RU169483U1 - VL wire distance coordination device - Google Patents

Abstract

The proposed device for coordinating the interfacial distances of the OHL wires, which consists in the fact that the permissible voltage of the wires is increased to 60% of their tensile strength, and the interphase distances of the wires are increased with the help of adjustable adjustable traverses up to 1.5 times in comparison with the standard ones, it allows you to coordinate simultaneously among themselves to safe sag values, interphase distances and wire dance parameters, and increase the reliability of the lines by an order of magnitude compared to standard ones. About the device is carried out without additional capital costs.

Description

The utility model relates to the field of electric power and can be used in the construction and reconstruction of overhead power lines to protect against dangerous icing conditions and “dancing” of wires in areas subject to ice-wind loads.

In mid-voltage overhead lines, voltages of 6-20 kV, in accordance with PUE-7, wires are mounted with permissible voltages of 35-45% of the limit of their strength values (Electrical Installation Rules, ed. 7, 2003)

There are well-known analogs of overhead lines with a traverse and hook arrangement of wires (Typical project of the Selenergoproekt “6-20 kV overhead power lines”). The disadvantage of these structures is the fixed and insufficient size of the interphase distances between the wires and, as a result, massive gouging and burns of wires, damage to supports and structural elements from ice-wind loads.

This is confirmed by annual mass accidents in power grids in most regions of the country: Sakhalin, Kamchatka, Magadan, Primorye, Altai, the regions of the Center, North-West, South-West, Krasnodar Territory, the Caucasus, etc.

The closest prototype to the claimed one is the design of all-welded metal traverses with a triangular arrangement of wires (Typical project of the Selenergoproekt “Design of overhead power lines 6-20 kV” and “Installation tables of the Selenergoproekt of the voltage and arrows of the wire sag of the 6–20 kV overhead lines”).

The disadvantages of this prototype are massive whipping and burnouts of wires, damage to supports and structural elements, the inability to control the interfacial distances of the wires, the low reliability of the overhead lines and icy-wind conditions.

The objective of the utility model is to develop a device that simultaneously coordinates three factors: arrows of wire sag, distance between wires and dance parameters (large “a” and small “b” axes of wire dance ellipses) and effective reliability of power lines in icy-wind modes.

The problem is achieved in that in the claimed device, containing the traverse and hook fasteners of wires, the permissible voltage of the wires is increased to 60% of the ultimate strength values, while the wires are mounted on a sliding adjustable metal traverse, where the upper wire is mounted on the headband, and two lower - separately on the horizontal traverse, with an increase in the vertical distance between the wires up to 1.5 times in comparison with standard ones.

Table 4 shows the data of a comparative analysis of the overall arrows of the sag f _g and the interphase distances h for all brands of traditional wires, types of supports for various glaze areas according to standard overhead lines in the Bashkir region, as well as for other similar regions of the country. From table 4 it is seen that the overall arrows of the sag are greater than the vertical distances. And, as a result, the dancing ellipses in Fig. 1 not only close together at dangerous distances, but also intersect, as a result of massive lashing and burns of wires.

For greater clarity, Table 1 shows, based on the solutions of the quadratic equation of state of the wire in the span, the ratio of f _g to h for several brands of the most used wires. From table 1 it is seen that the overall arrows of the sag 1.16-1.66 times greater than the vertical distances. It follows that these parameters are not coordinated with each other, which explains the massive accidents in the power grid.

Table 5 shows similar data, but for lines that use increased wire strands up to 60% of [σ _bp ] instead of 35-45% of [σ _bp ] regulated by PUE and vertical distances are increased up to 1.5 times compared to standard. From table 5 it follows that the vertical distances between the wires are greater than the overall arrows of the sag and specifically, as follows from the calculations given in table 2, 1.22-1.69 times. In these cases, the dancing ellipses in Fig. 2 do not approach and do not intersect. Thus, there are three parameters on overhead lines with increased pulling and wire extension: interfacial distances S, overall arrows f _g and dancing parameters a and b are coordinated with each other and the lines operate reliably in icy-wind modes.

To realize the extension of the wires, an adjustable adjustable metal traverse was developed: the upper wire is mounted on the headband, the two lower ones are separately mounted on the horizontal traverse.

The calculations of the ellipses of the “dance” of wires were carried out according to the scientific methodology of the Institute of VNIIE (Methodological guidelines for zoning of territories according to the frequency of repeatability and intensity of the dance of wires, RD 34.20.184-91, approved on 15.11.1991).

To test the effectiveness of the claimed device in the Bashkiria region, 5315 km of 10 kV overhead lines of high reliability were built in various glaze areas, on which increased strains and wire extension were applied.

Over two ice seasons, statistics on the operation of lines in parallel with standard lines were kept. During this period, strong winds of up to 20-22 m / s, intense icy conditions of up to 80 mm and severe frosts of -40 ° C were noted. The data are shown in table 3. From table 3 it follows that the reliability of the lines was increased by 7.1-10.2 times, i.e. an order of magnitude. Moreover, this was achieved without additional capital costs. All the same, due to the natural drawing of wires, the personnel periodically carries out the banner of wires, installing one or another sag.

In this way:

 on standard 6-20 kV overhead lines, the sag of the wires, the interphase distances and the parameters of the ellipses of the wire dancing are not coordinated with each other and the lines in the ice-wind regions are unreliable;

on a 6-20 kV overhead line with increased traction up to 60% [σ _BP ] and the extension of the wires of the sag of the wires, the interfacial distances and the parameters of wire dancing are coordinated with each other and their reliability increases by an order of magnitude compared to standard overhead lines;

 the use of increased wire strains and increased interfacial distances is carried out without additional capital costs.

Table 1

Meteorological parameters and VL parameters l and h Mark of wire / gauge boom f _gab , m
AZ-50 AC-50 AN-70 AZ-70 b = 20 mm; v _g = 1 5 m / s; t = - 5 ° C; l = 60 m; h = 0.94 m 1.51 1,64 1,6 1.15 The ratio n = f _gab / h; time 1.37 1.49 1.45 1.05 b = 20 mm; v _g = 20 m / s; t = - 5 ° C; l = 60 m;
h = 1.1 m 1.72 1.65 1.83 1.28 The ratio n = f _gab / h; time 1,56 1,5 1.66 1.16

table 2

Meteorological parameters and VL 1 and h parameters Mark of wire / gab. Boom f _gab ; - 5 ° C, m
AZ-50 AC-50 AN-70 AZ-70 b = 20 mm; v _g = 15 m / s; t = -5 ° C; l = 60 m; h = 1.4 m 0.98 0.89 1,04 0.83 The ratio n = h / f _gab ; time 1.42 1,57 1.34 1.68 b = 20 mm; v _g = 20 m / s; t = -5 ° C; l = 60 m; h = 1.4m 1.06 0.96 1.14 0.83 The ratio n = h / f _gab ; time 1.32 1.46 1.22 1,69

Table 3

Indicators Units 1 year 1 year 2 year 2 year meas. II III IV and above II III IV and above ECU ECU ECU ECU Number of shutdowns V L 10 off 19 26 27 42 kV increased reliability The share of overhead lines % 7 twenty 12 26 reliability of the total length of overhead lines . The specific number of shutdowns off 1,5 1,2 1,5 1,5 VL increased at 100 reliability km / g Number of outages off 1785 464 1755 608 standard overhead lines The share of standard overhead lines from % 93 80 88 74 total length The specific number of shutdowns off 15.3 8.3 13.3 10.7 standard overhead lines at 100 km / g Increased reliability time 10,2 7.0 9.0 7.1 overhead lines

Literature used when applying for a utility model

"Method and device for coordinating the distances of wires of overhead lines"

1. Electrical Installation Rules, ed. 7, 2003

2. A typical project of the Selenergoproekt “6-20 kV Overhead Power Lines”.

3. A typical project of the Selenergoproekt “Design of overhead power lines 6-20 kV”.

4. Installation tables of the Selenergoproekt of the voltage and arrows of the sag of the wires of 6–20 kV overhead lines.

5. Guidelines of the Institute VNIIE on zoning of territories according to the frequency of repeatability and intensity of dancing wires, RD 34.20.184-91, approved. November 15, 1991

Claims (1)

A device for coordinating the interphase distances of OHL wires, containing traverse and hook fasteners of wires, characterized in that the permissible voltage of the wires is increased to 60% of their ultimate strength values, while the wires are mounted on a sliding adjustable metal traverse, where the upper wire is attached to the headband, and the two lower ones - separately on the horizontal traverse with an increase in the vertical distance between the wires up to 1.5 times in comparison with the standard ones.

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