Novel terminal tower for phase sequence adjustment of single-circuit power transmission line

Abstract

A novel terminal tower for phase sequence adjustment of a single-circuit transmission line comprises an iron tower, an upper-layer cross arm arranged on the top of the iron tower, a jumper support arranged on the side of the upper-layer cross arm, a lower-layer cross arm arranged on the lower portion of the iron tower, and a small cross arm arranged on the outer side of the corner of the iron tower and located between the upper-layer cross arm and the lower-layer cross arm. The C phase serving as a corner inner phase directly connects the lines of the line side and the transformer substation side through a first jumper string; the corner middle phase-A phase at the line side is connected to the jumper wire bracket at the inner side of the corner through a second jumper wire string, then is wound to the transformer substation side and is connected with the transformer substation side A-phase wire of the small cross arm; and the corner outer phase-B phase directly connects the lines of the line side and the transformer substation side through a third jumper string. Compared with a conventional single-loop terminal tower, the tower weight increase is small; compared with an existing F-shaped tower, the weight of the tower can be reduced by about 50%.

Description

Technical Field

[0001] The utility model relates to a novel terminal tower used for phase sequence adjustment of a single-circuit power transmission line. Background Art

[0002] With the development of social economy, the demand for electricity as an energy source has increased year by year, the construction of power grids has continued to increase, and the power system grid has become more and more complex. Among the newly built lines, there are fewer and fewer lines directly from station A to station B. The interconnection between substations through reconnection, π connection, T connection, etc. has become an important option for power system access solutions. Due to the limitations of the phase sequence arrangement of existing lines, the access system through reconnection, π connection, T connection and other transformation methods inevitably involves the problem of phase sequence adjustment. In the actual existing projects, there are some solutions, but they cannot meet all engineering needs.

[0003] When the line is restricted by external conditions and needs to be phased at the incoming line of the substation, there are two main common practices.

[0004] 1) The first solution: using F-type terminal tower phase adjustment, this solution uses the difference in the arrangement of three-phase conductors on the F-type terminal tower and the frame to adjust the phase sequence. The advantage is that for any phase sequence, phase adjustment can be achieved through the spatial arrangement of conductors; the disadvantage is that the F-type terminal tower is essentially modified from the double-circuit terminal tower, the tower weight is relatively large, resulting in waste of poles and towers.

[0005] 2) The second solution: Use a single-circuit terminal tower with an auxiliary support to achieve phase adjustment. The advantage of this solution is that it can achieve cyclic phase adjustment and phase adjustment of the inner phase and middle phase of the corner; the disadvantage is that it cannot achieve phase adjustment of the outer phase and middle phase of the corner.

[0006] Based on the actual needs of the project, it is necessary to design a single-circuit terminal tower for phase adjustment of the outer phase and the middle phase of a single-circuit corner without significantly increasing the weight of the tower. Utility Model Content

[0007] The technical problem to be solved by the utility model is: how to meet the phase sequence adjustment problem required by all projects. The utility model proposes a novel single-circuit terminal tower for phase sequence adjustment at the transformer substation side.

[0008] In order to achieve the above object, the utility model is realized by the following technical solutions:

[0009] A new type of terminal tower for phase sequence adjustment of a single-circuit power transmission line comprises an iron tower, an upper cross arm is arranged on the top of the iron tower, a jumper bracket is arranged on the side of the upper cross arm, a lower cross arm is arranged at the bottom of the iron tower, a small cross arm is arranged on the outer side of the corner of the iron tower, and the small cross arm is located between the upper cross arm and the lower cross arm;

[0010] Phase C, which is the phase in the corner, directly connects the lines on the line side and the substation side through the first jumper string;

[0011] The phase A in the corner of the line side is connected to the jumper bracket on the inner side of the corner through the second jumper string, and then goes around to the substation side and is connected to the substation side A phase conductor of the small cross arm;

[0012] The outer phase of the corner - phase B, directly connects the lines on the line side and the substation side through the third jumper string.

[0013] The length of the small cross arm is shorter than that of the lower cross arm.

[0014] Compared with the prior art, the utility model has the following beneficial effects: compared with the conventional single-circuit terminal tower, the utility model has a smaller increase in tower weight; compared with the existing F-type tower, the tower weight can be reduced by about 50%. The utility model can also be used for phase sequence adjustment in the middle of the line, and the adjustment process is consistent with the above. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is the principle diagram of the utility model;

[0016] Figure 2 It is a front view of the iron tower of the utility model. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0018] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0019] like Figure 1 , Figure 2 As shown, a new type of terminal tower for phase sequence adjustment of a single-circuit transmission line is used when it is necessary to realize phase adjustment between the outer phase and the middle phase of a single circuit in a substation. The specific introduction is as follows.

[0020] exist Figure 1In the figure, the phase sequence of line side 1 is arranged from left to right: B, A, C, where phase B is the outer phase, phase A is the middle phase, and phase C is the inner phase. The phase sequence of substation side 2 is arranged from left to right: A, B, C. Phase A and phase B need to complete phase switching.

[0021] A new type of terminal tower for phase sequence adjustment of a single-circuit power transmission line comprises an iron tower 3, an upper cross arm 5 is arranged on the top of the iron tower 3, a jumper bracket 10 is arranged on the side of the upper cross arm 5, a lower cross arm 6 is arranged at the bottom of the iron tower, and a small cross arm 4 is arranged on the outer side of the corner of the iron tower 3, the small cross arm 4 is located between the upper cross arm 5 and the lower cross arm 6, and the length of the small cross arm 4 is shorter than that of the lower cross arm 6.

[0022] During phase adjustment, phase C, which is the inner phase of the corner, is not adjusted, and the lines on the line side 1 and the substation side 2 are directly connected through the first jumper string 7; the middle phase at the corner of the line side 1 - phase A is connected to the jumper bracket 10 on the inner side of the corner through the second jumper string 11, and then goes around to the substation side 2 and is connected to the substation side A phase conductor 8 of the small cross arm 4; the outer phase of the corner - phase B, is directly connected to the lines on the line side 1 and the substation side 2 through the third jumper string 12.

[0023] When connected to the substation frame 9, since there is a large vertical distance between the A-phase and B-phase hanging points on the substation side of the tower, the spacing between the A-phase and B-phase conductors in space can meet the relevant safety distance requirements, thereby ensuring smooth phase adjustment.

[0024] The principle adopted by this utility model is:

[0025] The three-phase conductors are arranged on the line side 1 of the tower in the same manner and position as the conventional "stem" type tower. The key point of the utility model is to add a small cross arm 4 outside the corner. Due to the addition of the small cross arm 4, the tower head height of the tension tower is appropriately increased compared with the conventional "stem" type tension tower.

[0026] The small cross arm 4 needs to meet the phase spacing and ground wire offset requirements with the lower cross arm 6. Its length is shorter than the lower cross arm 6, and the spacing with the lower cross arm 6 can refer to the interlayer arrangement of the double-circuit tension tower. Since the small cross arm 4 is connected to the conductor on the frame side 2, the tension and load are about 20% of the line side 1, and there is only one-phase conductor, the tower weight increase is smaller than that of the conventional single-circuit terminal tower; compared with the existing F-type tower, the tower weight can be reduced by about 50%.

[0027] This tower can also be used to adjust the phase sequence in the middle of the line, and the adjustment process is the same as above.

[0028] The above is only a preferred embodiment of the present invention. It should be pointed out that those skilled in the art can make several changes and improvements without departing from the overall concept of the present invention, and these should also be regarded as the protection scope of the present invention.

Claims

1. A new type of terminal tower for phase sequence adjustment of single-circuit power transmission lines, characterized in that: It comprises an iron tower (3), an upper cross arm (5) is arranged at the top of the iron tower (3), a jumper bracket (10) is arranged on the side of the upper cross arm (5), a lower cross arm (6) is arranged at the bottom of the iron tower, and a small cross arm (4) is arranged on the outside of the corner of the iron tower (3), and the small cross arm (4) is located between the upper cross arm (5) and the lower cross arm (6); Phase C, which is the phase in the corner, directly connects the lines on the line side (1) and the substation side (2) through the first jumper string (7); Phase A, the middle phase of the corner of the line side (1), is connected to the jumper bracket (10) on the inner side of the corner through the second jumper string (11), and then goes around to the substation side (2) and is connected to the substation side A phase conductor (8) of the small cross arm (4); The outer phase of the corner - phase B, directly connects the lines on the line side (1) and the substation side (2) through the third jumper string (12).

2. A new type of terminal tower for phase sequence adjustment of a single-circuit power transmission line according to claim 1, characterized in that: The length of the small cross arm (4) is shorter than that of the lower cross arm (6).

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