RU2318286C1 - Method for controlling failure to open short circuit followed by failure to disconnect automatic load-transfer center in ring circuit supplied with power from different buses of double-transformer substation - Google Patents

Abstract

FIELD: electric mains management engineering.

SUBSTANCE: proposed method includes measurement of first inrush short-circuit current in transformer buses of main power supply, storage of fact of its occurrence, counting of time longer than automatic reclosure time delay of circuit-breaker installed on backup line section adjacent to automatic load transfer center but shorter than automatic reclosure time of circuit breaker installed on section closer to substation buses compared with above-mentioned one, measurement of second inrush short-circuit current in transformer buses of main power supply; if this inrush current has been measured before measurement of mentioned time ceases, time equal to ON-time of load-transfer center delay is measured in ring circuit; by moment mentioned time measurement has ceased inrush short-circuit current is measured in transformer buses of stand-by power supply, fact of its occurrence is stored, and in the process failure to turn on automatic reclosure center in ring circuit is recognized and stored; at the same moment measurement of time longer than automatic-reclosure time delay of mentioned adjacent section but shorter than automatic reclosure delay time of circuit breaker on closer section is started; if second inrush short-circuit current occurs in transformer buses of stand-by power supply before measurement of this time is ceased, fact of failure to disconnect automatic load transfer center is stated.

EFFECT: enlarged functional capabilities.

1 cl, 2 dwg

Description

The invention relates to the automation of electrical networks and is intended to control unsuccessful short circuit (short circuit) and subsequent failure to turn off the automatic transfer switch (ATS) point in a ring network powered by different buses of a two-transformer substation.

A known method of controlling the failure of the automatic switch-on point for short circuit, which consists in fixing the inrush currents of the short circuit and in measuring the time between them, according to which at the end of the countdown, control the appearance of the second inrush current on the tires of the backup power source and when it is established, establish the fact unsuccessful inclusion of the circuit breaker item ABP for short circuit [RF Patent. No. 2214667, cl. Н02J 13/00, 9/04, publ. 10/20/2003, Bull. No. 29].

The disadvantage of this method is the impossibility of determining the subsequent failure of disconnecting the ATS point in a ring network powered by different buses of a two-transformer substation.

The objective of the invention is to expand the functionality of the method by obtaining information about an unsuccessful short circuit and subsequent failure to disconnect the ATS point in a ring network powered by different buses of a two-transformer substation.

According to the proposed method, which consists in fixing the inrush current on the tires of the transformer of the main power source and the tires of the transformer of the backup power source, record the first inrush short-circuit on the tires of the transformer of the main power source, remember the fact of its appearance, start the countdown of the time, the longer delay time of the automatic restart (AR) of the circuit breaker installed on the adjacent section of the redundant line, but the time delay of the automatic reclosure of the circuit breaker installed on the substation nearest to the busbars , in relation to the above, the section of the reserved line, fix the second inrush short circuit on the transformer tires of the main power supply, due to the automatic reclosure of one of the circuit breakers installed in the redundant line, if this throw is fixed before the end of the above countdown, then the countdown equal to the time delay for switching on the ABP point in the ring network at the end of the reference time indicated the appearance of an inrush short-circuit on the tires of the transformer of the backup power source, they remember the fact of its appearance and at the same time establish that the ABP point in the ring network failed to turn on, remember this, at the same time begin to count down the time, the longer the automatic reclosure time of the circuit breaker installed on the section adjacent to the ABP point a backup line, but with a shorter exposure time of the automatic reclosure of a circuit breaker installed in the substation line closest to the substation tires, in relation to the above section of the backup line, and if, until the countdown ends, ins transformer backup power source, a second short-circuit current surge due to the action reclosing switch mounted on an adjacent portion of paragraph ABP backup line, then install the denial item off the ATS in the ring network, fed by different tires two-transformer substation.

The essence of the invention is illustrated using the 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 26 (see figure 1).

The circuit (see figure 1) contains a power transformer of the main power source T1; power transformer backup power source T2; section switch of tires Q3; redundant line sectioning switch Q4; redundant line sectioning switch Q5; section switch Q6, equipped with a point ABP; redundant section switch Q7; redundant section switch Q8; short circuit current sensor DTKZ 9; pulse shaper FI 10; MEMORY element 11; element And 12; DELAY element 13; REPEATER element 14; element And 15; short circuit current sensor DTKZ 16; pulse shaper FI 17; MEMORY element 18; element And 19; DELAY 20 element; registration device RU 21; MEMORY element 22; element And 23; registration device RU 24; pulse shaper FI 25; short circuit point KZ 26; DELAY element 27.

The signal diagrams at the outputs of the elements shown in FIG. 1 during a short circuit at point 26 (see FIG. 1) have the form (see FIG. 2): 28 — at the output of the DTKZ element 9; 29 - at the output of the element FI 10; 30 - at the output of the element MEMORY 11; 31 - at the output of the element And 12; 32 - at the output of the element DELAY 13; 33 - at the output of the element REPEATER 14; 34 - at the output of the element And 15; 35 - at the output of the element DTKZ 16; 36 - at the output of the element FI 17; 37 - at the output of the element MEMORY 18; 38 - at the output of the element And 19; 39 - at the output of the element DELAY 20; 40 - the availability of information in the element RU 21; 41 - at the output of the element MEMORY 22; 42 - at the output of the element And 23; 43 - the availability of information in the element RU 24; 44 - at the output of the element FI 25; 45 - at the output of the element DELAY 27.

In normal operation, the sectionalizing switch Q6, equipped with an ATS point, is turned off. There is no signal at the output of the DTKZ 9 element, so the circuit does not start.

When short at point 26, at the output of the DTKZ element 9, a signal appears (see FIG. 2, diagram 28), which is fed to the input of the pulse shaper FI 10. FI 10 generates a signal for the decay of the signal from DTKZ 9 (see FIG. 2, diagram 29) , as well as to the input of the DELAY 27 element, which starts the countdown of a longer AR time of the Q5 circuit breaker, but a shorter AR time of the Q4 circuit breaker. At the end of the countdown, the signal from the element DELAY 27 resets the element MEMORY 11 (see figure 2, diagram 45). The signal from the element FI 10 is fed to the input of the element MEMORY 11, which remembers the specified signal (see figure 2, diagram 30). The signal from this element is fed to one of the inputs of the element And 12. At the second input of the element And 12, the signal appears if short circuit at point 26 is stable, that is, after the unsuccessful operation of the automatic reclosure of switch Q5 or switch Q4. The signal from the output And 12 (see figure 2, diagram 31) is fed to the input of the DELAY 13 element, which starts the countdown of the time equal to the time delay for turning on the ATS point of the Q6 switch. At the end of the countdown of this time, the output of the DELAY 13 element will display a signal (see Fig. 2, diagram 32), which will reset the MEMORY element 11, and will also be repeated by the REPEATER element 14 with a specified duration (see Fig. 2, diagram 33) and will go to one of the inputs of the element And 15. The inclusion of the item ABP will lead to the appearance of an inrush short-circuit in the backup line, and at the output of the DTKZ element 16, a signal will appear that will go to the second input of the And 15 element (see figure 2, diagram 35), at the input of the FI element 17 (generating a signal from the decay of the signal from DTKZ 16 (see Fig. .2, diagram 36)), to one of the inputs of the AND 19 element and to the input of the DELAY 20 element, which starts the countdown of a longer AR time of the Q7 switch, but a shorter AR time of the Q8 switch (see Fig. 2, diagram 39) The signal from the output of the element FI 17 stores the element MEMORY 18 (see FIG. 2, diagram 37) and supplies the element to one of the inputs and And 19. At the output And 15, a signal appears and enters the RU 21 recorder, where information about the failed ATS is displayed (see figure 2, diagram 40). The same signal is remembered by the element MEMORY 22 (see figure 2, diagram 41) and from its output is fed to one of the inputs of the element And 23.

If a failure occurs in the disconnection of the ABP point of the Q6 switch, then the current is short-circuited. will occur with a Q7 switch equipped with a reclosure. Thus, after a time equal to the AR time delay of the Q7 circuit breaker, a short-circuit current surge will again appear in the backup line, which will lead to the appearance of a signal at the output of the DTKZ element 16 (see Fig. 2, diagram 35). This signal will go to the inputs of the corresponding elements AND 15, AND 19, FI 17 and DELAY 20. The appearance of this signal at the input And 15 will not lead to the appearance of a signal at the output of this element, since at this time there is no signal at its second input. There will also not be a restart of the DELAY 20 element, since at this time the countdown of the above time continues. A signal will appear at the output of the And 19 element (see FIG. 2, diagram 38), since a signal will be present at both of its inputs. The signal from the output of the element And 19 will go to one of the inputs of the element And 23, at the second input of which there is a signal from the element MEMORY 22. At the output of the element And 23, a signal will appear and will go to the recorder RU 24, which will display information about the failure to turn off the ATS item switch Q6 (see figure 2, diagram 43). The signal from the element FI 25, formed by the decline of the signal of the element And 19, will reset the element MEMORY 22 (see figure 2, chart 44), and at the end of the countdown of the set time, the signal from the element DELAY 20 will reset the element MEMORY 18 (see figure 2 , diagram 39). The circuit will return to its original state.

If short at point 26 is unstable, then after the operation of the sectioning switch of the Q4 line, the signal at the output of the DTKZ element 9 does not appear, therefore, there is no signal at the output of the element And 12. The circuit will return to its original state.

If stable short circuit If it doesn’t happen at point 26, but on the section of the redundant line between the Q5 and Q4 switches, the ATS will be successful, since the Q5 switch will be turned off by dividing automatics and the ATS point will be switched on to short. therefore does not happen. There will be no signal at the DTKZ 16 output, the circuit will not work.

If there is an unsuccessful inclusion of the ABP point in the short circuit at point 26, but there will be no failure to turn it off, then in this case there will be no second inrush short-circuit in the backup line due to the reclosure of the Q7 circuit breaker. At the end of the set time, the signal from the DELAY 20 element will reset the MEMORY 18 element, the circuit will return to its original state. In the RU 21 registration device, information about the unsuccessful inclusion on the short circuit will be displayed paragraph ABP.

Thus, the proposed method allows to provide timely information about the unsuccessful inclusion on the short circuit and subsequent failure to disconnect the ABP point in the ring network, powered by different buses of the two-transformer substation. This will undoubtedly lead to an increase in the reliability of power supply to consumers through the adoption, on the basis of the information received, by the operational staff of the necessary decisions. The method has enhanced functionality by obtaining information about the specified situation in the event that the redundant and backup line circuit breakers are equipped with automatic reclosure devices.

Claims (1)

A method for controlling an unsuccessful short circuit (short-circuit) and subsequent failure to turn off the automatic transfer switch (ATS) point in a ring network powered by different buses of a two-transformer substation, which consists in fixing the inrush currents on the transformer buses of the main power source and the backup transformer buses a power source, characterized in that they fix the first inrush short-circuit current on the tires of the transformer of the main power source, remember the fact of its appearance, start the countdown of the time, the longer delay time of the automatic restart (AR) of the circuit breaker installed on the adjacent section of the redundant line, but the time delay of the automatic reclosure of the circuit breaker installed on the substation nearest to the busbars , in relation to the above, the section of the reserved line, fix the second inrush short circuit on the transformer tires of the main power supply, due to the automatic reclosure of one of the circuit breakers installed in the redundant line, if this throw is fixed before the end of the above countdown, then the countdown equal to the time delay for switching on the ABP point in the ring network at the end of the reference time indicated the appearance of an inrush short-circuit on the tires of the transformer of the backup power source, they remember the fact of its appearance and at the same time establish that the ABP point in the ring network failed to turn on, remember this, at the same time begin to count down the time, the longer the automatic reclosure time of the circuit breaker installed on the section adjacent to the ABP point a backup line, but with a shorter exposure time of the automatic reclosure of a circuit breaker installed in the substation bus closest to the substation tires, in relation to the above section of the backup line and, if until the end of the countdown, this time is ins transformer backup power source, a second short-circuit current surge due to the action reclosing switch mounted on an adjacent portion of paragraph ABP backup line, then install the denial item off the ATS in the ring network, fed by different tires two-transformer substation.

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