SU1309147A2 - Device for single-phase automatic reclosing of electric power line - Google Patents

Abstract

This invention relates to electrical engineering, in particular, to devices for relay protection and automation. The purpose of the invention is to reduce the volume of emergency response measures in processes caused by damage to power lines under conditions of a low probability of successful completion of a single-phase automatic reclosing power line. In modes in which the power flow over power is less than the setpoint set by 14, the signal at the output of amplifier 11 is absent. In modes in which the power flow exceeds the setpoint, a positive signal appears at the output of the comparator unit, which through diode 12 enters the input of the amplifier 11, after amplification enters the input of the unit 5 and switches the controlled keys. Signal about the appearance of short-circuit from block 1 enters block 2, which disconnects the damaged phase. Signal about the appearance of short-circuit It does not arrive at the time delay unit 3 and at the re-energization unit 4 of the damaged phase, but through the disconnecting key in the closed state it is applied to the emergency control system and through the delay unit 7 to the three-phase disconnection unit. The device thus performs, depending on the current load of the line, automatic blocking of the AADO, and the magnitude of the power setpoint takes into account I (L co ω with N "i 4

Description

circuit features of the line, as well as the value of the mathematical expectation of success of the UAPV. The essential feature is also the preservation of the principle

The invention relates to electrical engineering, in particular, to devices for relay protection and linear automation and is an improvement of the known device according to the author. St. No. 1188633.

The aim of the invention is to reduce the volume of emergency response measures in the processes caused by damage to power lines under conditions of a low probability of successful completion of the PAVA.

For each mode, there is a certain level of likelihood of successful completion of a QADD. If the probability decreases below this level, it is advisable to abandon the OAPV, and to take emergency measures in the power system without changing the delay, directly on the fact of damage to the line.

Equivalent can be considered such solutions associated with the use or rejection of the use of automatic reclosing, in which the total volume of control actions of emergency control automation are equal. Let / probability of damage to overhead lines, the probability of successful completion of the cycle of a PLLV,} - qyy - the probability of unsuccessful completion of the cycle of a pvr and let for some initial mode: Pj - the volume of control actions with successful PAVA impacts in case of unsuccessful OAPV and RZ - the volume of control actions in the absence of automation of OAPV

() The limit of expediency of use

Automation system in this mode is determined by the condition

R.L, + P, (D- Ay) PjA

from where

 .

/) KPUT. -

Since the volume of control actions is functionally dependent on the loading of Pe connection in the initial steady state, the boundary condition for the expediency of using an OAPV can be represented as

 f (- - IR1.

-)

pa late shutdown of intact phases by the time of the issuance of a signal to the action of emergency control. 1 il.

When there is a high likelihood of successful completion of the UAPW (, 4-0,5)

the value of Pj exceeds the communication capacity, in connection with which IADS

It is advisable to carry out in all modes of loading. However, for small ratios x, the existence of regimes with FO PO to () and 7 is possible in which the use of a known device leads to the redundancy of emergency control actions.

The drawing shows a block diagram of the proposed device.

The damaged phase 1 voter is associated with the disabled unit 2

phases. After a certain period of time after the disconnection of the damaged phase, specified by the exposure block 3, the block 4 re-activates the damaged phase. In case of unsuccessful OAPV

through block 5, a command is sent to block 6 to disconnect the three phases, and this command is transmitted with a delay determined by delay block 7. The magnitude of the delay is determined automatically in the nonlinear converter 8, based on the information received through the delay unit 9 from the unit 10 for measuring the line power.

In addition, the input from the transfer unit 5 to the three phases is disconnected through the amplifier 11 and the diode 12 is given a signal from the comparison unit 13, the inputs of which receive signals from the outputs of the set point 14 and the delay unit 9.

The setpoint unit 14 is a constant voltage source with a discretely adjustable potentiometric output. The voltage at the output of block 14 is proportional to the scale of the setpoint set power flow through the line. The magnitude of the power setpoint is determined by preliminary calculations of the necessary volumes of application of emergency control equipment in transients caused by short-circuits. on line. Calculations are made taking into account the magnitude of the mathematical expectation of the accuracy of a PELV for this VL, as well as taking into account the scheme of its inclusion. The setpoint is set in block 14 manually using a switch or automatically from a computer through an appropriate signal converter. Comparison unit 13 generates a signal proportional to the difference of the input signals at the output. The block can be executed, for example, in the form of an operational amplifier with two inputs, to which the compared signals of opposite signs are supplied.

The additional units are connected to the unit 5 for switching off the three phases and to the unit 9 lagging. Block 5 is a combination of two control keys: short and open. The delay unit 9, which provides the input signal tune-up of the unit 8 from power fluctuations during the pivotal pause, realizes the function U ,,. . AT

In the case of an analog version, the block can be made in the form of an op amp with a resistor at the input and in parallel with the resistor and capacitance in feedback.

The device works as follows.

In modes in which the power flow over power transmission is less than the setpoint set by block 14, which indicates the expediency of the OAPV automation, the signal at the output of amplifier 11 is absent and the device works as known. In modes in which the power flow exceeds the setpoint, a positive signal appears at the output of the comparator unit, which through diode 12 enters the input of the amplifier 11 and, after amplification, enters the input of the unit 5 and switches the controlled keys. In this state of the device circuit, the signal about the appearance of a short circuit. from block 1 enters block 2, which disconnects the damaged phase.

0

In connection with the open state of the closing key, the signal about the occurrence of a short circuit. It does not arrive at the time delay unit 3 and at the re-activation of the damaged phase 4, but through the disconnecting key which is in the closed state, it is applied to the emergency control automation and through the delay unit 7 to the 3-phase disconnect switch b.

Depending on the current load of the line, the proposed device thus performs automatic blocking of the AADO, and the power setting takes into account the circuit features of the line, as well as the average waiting time of the AADO.

In addition, when blocking automatic automation, the principle of delayed switching off of intact phases with respect to the moment of issuing a signal to the emergency control automation, which minimizes the required amount of its application, is preserved.

Claims (1)

Invention Formula The device of single-phase automatic restarting of the power line (OAPV) by bus. St. No. 1498633, characterized in that, in order to reduce the volume of emergency response measures in the processes caused by damage to power lines under conditions of a low probability of successful completion of the PAVA, it is equipped with a setting block, a comparison unit, a diode and an amplifier, and the output The setpoint unit is connected to the first input of the comparator unit, the second input of which is connected to the output of the delay unit, the output of the comparator unit through the diode and the amplifier is connected to the input of the transfer unit for switching off three phases.