SU904063A1

SU904063A1 - Input device for current protection system

Info

Publication number: SU904063A1
Application number: SU802945997A
Authority: SU
Inventors: Александр Александрович Рабочий
Original assignee: Новочеркасский ордена Трудового Красного Знамени политехнический институт им. Серго Орджоникидзе
Priority date: 1980-06-26
Filing date: 1980-06-26
Publication date: 1982-02-07

Description

(5) ВХОДНОЙ ОРГАН ДЛЯ ТОКОВОЙ ЗАЩИТЫ(5) INPUT BODY FOR CURRENT PROTECTION

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Изобретение относитс к электротехнике и предназначено дл использовани в устройствах токовой защиты.The invention relates to electrical engineering and is intended for use in current protection devices.

Известен входной орган дл токовой защиты, содержащий промежуточный элемент в виде двух трансреакторов, вторичные обмотки которых через выпр мительные диоды подключены к цепи, состо щей из параллельно соединенных ветвей, одна из которых образована балластным резистором, а втора последовательно соединенными шунтирующим диодом и конденсатором,причем нагрузочный резистор включен параллельно шунтирующему диоду СП Наличие дополнительного трансреактора усложн ет устройство и снижает его надежность.A current protection input element is known, containing an intermediate element in the form of two transreactors, the secondary windings of which are connected through a rectifying diode to a circuit consisting of parallel-connected branches, one of which is formed by a ballast resistor, and the second is connected in series by a shunt diode and a capacitor, A load resistor is connected in parallel with the AC shunt diode. The presence of an additional transreactor complicates the device and reduces its reliability.

Известно также устройство дл токовой защиты, содержащее трансформатор тока, к вторичной обмотке которого подключены диоды дл разделени полуволн тока, конденсаторыIt is also known a device for current protection, containing a current transformer, to the secondary winding of which diodes are connected to separate the half-current, capacitors

соединенные последовательно с разделительными диодами, и балластные резисторы, подключенные параллельно конденсаторам. Нагрузка в таком устройстве подключаетс к разноименным выводам разделительных диодов на сумму напр жений конденсаторов 21.connected in series with separation diodes, and ballast resistors connected in parallel with capacitors. The load in such a device is connected to the opposite terminals of the separation diodes for the sum of the voltages of the capacitors 21.

Недостатком указанного устройства вл етс низка надежность из-за возможности отказа при небольших The disadvantage of this device is low reliability due to the possibility of failure with small

10 погрешност х измерительного (основного ) трансформатора тока в переходном режиме короткого замыкани С 3.10 errors of measuring (main) current transformer in transient mode of short circuit С 3.

Цель изобретени - повышение на15 дежности устройства.The purpose of the invention is to increase the reliability of the device.

Поставленна цель достигаетс тем, что во входно,й орган дл токовой защиты, содержащий промежуточный трансформатор тока, вторична The goal is achieved by the fact that in the input body for current protection, containing an intermediate current transformer, a secondary

Claims

20 the winding of which is shunted by a resistor, and its first output is connected to the anode of the first separation diode, the cathode of which is connected to the 39 first face of the first capacitor and the first output of the first ballast resistor, and the cathode of the second separation diode, the anode of which is connected to the first facing of the second capacitor and the first output the second ballast resistor, the second conclusions of the ballast resistors are connected to the second output of the secondary winding of the intermediate current transformer, load resistor, additionally There are two diodes, and the second plates of the first and second capacitors, between which the load resistor is connected, are connected respectively to the first cathode and the second diode anode, and the first anode and second cathode are connected to the second output of the secondary winding of the intermediate current transformer . FIG. 1 shows a circuit diagram of the device; in fig. 2 is a diagram of his work. The device contains an intermediate current transformer 1, to the secondary winding of which are connected separating diodes 2 and 3 transient current passing through the ballast resistors TS and S capacitors 6 and 7, a shunt resistor 8, a load resistor 9 and additional diodes 10 and 11. The device operates as follows. The in current passing through the primary winding of the intermediate transformer 1 causes current to appear. Alternately in isolation diodes 2 and 3, the current flows in resistors k, 5 and 8, in a resistor 8 flows a sinusoidal current, and in resistors and 5 half-waves of the current, forming the corresponding drops voltage across these resistors. Under the action of these voltage drops through the capacitors 6 and 7 the load resistor and the corresponding diodes 10 and 11, a current flows causing the output voltage across the resistor 9-B. Each half-period current flows through the corresponding capacitor until the voltage on the capacitor reaches the voltage drop at the corresponding ballast resistor, after which the current in the load resistor 9 stops and the capacitors are discharged through the corresponding ballast resistor. The charge of the capacitor 7 occurs through the diode 10, the discharge is carried out through the diode 11. The charge and discharge of the capacitor 6 is carried out respectively through the diodes 11 and 10. In the device, the signal is differentiated (current half-wave) and the subsequent charge of the capacitor to Zero initial conditions. Due to the fact that the amplitude of the output signal Ugy is reached before the amplitude of the input current igj ((FIG. 2), higher operating errors of the measuring current transformers can be prevented, which ensures more reliable operation devices. Invention element for overcurrent protection, containing an intermediate current transformer, the secondary winding of which is bounded by a resistor and an anode of the first isolation diode connected to its first output and the cathode of the first capacitor of the first capacitor and the first output of the first ballast resistor and cathode the second separation diode, the anode of which is connected to the first plate of the second capacitor and the first output of the second ballast resistor, the second conclusions of the ballast resistors under Connected to the second output of the secondary winding of an intermediate current transformer, a load, characterized in that, in order to increase its reliability in operation, two diodes are additionally introduced into it, and the second on-off capacitors of the first and second capacitors, between which the load resistor is connected, are connected respectively, the cathode of the first and the anode of the second diode, and the anode of the first and the cathode of the second diode are connected to the second output of the secondary winding of the intermediate current transformer. Sources of information taken into account in the examination of the 1st USSR Author's Certificate No. 630668, cl. H 02 H 3/08, 1977,

2. To produce universities, ser. Electromechanics, 1970, № 3, p. S (prototype).

3. To produce universities, ser. Electrical Mechanics, 1971, No., p. 373.

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