SU1610518A1 - Device for determining polarity of taps of transformer converter windings - Google Patents

Abstract

The invention relates to the field of electrical engineering and can be used in relay protection for the correct inclusion of current sensors of differential, total and directional protection. The aim of the invention is to increase reliability, expand the field of use, reduce size. The device contains a test signal generating unit connected to the primary winding of the current sensor transformer, and an indication unit consisting of two comparators, And elements, and two RS-flip-flops with alarm LEDs. The precharged capacitor is discharged through the thyristor to the sensor winding. When the sensor is correctly phased, a pulse appears at its output, which triggers the first comparator 7 and the trigger 11. If the phasing is incorrect, another comparator 8 and the trigger 12 are activated. 2 Il.

Description

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The invention relates to electrical engineering and can be used in protection to properly incorporate current sensors into emergency differential, total and directional protection circuits.

The purpose of the invention is to increase reliability, expand the scope, reduce overall dimensions,

FIG. 1 shows a device for determining the polarity of the leads of transformer current sensors; in fig. . - timing diagrams explaining the operation of the device with,

A device for determining the polarity of the leads of a transformer current sensor 1 comprises a test signal generation unit 2 consisting of series-connected capacitors 3 and a thyristor 4 connected to the primary winding of the 1-current sensor, while the control electrode

thyristor 4 through the Start button 5 is connected to the positive voltage source + U, and the display unit 6 includes two comparators 7 and 8, two elements 9 and 10, two RS flip-flops 11 and 12, two LEDs 13 and 14, two resistors 15 and 16 and a reset button 17. The display unit is connected to the terminals of the secondary winding of the current sensor 1, while non-inverting

the input of the comparator 7 is connected to the inverting input of the comparator 8 and is connected to one of the terminals of the secondary winding of the sensor 1, and its second terminal and the free terminals of the comparators 7 and

8 are connected to the general power supply terminal, the inputs of the And elements are connected to the corresponding outputs of the Comparators 7 and 8, the S inputs of each RS flip-flop 11 and 12 are connected to the outputs of the corresponding elements And 9 and 10, and the R inputs of the RS flip-flops 11 and 12 connected via the Reset button with a power supply terminal 11 D1, the direct outputs of the flip-flops 11 and 12 are connected to each of the anodes of the LEDs 13 and 14, the cathodes of which are connected to the power supply through resistors and the inverse outputs of the flip-flops 11 and 12 9 and 10.

The device works as follows.

The capacitor is precharged to a certain voltage of a certain polarity (fig. F. Pos. 18) and discharged after pressing button 5

Start, producing a positive polarity pulse (Fig. 2, pos. 19). . When the current sensor is properly phased, a signal and g are generated at its output (Fig. 2, pos. 20). In this case, the comparator 7 is triggered, and the logical level 1 appears at the first input of the AND 9 element;

output is also logical 1, since trigger 12 is in the initial state, i.e. on the inverse output he has a high level. Thus, at the output of the AND 9 element, therefore, a high level appears at the S input of the trigger 11, the trigger fires and the LED 13 lights up with its direct output signaling the correct current sensor phasing.

The appearance of the negative part of the signal (in case of differentiation by the transreactor) (Fig. 2, pos. 20) does not affect the operation of the circuit, since element 10 is blocked by a signal from the inverse output of the trigger 11. To prepare the circuit for the next operating cycle, you must click 17 reset and re-charge the capacitor o If the current sensor 1 is incorrectly phased after pressing the 5 Start button, a pulse of 2 d is produced (Fig. 2, A03.21), the comparator 8 is triggered and switches the ignition trigger 12 through the element 10 to My output LED 17, signaling This is due to incorrect phasing of the current sensor. Simultaneously with the inverse output of the trigger 12 is blocked element And 9, prohibiting the passage of the second part of the pulse (figl, P03.21).

The advantages of this device are that it is made small-sized and convenient to operate, phases the current transformer and the transformer, increases the accuracy of determining the start of winding, the reliability of emergency protections.

Claims (1)

Invention Formula A device for determining the polarity of the winding leads of transformer converters, comprising a test signal generating unit made in the form of a series-connected voltage source and buttons whose outputs are intended. for connection to the primary terminals of the converter, and the display unit, the input of which is intended for connecting to the terminals of the secondary winding of a transformer converter, characterized in that, in order to increase reliability, expand the area of use and reduce dimensions, a capacitor and a thyristor are additionally inserted into the test signal generating unit, while the first output of the forming unit is test-. signal is connected to the negative pole of the voltage source and a capacitor, the second end of which is connected to the positive pole of the voltage source and the anode of the thyristor, the control electrode of which is connected via a button to the positive pole of the voltage source, and the cathode of the thyristor is connected to the second output of the forming unit test signal, the display unit is made on two comparators, two RS-flip-flops, two AND elements, and LEDs. Uc /eight (for /9 go resistors, the Reset button, the non-inverting input of the first comparator, which is the input of the display unit, is connected to the inverting input of the second comparator, the other inputs of the comparators are connected to the common output of their power source, which is connected to the output Q of the secondary winding of the transformer, the first the inputs of the AND elements are connected to the corresponding outputs of the comparators, each RS flip-flop is connected to the outputs of the AND elements, and the R-inputs of the RS flip-flops are connected to the common output via the Reset button source of power, to the straight output RS-flip-flops connected. LED nodes of the display LEDs, whose codes are connected through resistors (to the common output of the power source, and the inverse outputs of the RS flip-flops are connected to the second inputs of the AND elements,