SU1277278A1 - Method of one-phase automatic reclosing of highest-voltage section in combined a.c.lines - Google Patents

Abstract

The invention relates to power engineering and can be used in the development of automatic reclosing of multi-chain overhead power lines. The purpose of the invention is to increase the re-start efficiency by suppressing the charging arc current. A double chain combined air line connects the starting 1 and receiving 2 systems. High voltage circuit (HV). through line switches 6 and step-up transformers 7 are connected to buses of systems 1 and 2. A low voltage circuit (LV) is connected to systems 1 and 2 via line switches 11, providing the shift between the voltage vectors of HV circuits and NN At the ends of the low voltage circuit, shunt disconnect switches are installed 13. When a fault occurs in the phase of the high voltage circuit, it is turned off by the switches 6. At the same time, knobs 11 disconnect the next low phase of the low voltage circuit, then IsD ts9 s | 00

Description

The bypass switches 13 are turned on in this phase. Decrease in the magnitude of the arc charging currents at a short circuit. on the HV circuit frequency and shunting of the disconnected phase of the low voltage circuit due to a decrease in the magnitude of the electromagnetic component of the arc feed current and VN. Additional shunting of the disconnected phase of the LV circuit at short circuit in the nearest phase of the high voltage circuit in the transmission mode of the mosh mosh; this leads to a decrease in arc feed currents of more than 1.5 times, which lie in the range of self-extinguishing arc currents. 2 Il.

one

The invention relates to electric power industry and can be used in the development of automatic re-activation of multi-circuit combined overhead power lines.

The aim of the invention is to increase the efficiency of re-switching on by suppressing the arc current.

FIG. 1 is a schematic diagram of the double-circuit transmission in FIG. 2 is a replacement circuit for determining the effect of a shunt phase of a lower voltage circuit on arc charging currents during a short circuit (short circuit) on the phase of a higher voltage circuit.

The transmission scheme contains a double-circuit combined overhead line connecting the starting 1 and. reception 2 systems. A higher voltage circuit (HV), formed by phase conductors 3, 4 and 5, is connected through line switches 6 and step-by-step transformers 7 to buses with 1 and 2 sieves. A low voltage circuit (HH) formed by phase wires 8, 9 and 10, using linear switches 11, it is connected to systems 1 and 2 through phase-regulating devices 12, which provide a shift between the voltage vectors of the HV and LV circuits. At the ends of the circuit NN installed shunt switches 13.

In the computational replacement scheme (Fig. 2), which makes it possible to evaluate the efficiency of the clearing of the nearest and emergency phases of the LV circuit at a short circuit. on the HV circuit, accept the following notation:

2

14- inductive resistances of phase conductors 3, 4 and 5 of high voltage circuit

(HF,);

15- capacitive resistance of the emergency phase to earth (X)

1 b - phase resistance of the four-beam reactor replacement circuit (Xrsr);

17- inductive resistances of phase conductors 8, 9 and 10 of the HH circuit

(hf „);

18 is the longitudinal EMF acting in the shunt and disconnected phase of the HH circuit (Y, p;);

19 - mutual induction coefficient between loops; emergency phase of HV circuit - ground and disconnected and shunt phase of HH circuit - ground (M);

20 is the longitudinal emf acting in the emergency phase of the high voltage circuit, determined by the currents in the phases of the high voltage and low voltage circuits adjacent to the systems - 3, 4, 9 and

10 (E „,,.);

21.- longitudinal emf acting in the emergency phase of the HV circuit, determined by the current flowing in the disconnected and bypassed phase of the LV circuit

E „ra) -. ,

Claims (1)

Single-phase automatic re-start, switching on the higher voltage circuit in the power transmission circuit (Fig. 1) is performed as follows. When a fault occurs on phase 5 of the HV circuit, it is turned off by switches 6 at the ends of the line. Simultaneously, switches 11 turn off the phase 10 of the low voltage circuit closest to it, after which the shunt switches 13 are turned on at this phase 10. Reduction of the currents in the arc feed at short-circuit. at the phase of the high voltage circuit and shunting the disconnected phase of the low voltage circuit due to a decrease in the magnitude of the electromagnetic component of the arc feed current. Indeed, in the power transfer mode over VL, the longitudinal emf of YPRM, AND E "p" can be approximately defined as E.R. -J-CijM, .5 + i, M,. ,, -fi, M., M ,.) EPR „(1MMsmo-im,. ,, n.Mg., + where ij, i, ig, Phase wires 3, 4, 8 and 9, respectively, MVW C-1a 8-S Mi-5 4-S - coefficients 8-10 g-10 9-5 8-10 s mutual induction between current loops formed by phase wires and ground E (for example, MD is the coefficient of reciprocal induction between loops, phase 3 - earth and phase 5 - earth). Mutual induction coefficients М М М М М М М N-10 gs s-io Hi-. М (the difference between these coefficients is mutual induction does not exceed 1–4%. Therefore, the E р p ,, Current in the disconnected and shunt phase of the HH circuit induces a longitudinal EMF directed This is opposed to E, p, and as a result, the electromagnet is reduced by the component of the arc charging current at the short circuit phase of the high voltage circuit.After the feed arc is extinguished and before re-switching on, the shunt switches 13 are turned off at the phase 10 and then circuit breakers II and 6 of the 10 and 5 circuits, respectively, of the highest and highest voltage., Additional shunting of the disconnected phase of the LV circuit at short-circuit. in the nearest phase of the high voltage circuit in the transmission mode of high power (large angles), the arc feed currents are reduced by more than 1.5 times, which do not exceed the values of 60-70 A, lie in the range of self-extinguishing arc currents. This increases the efficiency of the proposed method in combined air lines. The claims of the method of single-phase automatic reclosing of the high voltage circuit in combined AC lines, in which, after the occurrence of a single-phase ground fault, the high voltage circuit disconnects the damaged phase and the closest phase of the low voltage circuit and disconnect the phases after extinguishing the arc both circuits, characterized in that, in order to increase the re-start efficiency by suppressing the charging arc current, after disconnecting the phase of the lower voltage circuit audio it is connected at both ends of the line to the ground, and before reclosing disable this phase from the ground. / 17 / .1J 17 FIG. 2