Configuration method for vertically arranging wire tension string in extra-heavy ice area

Abstract

The invention relates to the technical field of extra-high voltage transmission line tension string arrangement, and particularly discloses a configuration method for vertically arranging a wire tension string in an extra-heavy ice area, which specifically comprises the following steps: S1, determining the mechanical strength of the tension string; s2, determining the number of links of the strain insulator string, wherein the number of links is at least six; s3, determining an arrangement type of the strain insulator string, wherein the arrangement type is vertical layered arrangement; s4, determining the number of hanging points of the strain insulator string, wherein the number of the hanging points is at least two groups; and S5, determining the optimal joint distance of the multi-joint strain insulator string by calculating the electrical distance, the offset distance and the deicing jump distance of the multi-joint strain insulator string. According to the utility model, the problem that the horizontal arrangement distance is too wide when a multi-split large-cross-section wire is used is effectively solved, the structural stress of an iron tower and a tension string is improved, the safety and stability of the tension string in an extra-heavy ice area are improved, and the structure takes into account the aesthetic property of a fitting string.

Description

Technical Field

[0001] The present invention relates to the technical field of arrangement of tension strings for ultra-high voltage transmission lines, and more particularly to a configuration method for vertically arranging conductor tension strings in extremely heavy ice areas. Background Art

[0002] With the rapid development of UHV transmission projects in my country, these projects have been extended to heavily icy areas. UHV transmission lines in these heavily icy areas often pass through high altitudes and areas with large elevation differences, making the terrain even more severe than before.

[0003] Due to factors such as transmission capacity, ice coverage, and the electromagnetic environment at high altitudes, multi-split, large-section conductors are typically used. The total cross-section of a single phase (pole) often exceeds 5000mm². The resulting longitudinal breaking force and load are excessive, necessitating the structural strength of a six-pair insulator. Conventional four-pair horizontal tension strings are insufficiently strong and unsuitable. However, due to the large number of six-pairs, if all six are arranged horizontally, the width of the tension string would be excessive, leading to problems with tower mounting point placement, string width, and uneven stress distribution. With the recent increase in UHV transmission lines, this phenomenon has become increasingly significant.

[0004] Therefore, an improved conductor tension string is needed to effectively solve the problems of excessively wide horizontal spacing and uneven structural stress when multiple split large-section conductors are used, improve the safety and stability of the tension string in extremely heavy ice areas, and take into account the aesthetics of the hardware string. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for configuring a vertically arranged conductor tension string in extremely heavy ice regions, effectively solving the problem of excessively wide horizontal spacing when multiple large-section conductors are split, improving the stress of the tower and tension string structure, and enhancing the safety and stability of the tension string in extremely heavy ice regions, while also taking into account the aesthetics of the hardware string structure.

[0006] The solution adopted by the present invention to solve the technical problem is:

[0007] A method for configuring a vertically arranged conductor tension string in an extremely heavy ice area specifically comprises the following steps:

[0008] Step S1: determining the mechanical strength of the tension string;

[0009] Step S2: determining the number of tension strings, wherein the number of strings is at least six;

[0010] Step S3: determining the arrangement type of the tension string, wherein the arrangement type is a vertical layered arrangement;

[0011] Step S4: determining the number of hanging points of the tension string, wherein the number of hanging points is at least two groups;

[0012] Step S5: Determine the optimal spacing of the multiple-unit tension strings by calculating the electrical distance, offset distance, and ice-shedding jump distance of the multiple-unit tension strings.

[0013] In some possible implementations, when the number of links is six, a two-layer vertical arrangement is adopted, with three links in each layer.

[0014] In some possible implementations, the optimal link distance includes an optimal link spacing in the horizontal direction and an optimal link spacing in the vertical direction.

[0015] In some possible implementations, the electrical distance of the multi-connected tension strings in step S5 is calculated as:

[0016] L1≥max(a,b);

[0017] Wherein, L1 represents the electrical distance of the multi-connected tension string;

[0018] a represents the minimum clear distance when multiple tension strings are connected in parallel and the discharge process can develop independently;

[0019] b represents the minimum clear space distance when multiple tension strings are connected in parallel and the pollution flashover voltage of a single tension string is the same.

[0020] In some possible implementations, the offset distance of the multiple tension strings in step S5 is calculated as:

[0021] L2≥fsin(atan(G4 / G1))+n;

[0022] Wherein, L2 represents the offset distance of the multi-connected tension string;

[0023] f represents the sag value of the multi-connected tension string under the approximate catenary line;

[0024] G4 represents the horizontal load of the multi-connected tension string under high wind conditions;

[0025] G1 represents the vertical load of the multi-connected tension string under high wind conditions;

[0026] n represents the maximum diameter of the insulator.

[0027] In some possible implementations, the ice-shedding jump distance of the multi-connected tension string in step S5 is calculated as:

[0028] L3≥max(c,d,e);

[0029] Among them, L3 represents the ice-shedding jump distance of the multi-connected tension string;

[0030] c represents the jump distance caused by the de-icing of the multi-connected tension string itself;

[0031] d represents the jump distance of the multi-connected tension string caused by the conductor ice shedding;

[0032] e represents the comprehensive jump distance of the multi-connected tension string caused by the simultaneous ice shedding of the string itself and the conductors.

[0033] In some possible implementations, the optimal vertical spacing of the multiple tension strings is:

[0034] H≥max(a,b);

[0035] H≥fi+n;

[0036] H≥max(c,d,e);

[0037] Wherein, H represents the vertical spacing of multiple tension strings;

[0038] a represents the minimum clear distance between multiple tension strings connected in parallel and able to develop independently during the discharge process;

[0039] b represents the minimum clear space distance when multiple tension strings are connected in parallel and the pollution flashover voltage of a single tension string is the same;

[0040] n represents the maximum diameter of the disc insulator;

[0041] c represents the jump distance caused by ice shedding of the tension string itself;

[0042] d represents the jump distance of the tension string caused by the conductor falling off the ice;

[0043] e represents the comprehensive jump distance caused by the simultaneous ice shedding of the tension string itself and the conductor;

[0044] fi represents the maximum sag value of the tension string under icing conditions.

[0045] In some possible implementations, the optimal horizontal spacing of the multi-link tension strings is:

[0046] L≥max(a,b);

[0047] L≥fsin(atan(G4 / G1))+n;

[0048] L≥max(c,d,e);

[0049] Where L represents the optimal horizontal spacing of the tension string.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] The present invention can effectively solve the problem of excessively wide horizontal spacing when multiple large-section conductors are split, improve the stress of the iron tower and the tension string structure, enhance the safety and stability of the tension string in extremely heavy ice areas, and take into account the aesthetics of the hardware string structure.

[0052] The present invention adopts a multi-connection setting for the extra-heavy ice zone tension string and adopts a vertical layered arrangement, thereby avoiding the situation that uneven force is very likely to occur when the movement of the hardware is restricted, resulting in excessive load on individual hardware and insulators; avoiding the problem that the equalizing ring is large in size, which is not conducive to installation and deformation; and avoiding the problem that the tower head cross arm needs to be lengthened accordingly due to the wide horizontal dimension, which increases the tower weight and is also difficult to control the gap with the tower body or cross arm; making the width of the tension string smaller, the hardware combination is simpler than the horizontal arrangement, the cross arm length can be reduced, and the connection between the tension string and the conductor is easier.

[0053] The present invention obtains the optimal connection spacing through calculation and design of the electrical performance of the tension string, the offset distance and the ice-shedding jump distance; so that the distance between multiple tension strings and the field strength distribution of the tension strings and the insulators between the strings do not contact or collide under operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 is a flow chart of the present invention;

[0055] Figure 2 1 is a top view schematic diagram of a vertically arranged conductor tension string in the present invention;

[0056] Figure 3 It is a front view schematic diagram of a vertically arranged conductor tension string in the present invention; DETAILED DESCRIPTION

[0057] In this application, unless otherwise specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, they can refer to fixed connections, removable connections, or integration; they can refer to direct connections or indirect connections through an intermediary; they can refer to internal communication between two components or interactions between two components. The terms "first," "second," and similar terms mentioned in this application do not denote any order, quantity, or importance; they are simply used to distinguish between different components. Similarly, terms such as "a" or "an" do not indicate a quantitative limitation, but rather indicate the presence of at least one. In the implementation of this application, "and / or" describes an association relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. In the description of the embodiments of this application, unless otherwise specified, "plurality" means two or more. For example, "plurality" refers to two or more positioning posts. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0058] The present invention is described in detail below.

[0059] like Figure 1-Figure 3 As shown,

[0060] A method for configuring a vertically arranged conductor tension string in an extremely heavy ice area specifically comprises the following steps:

[0061] Step S1: Determine the mechanical strength of the tension string. The mechanical strength of the tension string must meet the requirements of the regulations, including the safety factor, wear resistance of the hardware connection points, maximum rotation angle of the tension tower, rationality of the connection between insulators and hardware, and compatibility with the jumper drainage.

[0062] Specifically, the mechanical strength of tension strings must meet the safety factors specified in the regulations: the safety factor for general line disc insulators must be no less than 2.7, the annual load must be no less than 4.0, the line-break load must be no less than 1.8, the disconnection load must be no less than 1.5, and the rare load must be no less than 1.5. The safety factor for general line hardware must be no less than 2.5, the line-break load must be no less than 1.5, the disconnection load must be no less than 1.5, and the rare load must be no less than 1.5.

[0063] When the conductors are in dynamic situations such as jumping or dancing, each connection point (including the connection points on the tower) should be wear-resistant and fatigue-resistant;

[0064] When there is an error or change in the length of the conductor or insulator, there is a possibility of adjustment or self-recovery for the difference in tension distribution between the links;

[0065] Based on strength requirements, UHV line tension strings must be designed with multiple connections. From the perspective of line hanging point reliability, it is most reliable to have each connection fixed to the tower. Furthermore, the tension string itself has a simple structure and can reduce the cost of the string itself.

[0066] The spacing between tension strings changes with the angle of the line rotation. The spacing between tension strings should take into account the maximum possible rotation angle on the tension tower. The insulators of different strings that are close to each other should be kept at a sufficient distance to avoid the possibility of partial discharge and collision between them. Based on this consideration, according to the rotation angle of the tower and the requirements of the electrical distance, the spacing between multiple tension strings should be adjusted according to the spacing between the multiple strings, and on the side of the multiple strings close to the tower, the spacing between the multiple strings should be adjusted to ensure that the spacing between the multiple strings is above the safe value.

[0067] To prevent one or more conductors from falling off due to the breakage of a certain section of the tension string, the sections of the tension strings are connected together near the conductors. A star-shaped connecting plate is used, and the number of its branches is the same as the number of sub-conductors in one phase, which serves as a transition between the conductors and the tension string.

[0068] When the jumper is pulled down from the tension string, it has a cylindrical shape that satisfies multiple splits and corresponding split spacing.

[0069] Step S2: Determine the number of tension strings. For heavy ice areas, the number of tension strings is at least six.

[0070] According to the conductor model and safety factor used, multiple combination strings are formed by combining different tonnage and number of connections; common combinations are shown in the following table.

[0071]

[0072] Conduct technical and economic comparisons of different tonnages and different numbers of units in terms of the number of insulators, hardware weight, and ease of construction, and arrive at the optimal combination of number of units and tonnage;

[0073] For extremely heavy ice areas of 40mm and above, considering the influence of the weight of the ultra-high voltage tension string, a six-link tension string is required.

[0074] Step S3: determining the arrangement type of the tension string, wherein the arrangement type is a vertical layered arrangement;

[0075] For multi-linked tension strings, if a conventional horizontal arrangement is adopted, the entire tension string is distributed relatively wide. On the one hand, multiple combined connecting plates are required. When the movement of the hardware is restricted, uneven force is easily caused, resulting in excessive load on individual hardware and insulators. On the other hand, the grading ring is large in size, which is not conducive to installation and is also prone to deformation. Due to the wide horizontal dimension, the tower head cross arm needs to be lengthened accordingly, increasing the tower weight, and it is also difficult to control the gap with the tower body or cross arm. For this reason, the present invention adopts a vertical layered arrangement for the multi-linked tension string.

[0076] Specifically, when the number of multiple-unit tension strings is six, a two-layer vertical arrangement with three units in each layer is adopted; the advantages of adopting this arrangement are that the width of the tension string is smaller, the combination of hardware is simpler than the horizontal arrangement, the length of the crossarm can be reduced, and the connection between the tension string and the conductor is easier, which effectively solves the problems existing in the horizontal arrangement.

[0077] Step S4: Determine the number of hanging points of the tension string;

[0078] From the perspective of the reliability of the hanging points, it is most reliable to fix each section of the tension string separately on the tower. The tension string itself has a simple structure and can also reduce the cost of the string itself. However, it will inevitably increase the weight of the tower material. This requires whether the hanging points can be simplified as much as possible to shorten the distance between hanging points and reduce the size of the crossarms while ensuring safety and economy.

[0079] For the tension string type, if only one hanging point is used, when the hardware connected to the tower fails, it means that the conductor of the faulty phase will directly fall to the ground, which will cause a major accident. Considering the importance of ultra-high voltage lines and combining the design and operation experience of domestic ultra-high voltage lines, it is recommended that the tension string adopt a double or multi-hanging point type;

[0080] For the six-link tension string, a three-hanging-point arrangement is considered from the perspective of even distribution of force and stability.

[0081] Step S5: Determine the optimal spacing of the multiple-unit tension strings by calculating the electrical distance, offset distance, and ice-shedding jump distance of the multiple-unit tension strings.

[0082] The distance between multiple tension strings is determined based on the field strength distribution of the tension strings and the premise that the insulators between the strings do not contact or collide under operating conditions. That is, the distance between the strings is mainly determined by the electrical performance of the multiple tension strings, the offset distance and the ice-shedding jump distance.

[0083] The requirements for electrical performance on the spacing between couplers, i.e. the requirements for the electrical distance of multi-coupled tension strings:

[0084] Through the pollution withstand voltage test analysis of multi-junction tension strings in extremely heavy ice areas, it was found that under certain salt density conditions, when the net spacing of the multi-junction parallel strings (the distance between the strings minus the diameter of the insulator disc) is greater than a certain value a, the discharge process can develop independently; at the same time, when the pollution flashover voltage of the multi-junction parallel strings and the single string is compared, when the net spacing of the multi-junction parallel strings (the distance between the strings minus the diameter of the insulator disc) is greater than a certain value b, the pollution flashover voltage of the two is equivalent. Therefore, when the net spacing of the multi-junction parallel strings is greater than a and greater than b, it is considered that the distance between the strings meets the electrical distance; that is, the electrical distance of the multi-junction tension string is calculated as:

[0085] L1≥max(a,b);

[0086] Wherein, L1 represents the electrical distance of the multi-connected tension string;

[0087] a represents the minimum clear distance when multiple tension strings are connected in parallel and the discharge process can develop independently;

[0088] b represents the minimum clear space distance when multiple tension strings are connected in parallel and the pollution flashover voltage of a single tension string is the same.

[0089] Requirements for offset distance and couplet spacing:

[0090] A notable feature of UHV tension strings is their long length. Besides the insulator disc diameter, the increased wind load on the string can cause the string to deflect, similar to sag, resulting in insulators approaching or colliding. Therefore, the required spacing must be greater than the maximum deflection of the tension string.

[0091] That is, the offset distance of the multi-link tension string is calculated as:

[0092] L2≥fsin(atan(G4 / G1))+n;

[0093] Wherein, L2 represents the offset distance of the multi-connected tension string;

[0094] f represents the sag value of the multi-connected tension string under the approximate catenary line;

[0095] G4 represents the horizontal load of the multi-connected tension string under high wind conditions;

[0096] G1 represents the vertical load of the multi-connected tension string under high wind conditions;

[0097] n represents the maximum diameter of the insulator.

[0098] Requirements for the spacing between ice-skipping jump couplets:

[0099] In sections with heavy ice, ice shedding is prone to jumps, and the jump amplitude increases with increasing ice thickness. Ice shedding jumps can be divided into ice shedding jumps on the tension string itself and ice shedding jumps on the conductor. After ice shedding jumps occur, the tension string vibrates violently. Due to the long length of the UHV line tension string, the swing amplitude of the insulator is large.

[0100] That is, the ice-shedding jump distance of a multi-connected tension string is calculated as:

[0101] L3≥max(c,d,e);

[0102] Among them, L3 represents the ice-shedding jump distance of the multi-connected tension string;

[0103] c represents the jump distance caused by the de-icing of the multi-connected tension string itself;

[0104] d represents the jump distance of the multi-connected tension string caused by the conductor ice shedding;

[0105] e represents the comprehensive jump distance of the multi-connected tension string caused by the simultaneous ice shedding of the string itself and the conductors.

[0106] The optimal joint spacing includes the optimal joint spacing in the horizontal direction and the optimal joint spacing in the vertical direction;

[0107] Specifically, such as Figure 3 As shown in the figure, the optimal vertical spacing of multiple tension strings is:

[0108] H≥max(a,b);

[0109] H≥fi+n;

[0110] H≥max(c,d,e);

[0111] Wherein, H represents the vertical spacing of multiple tension strings;

[0112] a represents the minimum clear distance between multiple tension strings connected in parallel and able to develop independently during the discharge process;

[0113] b represents the minimum clear space distance when multiple tension strings are connected in parallel and the pollution flashover voltage of a single tension string is the same;

[0114] n represents the maximum diameter of the disc insulator;

[0115] c represents the jump distance caused by ice shedding of the tension string itself;

[0116] d represents the jump distance of the tension string caused by the conductor falling off the ice;

[0117] e represents the comprehensive jump distance caused by the simultaneous ice shedding of the tension string itself and the conductor;

[0118] fi represents the maximum sag value of the tension string under icing conditions.

[0119] Specifically, such as Figure 2 As shown in the figure, the optimal horizontal spacing of multiple tension strings is:

[0120] L≥max(a,b);

[0121] L≥fsin(atan(G4 / G1))+n;

[0122] L≥max(c,d,e);

[0123] Where L represents the optimal horizontal spacing of the tension string.

[0124] The present invention is not limited to the aforementioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A method for configuring a vertically arranged conductor tension string in an extremely heavy ice area, characterized in that: The specific steps include: Step S1: determining the mechanical strength of the tension string; Step S2: determining the number of tension strings, wherein the number of strings is at least six; Step S3: determining the arrangement type of the tension string, wherein the arrangement type is a vertical layered arrangement; Step S4: determining the number of hanging points of the tension string, wherein the number of hanging points is at least two groups; Step S5: Determine the optimal spacing of the multiple-unit tension strings by calculating the electrical distance, offset distance, and ice-shedding jump distance of the multiple-unit tension strings.

2. The method for configuring a vertically arranged conductor tension string in an extremely heavy ice zone according to claim 1, characterized in that: When the number of units is six, a two-layer vertical layout is adopted, with three units on each layer.

3. The method for configuring a vertically arranged conductor tension string in an extremely heavy ice zone according to claim 1, characterized in that: The optimal link distance includes an optimal link distance in the horizontal direction and an optimal link distance in the vertical direction.

4. The method for configuring a vertically arranged conductor tension string in an extremely heavy ice zone according to claim 3, characterized in that: The electrical distance of the multi-connected tension string in step S5 is calculated as: L1≥max(a,b); Wherein, L1 represents the electrical distance of the multi-connected tension string; a represents the minimum clear distance when multiple tension strings are connected in parallel and the discharge process can develop independently; b represents the minimum clear space distance when multiple tension strings are connected in parallel and the pollution flashover voltage of a single tension string is the same.

5. The method for configuring a vertically arranged conductor tension string in an extremely heavy ice zone according to claim 4, characterized in that: The offset distance of the multi-link tension string in step S5 is calculated as: L2≥fsin(atan(G4 / G1))+n; Wherein, L2 represents the offset distance of the multi-connected tension string; f represents the sag value of the multi-connected tension string under the approximate catenary line; G4 represents the horizontal load of the multi-connected tension string under high wind conditions; G1 represents the vertical load of the multi-connected tension string under high wind conditions; n represents the maximum diameter of the insulator.

6. The method for configuring a vertically arranged conductor tension string in an extremely heavy ice zone according to claim 5, characterized in that: In step S5, the ice-shedding jump distance of the multi-connected tension string is calculated as: L3≥max(c,d,e); Among them, L3 represents the ice-shedding jump distance of the multi-connected tension string; c represents the jump distance caused by the de-icing of the multi-connected tension string itself; d represents the jump distance of the multi-connected tension string caused by the conductor ice shedding; e represents the comprehensive jump distance of the multi-connected tension string caused by the simultaneous ice shedding of the string itself and the conductors.

7. The method for configuring a vertically arranged conductor tension string in an extremely heavy ice zone according to claim 3, characterized in that: The optimal vertical spacing of the multi-link tension string is: H≥max(a,b); H≥fi+n; H≥max(c,d,e); Wherein, H represents the vertical spacing of multiple tension strings; a represents the minimum clear distance between multiple tension strings connected in parallel and able to develop independently during the discharge process; b represents the minimum clear space distance when multiple tension strings are connected in parallel and the pollution flashover voltage of a single tension string is the same; n represents the maximum diameter of the disc insulator; c represents the jump distance caused by ice shedding of the tension string itself; d represents the jump distance of the tension string caused by the conductor falling off the ice; e represents the comprehensive jump distance caused by the simultaneous ice shedding of the tension string itself and the conductor; fi represents the maximum sag value of the tension string under icing conditions.

8. The method for configuring a vertically arranged conductor tension string in an extremely heavy ice zone according to claim 6, characterized in that: The optimal horizontal spacing of the multi-link tension string is: L≥max(a,b); L≥fsin(atan(G4 / G1))+n; L≥max(c,d,e); Where L represents the optimal horizontal spacing of the tension string.

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