SU1476559A1 - Overhead power transmission line - Google Patents

Abstract

The invention relates to power engineering and can be used in the construction of high voltage power lines. The goal is to improve the operating modes of the electrical equipment of the line by reducing the electrical asymmetry of the line. The air line contains the same type of supports and phase wires located at the vertices of a non-equilateral triangle. The supports of one of the halves of the line are turned in relation to the supports of the other half by an angle of 180 °. In this case, the currents and voltages of the reverse and zero sequences are reduced in the line. 3 il.

Description

31476559

between the system of direct and inverse sequences, which determines the magnitudes of the currents and stresses of the sibling sequence, for a line with similar supports that are equally spaced along the entire length, can be found from the expression

2 g g - | (2лЛ + а2вв + У2 2 (a2Z, + aZAC + ZBC),

J / 46 e Z, - and Z

her) +

(one)

1 Gz

intrinsic and mutual resistance of phases; line length;

and -0.5+ - j - rotation operator.

Since the intrinsic resistances are almost equal, the expression) can be written as follows:

Z21 C I (ZAB + Z DB) j (2L8 -ZAC

(is D

OJ45-21. 3

J6c

V5

2

3-o lg

lg alv adg

 alvads

)

(2)

where a - is the distance between adjacent phases; m - equivalent depth

current.

For the line made by the proposed solution, after such transformations we get:

7. OJ45-21 I o

- 1-

iax & a - / (c

The real parts of the expressions in brackets of equations (2) and (3) are equal. In the expression (in parentheses) of equation (2), in addition, there is an imaginary term, which for real lines with a triangular phase arrangement is not 0. Thus, for the moduli of mutual resistances, we have the inequality

I I - I 7 I SD b

I Ј 21 I I 2i I (4

which proves the reduction of asymmetry on the reverse sequence in the proposed solution.

0

five

0

five

0

five

0

five

0

five

The currents and voltages of the reverse and zero sequences in the implementation of the proposal are reduced by 2-4 times. So, for example, as a result of the calculation of a non-transposed line with a voltage of 220 kV, 120 km long, made on IB220-1 supports, the following results were obtained when transferring power (200 + j 100) MBA: the negative sequence current at the transmitting end is 4.7A, zero sequence - 5.1 A; the reverse sequence voltage at the receiving end of the line is 0.45 kV, the zero sequence is 0.06 kV. With the proposed arrangement of the supports, the corresponding design values are as follows: negative sequence current 1.6 A; zero sequence current 1.8 A; negative sequence voltage of 0.12 kV; zero sequence voltage 0.02 kV.

The obtained results show that the use of the invention will make it possible to refuse transposition on almost all the lines with a triangular arrangement of phases longer than 100 km, for which the normative documents require its implementation. Due to the fact that the implementation of the proposed solution does not require any additional costs, it is obvious expediency of its use for lines of small length.

The technical and economic effect of reducing energy losses and improving its quality, improving conditions for transmitting high-quality signals, increasing reliability, reducing construction costs by eliminating the use of transposition supports and reducing the desensitization of relay protection bodies depends on the characteristics of the HV line and the adjacent network and can be determined with a specific design.

Claims (1)

Invention Formula An overhead transmission line containing uniform supports with the arrangement of phase conductors at the tips of a non-equilateral triangle, in order to improve the operating modes of the electrical equipment of the line by reducing the electrical asymmetry of the line, the supports of one half of the line are deployed relative to the supports of the other AT t -L. N5 V Have H at an angle of 180s, and fuses between eight g J } Jjxjjj phage1 phi.2