SU585573A2

SU585573A2 - Current filtering relay

Info

Publication number: SU585573A2
Application number: SU762353509A
Authority: SU
Inventors: Валерий Кузьмич Ванин; Алексей Ибрагимович Таджибаев
Original assignee: Ленинградский Ордена Ленина Политехнический Институт Им.М.И.Калинина
Priority date: 1976-04-22
Filing date: 1976-04-22
Publication date: 1977-12-25

Description

Изобретение касаетс автоматизации энергетических систем,The invention relates to the automation of energy systems,

По основному авт. CBJ 5O2439 известен фильтр - реле тока, содержащий преобрзователи входных сигналов, подключенные через фильтр симметричных составл ющих и выпр митель к пороговому элементу.According to the main author. CBJ 5O2439 is a known current filter; it contains input signal converters connected through a balanced component filter and rectifier to a threshold element.

Однако в сет х со значительной несим- метрией в нормальном режиме он срабатывает ложно. Отстройка от несимметрии нор мального режима приводит к чрезмерному загрублению фильтра - реле. В таких сет х известный фильтр - реле не может быть использован в качестве пускового органа релейной защиты,However, in networks with significant asymmetry in normal mode, it works falsely. The detuning from the asymmetry of the normal mode leads to an excessive coarsening of the filter-relay. In such networks, a well-known filter-relay cannot be used as a starting element for relay protection,

Целью изобретени вл етс повышение чувствительности и расщирение функциональных возможностей фильтра - реле тока.The aim of the invention is to increase the sensitivity and enhance the functionality of the filter - current relay.

Это достигаетс тем, что в предложенном фильтре - реле тока между выходом г выпр мител и вторым входом порогового элемента дополнительно включен элемент запаздывани .This is achieved by the fact that in the proposed filter, a current relay between the output of the rectifier and the second input of the threshold element, an additional delay element is included.

На чертеже представлена принципиальна схема предложе шого фильтра - реле The drawing shows a schematic diagram of the proposed filter - relay

тока. Он содержит преобразователи 1,2,3 i входных сигналов, фильтр 4 симметричных составл ющих с коммутатором 5 и многополюсниками 6, 7 и8, выпр митель 9, элемент 10 запаздывани с резисторами 11, 12 и конденсатором 13, пороговый элемент 14.current. It contains 1, 2, 3 i converters of input signals, a filter 4 symmetrical components with a switch 5 and multipoles 6, 7 and 8, a rectifier 9, a delay element 10 with resistors 11, 12 and a capacitor 13, a threshold element 14.

Преобразователи входных сигналов имеют по два выхода, причем напр жение на одном из выходов находитс в фазе, на другом в противофазе с током на входе.The input signal converters each have two outputs, and the voltage at one of the outputs is in phase, the other is in antiphase with the input current.

Напр жение с выходов преобразователей 1, 2, 3 поступает через коммутатор 5 на входы многополюсников 6, 7 и 8, обеспечивающих фильтрацию симметричных составл ющих и имеющих по три входа дл трех напр жений пропорциональных токам фаз А, В и С. Параметры этих многополюсников подбирают таким образом, чтобы передаточна функци по каждому отдельному входу соответствующих фаз удовлетвор л следующим соотношени м.The voltage from the outputs of converters 1, 2, 3 goes through switch 5 to the inputs of multipoles 6, 7 and 8, which provide filtering of symmetrical components and having three inputs for three voltages proportional to the currents of phases A, B and C. The parameters of these multipoles select so that the transfer function for each individual input of the corresponding phases satisfies the following relation m.

Дл многополюсника 6, обеспечивающегоFor a multipole 6, providing

Claims

filtering of the component of direct alternation. . V tij Kc (p) -T (For a multipole 7, providing filtering of the reverse phase alternation component; K, (p) 1; KB - ;; § :; Kc (Pl - ifl pfi,. For a multipole 8, providing filtering component of zero phase alternation. Cd (p) - 1 KV (P) - 1 Cd (p) - 1 At the output of the filter 4 of the symmetric pressure, a voltage can be obtained - (K, 6.4K232 –adK where K. , Kj and Kjj are coefficients that take into account the proportion of each symmetric component. Using switch 5, the symmetric components of a certain combination of multipoles are included in the filtering circuit to obtain on the output of the filter, proportional to a certain combination of symmetrical component currents. The voltage from the output 4 of the symmetric components is fed to the input of the rectifier 9, in which the rectification and smoothing of the input voltage is applied. The voltage is smoothed directly by one from the inputs of the threshold element, and through the delay element 1O to the second input. The transfer function of the delay element, taking into account the inverting property. K (p) is a constant coefficient; - constant latency time. The time constant determines the delay time of the output signal by the ratio & ny to the input signal / iy. Under normal conditions, the voltage at the inputs of the threshold element 1.4 of the comparator is equal in magnitude and opposite in sign, which leads to their mutual compensation, and therefore the threshold element is kept in the initial state by the input ( third input. During a short circuit in the power system, the voltage at the output of the rectifier changes dramatically. If the voltage at the first input of the threshold element 14 arrives without delay, it arrives at its second input with a delay due to the transient There is no delay, which leads to the appearance of a difference signal, and therefore a threshold element is triggered. Under the conditions of swing, which are characterized by a slower change in voltage at the output of the rectifier 9 than during short circuits, the voltage at the output of the delay element changes simultaneously with the signal at the output of the rectifier, or it is delayed by a small amount of voltage and the threshold element continues to be held in the initial state by the bias voltage. The introduction of a lag element significantly increases the sensitivity of the filter - current relay. Such a current relay filter can also be used as a device for blocking relay protection when oscillations in the power system are concerned. Claims of the invention Filter - current relay according to the author. St. No. 502439, characterized in that, with the aim of increasing its sensitivity and expanding its functionality, a delay element is additionally included between the rectifier output and the second input of the horn element.