Feeding points of devices of automatics and telemechanics

Feeding points of devices of automatics and telemechanics

Ways of a food of high-voltage lines СЦБ (BJ1 СЦБ) . A food of devices of automatics and telemechanics on stages and small stations is carried out from VL СЦБ. Earlier pressure of these lines was 6 or 10 кВ, last years — 10 sq.

For a food of a high-voltage line of automatic lock-out as the basic and reserve sources of the electric power use existing power supply systems, power stations and substations or high-voltage transmission lines with joining to switching centres high or a low voltage. To a reserve food of devices of automatics and telemechanics in the absence of existing points of a food apply a diesel engine-generating of installation which mount in separate buildings or premises.

The electrical supply of high-voltage lines of automatic lock-out is carried out through points of a food which arrange in places of reception of the electric power and equip with corresponding devices avomati and switching. In each direction of a high-voltage line a food arrives through an independent feeder. A food of two directions through one feeder is supposed only on reserve points of a food at the mixed power supply system.

For an exception of electric communication of VL СЦБ with other lines connected to the general tyres of substation, feeders connect to switching centres through the separate power transformer or through two transformers one of which is lowering, and another — raising.

It is possible to attach to point of a food of VL СЦБ one of next ways.

Pressure of feeding point 220 In raises to 10 кВ (fig. 263,). On the electrified sites a food on this way is carried out from tyres of own needs of traction substation 0,22 sq.

On feeding point use available pressure 10 кВ (fig. 263,), and VL СЦБ connect through isolating transformers IT (10/10 кВ). Probably direct connection of VL СЦБ to tyres pressure 10 кВ under a condition if lines of other consumers are not connected to them.

On feeding point pressure 6 кВ raises to 10 кВ (fig. 263,). As the industry does not let out such transformers VL СЦБ connect to tyres 6/10 кВ through consistently connected two transformers: one lowering 6/0,4 and other raising 0,4/10 sq. This scheme apply at connection of VL СЦБ to transformer substation.

Feeding points in which pressure for a food of VL СЦБ does not change, name distributive (fig. 263 see,), and points in which this pressure raises or goes down, name transformer (fig. 263, айв see).

High-voltage line СЦБ can receive a food from transformers of own needs of traction or other substations from a low voltage of power stations through raising mast substations of open type or raising substations of the closed type, from switching centres of power stations, traction substations of different function pressure 10 sq.

Principal views of protection and automatics of points of a food . Quickly to restore supply of electricity in high-voltage line СЦБ or to disconnect the damaged site of a line and to provide the alarm system about character the damages feeding points equip with protection and automatics devices.


The feeders feeding devices STSB on system of an alternating current, have: as much as possible-tokovuju protection operating on switching-off; the protection of the minimum pressure operating on switching-off; protection against single-phase short circuits on the earth operating on the alarm system about infringement of a normal operating mode or on switching-off.

Along with protection schemes feeding points equip: automatic repeated inclusion of a high-voltage line (АПВ) and automatic inclusion of reserve points (АВР); remote control of feeders from a premise with the constant personnel on duty; telecontrol (on traction substations) and the alarm system of position of feeding switches, their emergency switching-off, short circuits on the earth, pressure disappearances on tyres of point of a food, action АПВ and АВР; automatic start-up of reserve converters of frequency in points of a reserve food of a high-voltage line frequency of 75 Hz at electrodraught of an alternating current; automatic sectioning of a line in sectioning points. Alarm system devices establish indoors, whence carry out remote control.

The feeders intended for a food of devices STSB on the mixed power supply system, have: as much as possible-tokovuju protection operating on switching-off; the protection of the minimum pressure operating on switching-off; protection against single-phase short circuits on the earth; operating on a signal; the alarm system of emergency switching-off of feeders and short circuit on the earth. Alarm system devices establish indoors with the constant personnel on duty.

The points of sectioning arranged in a place of a cut of a high-voltage line, supplement: device AVR including the feeding switch at disappearance of pressure on one of adjoining sites of a line; as much as possible-tokovoj protection which is disconnecting the damaged site of a line; the alarm system of position of the section switch, protection and automatics action. Alarm system devices place in a premise in which constantly there is a personnel on duty.

The operative current is necessary for operation of devices of relay protection and automatics. Operative name a current proceeding in secondary chains of relay protection and automatics, and also in alarm system and management chains. Apply two variants of power supply circuits of devices of relay protection and automatics — on an operative constant and operative alternating current.

The schemes working on a constant operative current, use on the feeding points equipped for own needs with storage batteries by pressure 110 or 220 In and receiving 110 or 220 food from traction substations.

The schemes working on a variable operative current, apply when automatics and telemechanics devices eat from transformer substations and power stations. As sources of a variable operative current transformers of a current and pressure transformers, and also power transformers serve. Air and cable transmission lines, and also the equipment included in a line, constantly are under a high voltage. During operation of devices the normal mode of their work can be broken. The most part of infringements occurs owing to междуфазных short circuits, isolation damage разъединителей, transformers which lead to short circuits between phases or a phase and the earth, switching-off of pressure from tyres of points of a food. That in such cases to warn equipment damage, a site which further work is inadmissible, it is automatically disconnected. At infringement of a normal operating mode and damages when immediate switching-off of a line is not required, automatic giving of the signal, informing attendants about damage on a line is provided. Switching-off of the damaged site of a line or signal giving is carried out by means of relay protection.

Relay protection is carried out by the special devices consisting of the relay and other devices which at damage of a site or infringement of a normal operating mode of any element of electroinstallation automatically disconnect the damaged site or give a signal to the personnel on duty about infringement of a normal operating mode of relay protection

As much as possible-tokovaja protection is intended for fast automatic switching-off of a high-voltage line from food point when the current in a line exceeds some in advance established value. At short circuit on a line or isolation breakdown in the linear equipment leading to short circuit between phases, in a damage place there is an electric arch with high temperature which destroys metal details of the equipment and insulators. In most cases failure can be prevented fast switching-off of the damaged site. In a high-voltage line to use for protection fuses it is impossible because of small currents of short circuit which lines owing to the big resistance slightly exceed the nominal.

Protection against single-phase short circuits on the earth automatically gives a signal to the personnel on duty at short circuit of one of phases on the earth.

High-voltage line СЦБ is a line with the isolated neutral, therefore single-phase short circuit on the earth in such line is accompanied by following phenomena: pressure of the damaged phase concerning the earth to equally zero; pressure of the intact phases concerning the earth increase in 1,73 times and become equal междуфазным; междуфазные pressure do not change; a current of single-phase short circuit on the earth on each 100 km of an air-line at pressure 10 кВ about 2,5 A.Tak kak at single-phase short circuit on the earth междуфазные pressure do not change, work of devices STSB is not broken, therefore immediate switching-off of a line it is not required. However increase of pressure of the intact phases concerning the earth can lead to isolation breakdown on serviceable phases. Besides, asymmetry of pressure breaks normal work of the communication lines passing in parallel In L СЦБ. Therefore long work of a high-voltage line at short circuit of one phase on the earth is inadmissible, it is necessary to take measures on damage liquidation.

Protection of the minimum pressure automatically disconnects a high-voltage line from tyres of point of a food in cases full отключенья pressure or voltage reductions to 50 % nominal and more low. At switching-off of pressure from tyres of point of a food schemes provide automatic giving of pressure in a line of automatic lock-out from the opposite end of a line — from other power supply.
If not to disconnect from a line food point from which tyres pressure all consumers of this substation also will receive a food through a high-voltage line is disconnected. It will lead to the big overloads and pressure losses in a line that will cause operation maximum токовой protection on reserve point or infringement of work of devices STSB because of the lowered pressure of a food.

Automatics application on food points in many cases gives the chance to restore so quickly pressure giving in a line at protection operation that infringement of normal work of devices STSB does not occur.

Operating experience of high-voltage lines of automatic lock-out has shown that short circuits on lines arise because of the lightning discharges causing breakdown of insulators, short circuit of wires of different phases by birds, схлестывания wires, hits on wires of branches at a strong wind and etc. the Most part of similar short circuits has short-term character as the reasons which have caused them withdraw, and arisen in a place of short circuit the arch dies away at operation of as much as possible-tokovoj protection.

In cable networks short circuits occur on transformer substations owing to breakdown of isolation of assemblages or high voltage safety locks more often. The considerable part of these overlappings has also short-term character. Therefore if protection operates quickly enough the arch which has resulted short-term short circuit, has not time to destroy insulators or to burn through wires, and the high-voltage line can be again put into operation without immediate repair.

For fast repeated inclusion of automatically disconnected line use devices with which help the disconnected line gets into gear again automatically. Automatic switching-off of a line and the following immediate behind it its automatic inclusion after operation as much as possible-tokovoj protection carries the name of automatic repeated inclusion (АПВ).

On lines of VL СЦБ apply devices APV three-phase unitary action with automatic return, i.e. such which include a line repeatedly only once, time of repeated inclusion should be no more than 0,1 with. Three phases and if the line is disconnected again by protection devices APV are disconnected also the second time Simultaneously join do not operate. However after device APV operation are automatically prepared for the next cycle of work. Devices APV are carried out by means of relay schemes or mechanical adaptations.

For maintenance of reliable power supply of devices STSB a high-voltage line divide into separate sites, each of which has a bilateral food. Normally high-voltage line eats from one end from the basic point. The point of a food located on other end of a line, is disconnected and is reserve. At deenergizing of power supplies from the basic point of a shoulder of a food the reserve point of other end of a shoulder of a food is automatically connected. The break between switching-off of pressure of the basic point of a food and connection of pressure reserve should not exceed 1,3 with. Connection of points of a food to VL СЦБ and VL ПЭ should be identical on a phase.

Devices of automatic inclusion of a reserve (АВР) automatically include reserve point of a food at switching-off of the basic point or the site of a line adjoining to reserve point. Device AVR apply on low voltage lines postovelekt-richeskoj centralisation. In posts of electric centralisation two feeders of the low voltage, one of which basic, and another — reserve are connected. From food points both feeders always are energised. Them attach to tyres of an introduction board of a post of centralisation through контакторы which automatically include a reserve feeder at pressure disappearance in the basic feeder.

Devices of control and management of power supplies devices.

Grounding signalling devices, the semi-conductor relay of pressure of type РНП, the automatic switch concern them «Day — night» АДМ and the phasing device of type ФУ-1.

Grounding signalling devices are intended for continuous control over resistance of isolation of operating devices STSB. Signalling devices allow to measure resistance of isolation of controllable networks concerning the earth and rather each other. Let out five types of signalling devices: I, II, С31, С32 and СЗЗ. By means of a signalling device of type I supervise isolation of electric networks constant and an alternating current pressure 220 and 24 In, and a signalling device of type II — isolation of electric networks of a direct current by pressure 160, 24 In and an alternating current pressure 220, 24 V.Signalizatorami of types С31, С32 and СЗЗ simultaneously supervise isolation of six electric networks which do not have galvanic communication: a direct current pressure 220, 60 and 24 In; an alternating current pressure 220, 24 and 12 V.Signalizatory eat from a network of an alternating current frequency of 50 Hz, a voltage of 220 V. At resistance of isolation below the established standard value the grounding signalling device should submit acoustic and optical signals.

The semi-conductor relay of pressure of type РНД serves for control of a network of an alternating current with rated voltage 110, 220 both 380 In and the storage battery pressure 24 Century

At work from a single-phase network of an alternating current of relay RNP together with the relay of type АШ2-1800 carries out functions of the emergency relay with high factor of return. For pressure check in a three-phase network establish three relays RNP and one relay of type АШ2-1800. One relay RNP others use as a threshold element and a direct current source in a single-phase network, and two — as key elements in the consecutive scheme of coincidence. At work from relay RNP direct current together with relay NMSH apply to management of a mode of a charge of the storage battery, and also for control of a voltage reduction of the battery to is minimum admissible level.

Relay RNP is the contactless gauge of pressure of a food of the electromagnetic relay with rated voltage 24 In and resistance of a winding not less than 900 Ohm. It can be used independently as a threshold key element on pressure to 24 In and a current to 25 мА. Relay RNP has two stable and independently regulated thresholds of overturning: a straight line — pressure of an attraction and return — pressure отпускания. The return factor (отпускания to pressure of an attraction) can be regulated the pressure relation largely and to reach thus high value (to 0,97).

The Automatic switch «Day — night» АДН apply to diet switching светофорных lamps depending on natural light exposure. Switch ADN allows to improve visibility of signal lights, to increase a resource светофорных lamps and to reduce the expense of the electric power at night. It use together with the small-sized plug relay of type НМШ2-4000 on 24 V.Perekljuchatel establish in a relay premise of post ЭЦ on an internal frame of a window.

Automatic switch "Day-night" ADN represents the trigger on two transistors VI and V2 different conductivity (VI type р — п — р, a V2 type п — р—). The trigger condition when both transistors are opened also the BOTTOM relay alive, corresponds to a day diet светофорных lamps and when transistors VI, V2 are closed also the relay of the BOTTOM without a current — to a night diet светофорных lamps. In the autoswitch scheme use сернистокадмиевые photoresistors of type ФСК-Г1 which possess property to change the conductivity under the influence of light — a so-called internal photoeffect.

The phasing device of type ФУ-1 is the contactless device defining a phase of one signal of an alternating current concerning another. On a device exit include two switching relays of the direct current one of which works at conformity of phases of signals, and another — at overturning of a phase of one of signals. The phasing device is placed in a casing of the relay of type НМШ.

Necessity of check of a phase arises first of all in devices of power supplies of rail chains of an alternating current frequency of 25 Hz. Travelling transformers of rail chains receive a food from the travelling converter of frequency, and local elements of travelling relays of type ДСШ — from the separate local converter. Phases of pressure on an exit of converters of frequency ПЧ50/25 at inclusion can change on 180 ° rather each other. However for work of travelling relays pressure on travelling elements, and thereby and in rail chains should be identical on a phase with pressure on local elements.

Principle of work of the phasing device use in the decoder of a difference of frequencies of two сигалов in supply equipments of station rail chains of an alternating current with the raised noise immunity. In them rail chains work on the frequency which is distinct from frequency of a network. In this case the control relays included on exit ФУ-1, receive serially food impulses, and for the period of an interval keep якори drawn at the expense of delay.