SU1377959A1 - End substation for connection to remote a.c. power line - Google Patents

Abstract

The invention relates to electrical engineering. The purpose of the invention is to limit the overvoltage on the neutral of the primary winding of the shunt tr-ra. The secondary winding of port 2 is shunted by the reactance 3. The reduction of overvoltages on the neutral of the primary winding of pipe 2 is achieved as a result of the introduction of an additional reaction into the circuit of its primary winding. tive resistance 4. 2 Il.

Description

§

WITH

 Ni

with O1

FIG. one

 The invention relates to electrical engineering, in particular, to main circuits of large-scale AC power lines, and can be used for terminating connections to long AC lines or for communication on alternating current of mutually remote systems.

The purpose of the invention is to eliminate operating overvoltages on the neutral of the primary winding of the shunt transformer in a rebuilt circuit when used as the terminal.

FIG. 1 shows the scheme of performance of the terminal substation; in fig. 2 - the same.

FIG. 1 the primary winding of the parallel transformer 1 is connected between phase and neutral. The secondary winding of the parallel transformer 1 and the secondary winding of the serial transformer 2, shunted by the reactance 3, are connected in series. The primary winding of the serial transformer 2 is connected between the phase and the neutral through additional reactance 4.

Transformer transformation ratios are

K, -KD If - 4. 2ii

- KB

where K is the transformation ratio

schemes in general; B and D - the parameters of the quadrupole

power transmission circuits;

Xj - reactance

shunt secondary winding of the transformer 2. A transmission station (system) is connected to the terminals 5, and a transmitting end of the line is connected to the terminals 6.

FIG. 2 shows a modification of this circuit, where the additional reactance 4 is connected between the linear inputs of transformers 1 and 2. The rest of the circuit is similar.

The operation of the circuits of FIG. 1 and FIG. 2 is no different; therefore, it suffices to consider the work of one of them.

The scheme (Fig. 1) works as follows.

With its load on the receiving end of the power transmission line with current Ig, voltage and current at the transmitting end of the line

. V. And V,

jbt ,,

I, j CV + DIo

(for simplicity, hereinafter active resistances are not taken into account)

The secondary winding of the parallel transformer 1 current flows

t t L °

 11 P f

and its linear winding respectively

I-CD

eleven

1 ii.

01 „.

The rest of the current I flows through the primary winding of the sequence. telny transformator 2 and additional reactance 4

iii

i, -i

jcv;

Reactive power compensation in the amount of

n t PG "-X. X 1 pi..iA 7 H -. „+ To J V --ALV

Induced in the secondary winding of a serial transformer 2 current

1 0 to, - KI

PIC

Ha

e

which, closing through the shunt resistance B and adding to the current Ifl, also flowing through this resistance, creates a voltage drop

iV ,, jX, (l + V - KBCV + jb i.

The latter is geometrically summed with the secondary voltage of the parallel transformer 1

jv ,, -K (v, + jK ,,) + jx ,, i “b.

-KADVe + j KBD + KX ,, D X

And it results in Vn KV. + J KD (B4-X, D) t.

 KV, + j (B + X,) +,.,

providing the effect of connecting the transmitting station (system) to the receiving end of the transmission line (V KVo) through resistance

. X X, + (B + X ,, и).

The value of this resistance can be obtained, in principle, any, due to proper selection of the magnitude and nature (inductance, capacitance) of the shunt resistance 3 and the dissipation resistance of the parallel transformer X, X (they can be artificially reduced or increased)

This creates the effect of a given proximity of the mutually distant elements of the union, which facilitates the conditions of their parallel operation, regardless of the length of the transmission lines connecting them.

The effect is preserved as long as the parameters of the power transmission lines and the values of K-, Kr, X5, X4 terminal circuit remain unchanged. No KU line installation is required. Due to parametric detuning mode

Moving the end connection to the line and varying the transmitted active power from zero (idle) to natural voltage throughout the homogeneous line does not exceed the nominal one.

Using the proposed two-transformer circuit of terminal substations, power stations can be connected to long uncompensated AC lines, and remote power grids can be interconnected.

Claims (1)

The invention has a terminal substation for connecting - to a distant alternating current power transmission, containing two power transformers with a series connection of secondary windings, with This one of the transformers is made with a transformation ratio K, -KD, and the other, the secondary winding of which is shunted by reactance X}, is made with a transformation ratio TO,  +213. Kb d J5 20 25 35  , where K is the total transformation ratio of the circuit; B, D - parameters of the four-port network of the power transmission scheme, The primary windings of the transformers are connected to the power transmission, characterized in that, in order to limit the overvoltages on the neutral of the primary winding of the shunt transformer, an additional reactance is included in the circuit of this winding, Y Y Xti X}   With T -YI where A, C are the parameters of a two-port network of a power transmission circuit; Xj, is the resistance of the dissipation of the primary winding of a transformer with a shunting winding; X, is the resistance to dissipation of its secondary winding.