SU114366A1 - Device for automatically switching on high voltage distribution network sections - Google Patents

Description

The subject of the invention is a device for automating high-voltage distribution networks that provides uninterrupted power supply to consumers over a network of any circuit, including those designed without taking into account their automation.

The proposed device provides selective disconnection of a damaged section of a high-voltage power distribution network that is powered through automatic circuit breakers installed at feeding points, equipped with automatic reclosing (AR) and having disconnectors connected in line and power switches mounted on transformer substations connected to it .

This selective disconnection is achieved as a result of the use of auxiliary, normally open power switches at each transformer substation, connected through fuses in parallel with the working disconnectors and power switches and automatically alternately switched on from transformers of the voltage at transformer substations as a result of activation of the automatic reclosing device at the feeding points.

FIG. 1 shows a distribution line equipped with a previous device; FIG. 2 (AB) - the use of the proposed device; FIG. 3 and FIG. 4 - schematic diagrams of automatic switching.

Pa figs. Figure 1 shows an example of a simple distribution line of a looped circuit, supported at its ends by two power sources (distribution substations) or the same power source. Both ends of the line are equipped with the usual automatic reclosing. In the middle, if possible, at the current separation point, the linp is normally disconnected by disconnectors (in this example, at substation TP-6). Power switches 1 are installed in series with disconnectors in transformer substations TP-1-GYa- / 5, which are switched on under normal operating conditions.

No. 114366-2 -

In addition to the main working three-pole disconnectors and power switches, all TP substations have two normally open power switches 2, 3, each of which bypasses a working power switch. These shunt switches are adapted for automatic switching on. PC high voltage fuses are installed in series with them. FIG. Figure 1 shows power transformers Tp and voltage transformers Tn, from which power is supplied to the operational circuits of the automation.

The automation takes place in the following order:

1) If any part of the line is damaged, the circuit breaker on the power supply under the action of overcurrent protection is turned off, and thus all the trans | Sfors of the TP of this half loop are turned off.

2) Under the action of a minimum voltage relay with a mechanical time delay, the working power switches in all substations of the semi-loop are automatically disconnected from the mechanical impulse. In order to avoid false actions of automatics in case of system failures, the time delay of these relays / should be higher than the time delay of the system protection by one selective step.

3) Then all the substations are switched on alternately at the jC of the two ends of the line, both from the side of the power source and from the point of the normal half-loop of the current loop, through automatic operations. At the same time, their action on the side of the normal current section begins somewhat earlier than on the side of the power source, since at the substation at the point of the current section there is a voltage from the voltage transformer.

a) The action of automatics from the side of the normal current divide

After a minimum time (0.1–0.2 sec.) After the occurrence of voltage from the voltage transformer Tn in the operational circuit of the automation at the transformer substation at the line’s current separation point (in this case, TI7-6), the bypass power switches are alternately turned on switch 3 and then switch 2.

Following this, with the same additional time delay (0.1–0.2 sec.), The bypass power switches 5 and 2 in the same sequence of substation automatics (in this TP-5) follow in turn in the same sequence. Such alternate switching on of the substations will occur until the damaged part of the line is turned on, as a result of which the I / C fuse-links in the circuit of the bypass disconnectors are blown; on this, the action of automatics from the side of the normal current separation ceases.

The selectivity is ensured by the fact that for the short circuit 31 there is a single PC fuse, and in all previously switched on TP substations by this time two I / C fuses are connected in parallel (via power switches 2 and 3); all fuse inserts are taken at the same rated current. This current must be equal to the maximum load of the line in case of emergency ren: or its operation.

b) The action of automation from the power source

Under the action of AR, a switch is turned on at the end of the looper at the power source. In this case, the time delay of the automatic reclosing should be one step higher than the effect of the undervoltage relay with mechanical time delay for disconnecting the working power switches at transformer substations.

The further action of the automatics of this direction is analogous to the action of the automatics from the side of the normal current separation. It consists in alternately turning on shunt power switches at all substations located between the power source and the damaged part of the line, and ends with the I / C fuse-links firing when the damaged part of the line is turned on from its second end. Alternatingly turning on the shunt power switches in the course of the action of the automation from the reverse power supply source, which preceded the action of the automation from the holes. the current section, i.e., first, the power switch 2 is turned on, and then the power switch 3.

Thus, the detection and localization of the line damage site and the restoration of power supply to all consumers are automatically performed.

The duty personnel of the network area, after receiving a television signal about the effect of the automatic reclosing on the power source, should make a reverse turn on of the working power switches at all substations of the emergency half of the line and turn off the shunt power switches: 2 and 5.

The advantages of the scheme under consideration are the possibility of transferring the point of separation of a two-way power line from one substation to another, as well as the possibility of applying the scheme to a one-way power line. In the run: the latter case, the recovery of pitains occurs only at substations from the power source to the damaged section of the line. The power supply to the substations of the transformer substation is restored only after the repair of the damaged section, with the exception of the occurrence of self-eliminating damage, when the pit recovery} takes place on all substations of the line.

The number of substations powered by the distribution line is not limited to automation.

Shown in FIG. Figure 1 shows the simplest distribution line as an example to clarify the basic principle of the proposed network automation. The use of this scheme is possible for any multipath and complex network with many connections. In these cases, the restoration of the power supply to consumers during the localization of the emergency mode is automatically provided, in addition to the supply end, not from one normal network current gap, but simultaneously from several, depending on their presence in the circuit.

FIG. 2, the application of this scheme is proved: for a substation TP for one transformer (aj, for a substation for two transformers (b) and for a substation for two transformers when installed on the low voltage side of the device for automatically switching the load from one transformer to another (c).

A low-voltage network can be made according to any open circuit, for example, a circuit that provides power to trunk lines from two adjacent transformer substations, with a connecting point between them, in which the line is open under normal conditions. In the case of multipath high-voltage network construction, a low-voltage low-voltage circuit is allowed, and the cross-links of which are fuses with inserts designed to burn out at certain points for the low-voltage network section, which separates the low-voltage network from one or another section of high voltage network during its emergency operation.

- 3 -L 114366

No. 114366-4 -

The secondary switching circuit is shown in FIG. 3 and 4. Power switches 2 and 3 (Fig. 1) are supplied with switching-on electromagnetic coils of conventional factory manufacture, embedded in their drives. After switching the working group at the actuator from the position of "disconnecting to position" of switching on, these switches from the disconnecting devices turn into automatic switching devices protected by PC fuses.

The automatic shutdown of the working power switches / after switching off in the event of a breaker on the power supply is provided by means of a pulse from the relay. The minimum voltage RH with mechanical time delay is by means of a clock mechanism that does not require operating current (Fig. 3 and 4).

In the presence of voltage, the electromagnet coil is wrapped around the operating current, as a result of which the load switch is held in the COMPLETE position. If the voltage disappears, the clock mechanism starts working, which is triggered after a set period of time. The relay possesses a rather longer time delay, adjustable within certain limits, and it provides a reliable return to the initial position, which prevents a false shutdown in the event of an accident in the system, accompanied by a deep voltage fit in the networks.

Equipped with such a device, the layout of the electrical network of any configuration by the installer is named: “Automatic self-assembling network diagram.

The circuit diagram of switching is shown in FIG. 3. Two time relays P on this circuit are provided for the corresponding delay in switching on the power switches depending on the end from which the network automatics operates.

Time relays can be excluded from the circuit and replaced by ohmic or inductive resistors chosen by calculation. Such a simpler, therefore, preferred scheme is shown in FIG. 4. Here, a delay in the mutual ordering of switching power switches 2 and 3 is necessary because of the slow action of the electromagnetic coil, which gives a mechanical impulse to turn on the power switches due to a decrease in voltage at its terminals.

Subject invention

A device for automatically switching on sections of a high-voltage distribution network that is powered from one or two sides through automatic switches installed at feeding points equipped with automatic reclosing auto-switch and equipped with transformer substations connected to it and having disconnectors and switches in-line power, characterized in that, in order to selectively disable the damaged area during a short circuit on the line, second substation breaker and disconnector parallel power fuses included through normally open auxiliary power switches are automatically alternately having from transformer voltage in transformer substations resulting actuation reclosure on nutrient paragraphs.

fcf4- - r®

I fI X4-4-J

s-ash

-

- t V

-. ,, L. (J

rJ-jlt-j

.

144 f

Si

 K feiy

one

 S

,

S

IT