[0043] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A UHV composite phase - to - phase spacer, characterized in that: It includes sub-conductor spacer dampers, phase composite insulator strings, and voltage equalizing devices; both ends of the phase composite insulator strings are detachably and limitably movably connected to the sub-conductor spacer dampers through connecting fittings; the phase composite insulator strings include three insulators connected in sequence, and the insulators are detachably and limitably movably connected through connecting fittings; umbrella skirt sheaths are arranged at both ends of the middle insulator, and the middle part is a structure with a sheath attached to the core rod; the insulators on both sides are full-umbrella skirt sheath structures; voltage equalizing devices are arranged at both ends of the insulators; equipotential settings are made among the three insulators.

2. The UHV composite phase - interval rod according to claim 1, wherein: The insulator includes insulator fittings, a core rod, and an umbrella skirt sheath; one end of the core rod is externally nested and fixedly connected with one end of the insulator fittings, and the other end of the insulator fittings is an annular connection end; a U-shaped fitting ring is sleeved on the annular connection end; the U-shaped fitting rings are all fixedly connected to the fitting connection block through bolts together.

3. The UHV composite phase - interval rod according to claim 2, wherein: The umbrella skirt sheath is integrally injection-molded with the labyrinth multi-sealing structure at the nested end of the insulator fittings; a groove is designed on the end face of the nested end of the insulator fittings; a convex block higher than the outer diameter plane is arranged on the outer side surface of the whole end of the insulator fittings, and a groove is also designed on the surface of the convex block; a wavy sealing groove is arranged on the side surface of the inner hole at the end of the insulator fittings.

4. The UHV composite phase - interval rod according to claim 2, characterized in that: The sub-conductor spacer damper includes a spacer damper frame body, a support plate, and spacer damper fittings; the support plate is a spoke wheel structure, and 8 protruding supports on the outside are bolt-fixed to the corresponding connection holes on the spacer damper frame body; one end of the spacer damper fittings is integrally fixedly connected to one of the protruding supports of the support plate.

5. The UHV composite phase - interval rod according to claim 4, wherein: The spacer damper fittings are bolt-fixed to the U-shaped fitting rings at both ends of the whole phase composite insulator.

6. The UHV composite phase interval rod according to claim 4, characterized in that: When the spacer damper frame body is bolt-fixed to the support plate and the spacer damper fittings, an aluminum pad tube is padded, and the bolts are designed with a flat spring washer double-nut plus pin hole anti-loosening structure.

7. The UHV composite phase - interval rod according to claim 1, characterized in that: The voltage equalizing devices at both ends of the phase composite insulator strings both include a small voltage equalizing ring and a large voltage equalizing ring, and the rest of the voltage equalizing devices are all medium voltage equalizing rings; the small voltage equalizing ring and the large voltage equalizing ring are sequentially and relatively fixedly arranged at the end of the insulator close to the sub-conductor spacer damper.

8. The UHV composite phase - interval rod according to claim 4, characterized in that: The U-shaped fitting ring at one end of the whole phase composite insulator is bolt-fixed to the spacer damper fittings, and an adjusting plate is bolt-fixed between the U-shaped fitting ring at the other end and the spacer damper fittings.

9. The UHV composite phase - interval rod according to claim 8, wherein: The adjusting plate includes a cross single plate and a one-word double plate with multiple bolt holes designed; the cross single plate is inserted along the length direction of the one-word double plate and is bolt-fixed through at least three groups of bolt holes; the end of the cross single plate far from the one-word double plate is bolt-fixed to the U-shaped fitting ring; the end of the one-word double plate far from the cross single plate is bolt-fixed to the spacer damper fittings.

10. A UHV composite phase - interval rod according to claim 9, characterized in that: An anti-corona voltage equalizing ring is fixedly sleeved on the outside of the cross single plate, the axis of the anti-corona voltage equalizing ring is parallel to the one-word double plate, and the anti-corona voltage equalizing ring is also sleeved on the outside of the single plate in the vertical direction of the cross single plate.

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