RU2502178C1 - Control method of faulty or emergency trip and failure of automatic reclosing of main switch of line that feeds transformer substation, and determination of short circuit type - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: from the moment of disappearance of voltage from transformer buses and at absence of SC current, time counting is started through it, which is equal to delay time of AR of MS, and sounding pulses are sent to all the line wires, time is measured, during which they reach reflection points, distances to those points are calculated, compared to each other and to the distance to MS installation place. If all the calculated distances are equal to each other and larger than distance to MS, conclusion is made on faulty MS trip, and if they are equal to each other and less than distance to MS or two calculated distances are equal to each other and less than the third one that is equal to distance to MS, a conclusion is made on emergency trip of MS; at the end moment of counted time there controlled is occurrence of voltage on substation buses, and if it did not appear, then sounding pulses are sent again to all the line wires, the time is measured, during which they will reach reflection points, distances to those points are calculated, compared to each other and to distance to MS, and if all the calculated distances are equal to each other and less than distance to MS, a conclusion is made on failure of AR of MS at stable three-phase SC, and if two of the calculated distances are equal to each other, but are less than the third one that is equal to distance to MS, a conclusion is made on failure of AR of MS at stable two-phase SC.

EFFECT: enlarging functional capabilities.

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Description

The invention relates to automation of electrical networks and is intended to control false or emergency shutdown and failure of automatic restart (AR) of the head switch (GV) of the line supplying the transformer substation, with the determination of the type of short circuit.

In the known method of monitoring the false shutdown of the sectionalizing circuit breaker in the ring network line, which consists in the fact that at the moment of detecting the drop in the operating current at the beginning of the main power supply line to a value determined by the load of the line connected after the sectioning circuit breaker and the absence of inrush current short circuit (short circuit) ) start the countdown of the time equal to the holding time of the switch of the automatic reserve switch point. At the end of the countdown of this time, the appearance of a current surge at the beginning of the backup power supply line is monitored and if a current surge occurs with a value determined by the disconnected load of the main power supply line, then the fact of a false disconnection of the sectioning switch in the ring network line is established [RF patent No. 2378754, cl. H02J 13/00, publ. 10/10/2010, bull. No. 1].

The disadvantage of this method is the impossibility of using it to control false or emergency shutdown and failure to automatically re-enable the head switch of the line supplying the transformer substation, with the determination of the type of short circuit.

The objective of the invention is to expand the functionality of the method by obtaining information about a false or emergency shutdown and refusal to automatically turn on the head switch of the line supplying the transformer substation, with the definition of the type of short circuit.

According to the proposed method, from the moment the voltage on the transformer tires disappears and there is no short-circuit current through it, a countdown equal to the exposure time of the automatic recirculation arrester is started, and probing pulses are sent to all the wires of the line, the time it takes for them to reach the reflection points is measured, the distances to these points, compare them with each other and with the distance to the location of the hot water and, if all the calculated distances are equal to each other and greater than the distance to the hot water, then make a conclusion about the false shutdown of the hot water, and if all the calculated distances I are equal to each other and less than the distance to the hot water supply, or two calculated distances are equal to each other and less than the third, which is equal to the distance to the hot water supply, then make a conclusion about the emergency shutdown of the hot water supply, at the end of the measured time, control the appearance of voltage on the substation buses and, if it does not appear, then probing pulses are sent to all wires of the line again, they measure the time for which they reach the reflection points, calculate the distances to these points, compare them with each other and with the distance to the hot water, and if all the calculated distances If the values are equal to each other and less than the distance to the hot water, then they conclude that the automatic reclosure of the hot water with a stable three-phase short circuit is denied, and if the two calculated distances are equal to each other, but less than the third, which is equal to the distance to the hot water, they conclude that the automatic reclosure of the hot water with a stable two-phase short circuit.

The essence of the invention is illustrated by drawings, where:

figure 1 presents a structural diagram containing elements for implementing the method;

figure 2 - diagrams of the signals at the outputs of the elements shown in figure 1, with a short circuit at point 2 (see figure 1).

The circuit (see Fig. 1) contains a head switch 1 of the line supplying the transformer substation, a short circuit point 2, a power transformer 3, an input bus switch 4, lines 5, 6, 7 extending from the substation tires, a short circuit current sensor (DTKZ) 8, element NOT 9, voltage sensor (DN) 10, element NOT 11, element MEMORY 12, element DELAY 13, element SINGLE-VIBRATOR 14, element AND 15, element MEMORY 16, element SINGLE-VIBRATOR 17, probe pulse generator (GZI) 18, receiver probing pulses (PZI) 19, the information processing unit (BOI) 20, the recording device (RU) 21.

The signal diagrams at the outputs of the elements shown in figure 1, when short circuit at point 2 have the form (see figure 2): 22 - at the output of element 8; 23 - at the output of element 9; 24 - at the output of element 10; 25 - at the output of element 11; 26 - at the output of element 12; 27 - at the output of element 13; 28 - at the output of element 14; 29 - at the output of element 15; 30 - at the output of element 16; 31 - at the output of element 17; 32 - at the output of element 18; 33 - at the output of element 19; 34 - at the output of element 20; 35 - at the output of element 21.

In addition to the diagrams of the output signals, FIG. 2 also shows: t ₁ is the time instant of the disappearance of voltage on the transformer tires; t ₂ - the time of the end of exposure to the reciever of hot water.

The method is as follows.

In the normal mode of operation of the substation, there is a signal at the output of DN 10 (Fig. 2, Diagram 24), therefore, there is no signal at the output of the element NOT 11 (Fig. 2, Diagram 25). There is no signal at the output of DTKZ 8 (Fig. 2, Diagram 22), but at the output of the element NOT 9 there is a signal (Fig. 2, Diagram 23), and it will be present at the second input of the And 15 element, and at its first input there will be no signal, so the circuit is in control mode.

If the voltage on the transformer tires disappears due to disconnection of the hot water supply 1, the signal disappears at the output of DN 10 (Fig. 2, Diagram 24, time t ₁ ), while a signal appears at the output of the HE 11 element (Fig. 2, Diagram 25 ) This signal will go to the input of the element MEMORY 16, it will be remembered by it (Fig. 2, diag. 30) and will go to the input of the element SINGLE-SELECTOR 17. It will make one oscillation (Fig. 2, diag. 31), with its signal it will "clear" the memory from the element 16 (FIG. 2, FIG. 30) and will arrive at the first input of the BOI 20. This element will send a signal (FIG. 2, FIG. 34) to the GZI 18, while probing pulses will go from its output to the line wires (FIG. 2 Diag. 32). Having reached the reflection points, they will return back and go to the FDI 19, and from its output (Fig. 2, Diagram 33) will go to the BOI 20. This element will determine the time for which the probe pulses reached the reflection points, calculate the distance to of these points and compares these distances with each other and with the distance to GV 1. And if all the calculated distances are equal to each other and greater than the distance to GV 1, then a signal will appear at the output of BOI 20 (Fig. 2, Diagram 34) , which will go to RU 21, where information about the false shutdown of the hot water 1 will appear (Fig. 2, Fig. 35). And if two calculated distances are equal to each other and less than the third, which is equal to the distance to GV 1, or all the calculated distances are equal to each other and less than the distance to GV 1, then from the output of BOI 20 to RU 21 a signal will go that will provide the appearance in it of information on the emergency shutdown of the hot water 1 (figure 2, diag. 35). The signal received at time t ₁ from the output of the element NOT 11 (Fig. 2, Diagram 25) to the element MEMORY 12 will be remembered by him (Fig. 2, Diagram 26) and will be received at the input of the element DELAY 13. From the output of this element the signal appears after the exposure time of the automatic recirculation gun ГВ 1 (Fig. 2, diag. 27) and arrives at the input of the SINGLE-VIBRATOR 14. It will produce one oscillation (Fig. 2, diag. 28), this signal will “clear” the memory from element 12 (Fig. .2, diag. 26) and will go to the first input of AND element 15. At this point in time, GW 1 should turn on, but this will not happen for any reason of a malfunction, therefore the ignal from the element NOT 9 (Fig. 2, diag. 23) will not disappear and will be present at the second input of the And 15 element, so it will work and its output signal (Fig. 2, diag. 29) will go to the second input of the BOI 20. At the same time, a signal will go from this element (Fig. 2, Diagram 34, time t ₂ ) in the GZI 18, which will again send probing pulses to the line wires (Fig. 2, Diagram 32). The pulses, reaching the reflection points and returning, will go to the FDI 19, and from its output (Fig. 2, Diagram 33) to the input of the BOI 20. This element will determine the time it takes for the probe pulses to travel the distance to the reflection points, calculate the distance to the reflection points and compares the calculated distances between themselves and with the distance to GW 1. And if all the calculated distances are equal to each other and less than the distance to GW 1, then the signal will be sent from the output of BOI 20 (Fig. 2, Diagram 34), which, having received in RU 21, will provide the appearance in it of information on the refusal of the reclosure of recirculation tank 1 with steady three-phase short circuit (Fig.2, diag. 35). And if the two calculated distances are equal to each other and less than the third distance, which is equal to the distance to GW 1, then from the output of BOI 20 to RU 21 a signal will go (Fig. 2, Fig. 34), which will provide information about the automatic reclosure failure GV 1 at a stable two-phase short circuit.

Thus, the proposed method allows to obtain information about a false or emergency shutdown and refusal to automatically turn on the head switch of the line supplying the transformer substation, determining the type of short circuit.

Claims (1)

The method of monitoring false or emergency shutdown and failure of automatic restart (AR) of the head switch (GV) of the line supplying the transformer substation, with the determination of the type of short circuit (short circuit), which consists in fixing the surges of short-circuit currents and in measuring the time between them, characterized in that from the moment of disappearance of voltage on the transformer tires and the absence of short-circuit current through it, a countdown is started equal to the exposure time of the automatic recirculation arrester, and probing pulses are sent to all wires of the line, the time for which f they reach the reflection points, calculate the distances to these points, compare them with each other and with the distance to the location of the hot water and, if all the calculated distances are equal to each other and greater than the distance to the hot water, they conclude that the hot water is turned off, and if all the calculated distances are equal to each other and less than the distance to the hot water, or two calculated distances are equal to each other and less than the third, which is equal to the distance to the hot water, then make a conclusion about the emergency shutdown of the hot water, at the end of the measured time control the appearance voltage on the substation tires and, if it does not appear, then probing pulses are sent to all wires of the line again, they measure the time for which they reach the reflection points, calculate the distances to these points, compare them with each other and with the distance to the hot water and all the calculated distances are equal to each other and less than the distance to the hot water, then make a conclusion about the automatic reclosure of the hot water with a stable three-phase short circuit, and if the two calculated distances are equal to each other, but less than the third, which is equal to the distance to the hot water, then make a conclusion about the failure AR reclaim at mouth ychivom two-phase short-circuit.

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