SU636549A1

SU636549A1 - Arrangement for shaping square-wave pulses of three-phase system maximum current

Info

Publication number: SU636549A1
Application number: SU772495159A
Authority: SU
Inventors: Виктор Анатольевич Аллилуев; Александр Сергеевич Засыпкин
Original assignee: Новочеркасский Ордена Трудового Красного Знамени Политехнический Институт Им.С.Орджоникидзе
Priority date: 1977-06-08
Filing date: 1977-06-08
Publication date: 1978-12-05

Description

1one

Изобретение относитс к области релейной защиты, в частности, может использоватьс в односистемных дифференциально-фазных защитах с контролем величин токов.The invention relates to the field of relay protection, in particular, can be used in single-system differential-phase protection with control of current values.

Известны устройства дл формировани пр моугольных импульсов, содержание фильтр симметричных составл ющих токов, трансформаторы и высокочастотный приемопередатчик.Devices for generating square pulses, the content of a filter of symmetrical component currents, transformers, and a high-frequency transceiver are known.

Недостаток устройства заключаетс в том, что амплитуда пр моугольных импульсов в цепи модул тора высокочастотного приемопередатчика не зависит от величин входных токов устройства l1 .The drawback of the device is that the amplitude of the rectangular pulses in the modulator circuit of the high-frequency transceiver does not depend on the input currents of the device l1.

Наиболее близким техническим решением к данному изобретению вл етс устройство максиселектора, содержащее трансформаторы тока, нагруженные на резисторы и подключенные к выпр мительным мостам со сглаживающими конденсаторами , логический блок ИЛИThe closest technical solution to this invention is a max-selector device containing current transformers loaded on resistors and connected to rectifying bridges with smoothing capacitors, logic block OR

ННедостатком известного устройства максиселектора вл етс то, 1то выходное напр жение его лишь пропорционально величине максимального тока трехфазной системы, а информаци о фазе тока не сохран етс .The disadvantage of the known device of the max-selector is that its output voltage is only proportional to the maximum current of the three-phase system, and information about the phase of the current is not saved.

Целью изобретени вл етс увеличение объема информации о максимальном токе трехфазной системы.The aim of the invention is to increase the information about the maximum current of a three-phase system.

Цель достигаетс тем, что в устройстве дл формировани пр моугольных импульсов от максимального тока трехфасной системы, содержащем трансфор маторы тока, нагруженные на резисторы, выпр мите.пьные мосты со сглаживающими конденсаторами, логический блок ИЛИ, между выходами выпр мительных мостов и входами логического блока ИЛИ включены полупроводниковые прерыватели, запирающие входы которых The goal is achieved by the fact that in the device for forming rectangular pulses from the maximum current of a three-phase system containing current transformers loaded on resistors, rectifying direct bridges with smoothing capacitors are a logical block OR, between the outputs of the rectifying bridges and the inputs of the logical block OR semiconductor interrupters are included, locking the inputs of which

5 через диоды подключены ко вторичным обмоткам трансформаторов тока, один из входов блока сравнени подключен к выходу логического блока ИЛИ, между другим входом блока сравнени 5 through the diodes connected to the secondary windings of current transformers, one of the inputs of the comparison unit is connected to the output of the logic block OR, between the other input of the comparison unit

0 и выходами выпр мительных мостов вк.)1ючен второй логический блок ИЛИ,0 and rectifier bridges exits VK.) 1Second logical block OR,

Такое устройство позвол ет получить пр моугольные импульсы от максимального тока трехфазной системы с Such a device allows to obtain rectangular pulses from the maximum current of a three-phase system with

5 амплитудой, пропорциональной величине максимального тока, и длительностью, равной длительности положительной полуволны указанного тока.5 amplitude proportional to the maximum current, and the duration equal to the duration of the positive half-wave of the specified current.

На чертеже изображена блок-схема The drawing shows a block diagram

Claims

0 a device for forming square pulses from the maximum current of a three-phase system, made in accordance with the present invention. The device contains a current transformer 1,2 and 3, loaded on resistors 4, 5 and b, the voltage from which is given to the inputs of rectifier bridge 7.8 and 9 with smoothing capacitors 10, 11 and 12, Semiconductor interrupters 13, 14 and 15 locking through the diodes 16, 17 and 18 are connected to the secondary windings of current transformers, the line inputs are connected to the outputs of the rectifying bridges 7, 8 and 9, and the outputs are connected to the inputs of one of the logical blocks OR 19 The inputs of the other logical block OR 20 are connected to Exit bridges mkdelnzh bridges 7, 8 and 9, and you x The unit 19 is connected to the input 21 of the comparison unit 22. The input 23 of the comparison unit 22 is connected to the output of the ILIC 20 block. The output of the device is the output of the comparison block 22. The device operates as follows. The voltages allocated to the resistors 4, 5 and b and proportional to the phase four currents of the three-phase system, through rectifying bridges 7, 8 and 9 and the capacitors 10, 11 and 12 are fed to the semiconductor breakers 13, 14 and 15, locked by voltages, arriving from the secondary windings of current transformers 1, 2 and 3 through diodes 16, 17 and 18, at a positive half-wave of blocking voltages, the voltages at the outputs of the interrupters 13, 14, and 15 are equal to the input voltages at a negative half-wave, at the outputs of the interrupters are zero. During the course of the logical block OR 19, the voltage is taken, the instantaneous value of which at each moment is equal to the largest of the voltages on the interrupters. In the course of the logical block OR 20, a voltage equal to the largest of the output voltages of the rectifying bridges 7, 8 and 9 is allocated. Comparison block 22 has the property that, when equal to {voltage at inputs 21 and 24, voltage to the output of block 22 is equal to the voltage at input 21, and if the voltage at input 21 is less than the voltage at input 23, the output voltage of the comparison block 22 is equal to kul. Thus, at the output of the device, rectangular pulses are emitted with an amplitude proportional to the maximum current of the three-phase system and a duration equal to the positive half-wave duration of the indicated current. The invention The device for the formation of rectangular pulses from the maximum current of a three-phase system, containing current transformers, loaded on resistors, and connected to rectifier bridges with smoothing capacitors, logic unit. OR, in order to increase the amount of information about the maximum current of a three-phase system, a comparison unit, a second logical block OR, three semiconductor switches and three diodes are added to the device / while the comparison block inputs are connected to jc outputs of both logical blocks OR , cBOMNffl semiconductor breakers with linear inputs are connected to the rectifier outputs of Echo bridges, power inputs through the diodes are connected to the secondary windings of current transformers, the outputs of the semiconductor interrupts s are connected to inputs of a OR logineskih blocks, the inputs of another OR logic block connected to the outputs of rectifying bridge. Sources of information taken into account in the examination: 1, USSR Copyright Certificate 288106 H 02 H 3/22, 1968.

2. Schneerson E.M., Semiconductor resistance relays, Energy, M., 1975, p.48.

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