SU725144A2 - Arrangement for limiting short-circuiting current at high-voltage substation - Google Patents

Description

resistances are matched with one basis value).

In the normal operation mode and LRI three-phase short-circuit, on the side of the convolving voltage -.block 1, the IB windings of the transformatormal 3, connected in a triangle, almost all flow through the reactors 10. The presence of a common heart (ka // does not affect the magnitude of the currents in the reactors 10, since the currents are equal in magnitude. And yedVINutes by 120 °. The total flow in the o6ui, eM core // from these currents is zero. As a result, additional losses (B Reactors 10 nswelsh.

. At the two-phase short circuit on the side of the high voltage of the transformer 3, the fault current flows in two O | mbot (ka triangle, or the fact that the currents in the windings p, aiBiHbi in size and dash (vololozhny through planting low-free reactors 10. The flow in the common core // peaiKTOpoiB 10 from these currents is equal to 0. The flow of damage currents during three- and two-phase short circuits through dizkoomnye reactors 10 contributes to maintaining stability.

When a single-phase short circuit on the high voltage side of transformer 3, the current IB to the winding 8 of the damaged phase triangle divides into parts: / s it flows in the reactor 10 and / s in the reactor 9. The current in the reactor 10 creates a flow in the heart 11, under the effect of which in two other reactors 10 generates a current equal to / 3 of the current in the winding 5 of the damaged phase. This current is closed in reactors 9 parallel to reactors 10 and does not pass into the windings of 8 healthy phases.

In the case of a single phase short circuit, short circuits are

Included are reactors 9 with a large resistance, which limits the short circuit current. The current of a single-phase short circuit is L

ty s

 + ,,,

where and - phase voltage; ,

x - parameters of the transformer; x /, generator parameters;

 - resistance of the reactor 10; HD - the resistance of the reactor 9.

The use of the proposed device allows to limit the current of a single-phase short circuit by 1.8-2.5 times IB compared with the currents of a three-phase short circuit, which will increase the reliability of the power system and give a significant economic effect.

Claims (1)

Invention Formula Device for g | | Razchivni - short-circuit current at a high-voltage substation by author. av No. 595826, which is based on the fact that, with a gap to reduce losses and increase stability, it is equipped with three reactors M1i, having a common ferromagnetic core, which are connected to a pair: allele reactors, which are connected in series; | ra. The source of information taken so much attention at examination: I. Copyright certificate № 595826, cl. H 02 H 9/02, 1976.