RU2542748C1 - Method named after l.d. surov to control prohibition of automatic reclosing of main circuit breaker in line during first cycle with subsequent successful reclosure during second cycle - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: since occurrence of fault current surge the countdown is started, which is equal to the delay time of the MCB protection actuation at that monitoring presence of fault current, and when fault current disappears upon completion of the above countdown then the conclusion is made on the MCB closure; upon disconnection of fault current the parameters are measured in the line by sounding pulses sent to all the line wires, the time of signals passing to all reflection points and distances are measure and the parameters are compared with parameters of the normal mode received in similar way in normal operating conditions, and when upon disconnection of fault current till completion of the countdown the parameters are different from the parameters in normal mode, the conclusion is made that short circuit is not self-repaired, the prohibition is set for automatic reclosure of the MCB and measurement of the parameters in the line and their comparison with the normal mode parameters is continued, and when at any moment before ending of the protection operation delay time with speedup plus the MCB switchover delay time for the second cycle the compared parameters are similar, the conclusion is made that short circuit is self-repaired, the prohibition signal is lifted and when at the moment of completion of the MCB switchover delay time for the second cycle surge of operating current appears in the line, then conclusion is made about successful reclosure of the MCB in the line during the second cycle of automatic reclosure.

EFFECT: expanded functionalities due to prohibition of automatic reclosure of the MCB in the line during the first cycle with subsequent successful reclosure during the second cycle.

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Description

The invention relates to the automation of electrical networks and is intended to prohibit automatic re-activation (AR) of the head circuit breaker (GW) of the line during the first cycle, followed by successful switching on during the second.

There is a method of controlling the tripping and successful automatic reclosure of a sectionalizing circuit breaker in a ring network line, which consists in the fact that from the moment of the appearance of the first inrush of short circuit current (short circuit) on the busbars of a transformer supplying a line, a countdown starts equal to the response time of the protection of the sectioning circuit breaker, while control the moment of disconnection of the first short-circuit current surge and, if the end time countdown coincides with the moment of disconnection of the first short-circuit current surge, establish the fact of switching off the sectional switch of Tell. And then, from the moment of switching off the first inrush current, the short circuit of the reclosure time starts, the appearance of the second inrush current is controlled and, if at the end of the countdown of the reclosure time, an inrush appears with a value greater than the normal operating current, but less than the short-circuit current, then establish the fact tripping and successful reclosure of a sectioning switch installed in the ring network line [patent RU No. 2337453, class H02J 13/00, publ. 10/27/2008, bull. No. 30].

The disadvantage of this method is the impossibility of using it to prohibit the reclosure of the hot water line during the first cycle, followed by successful switching on during the second.

The objective of the invention is to expand the functionality of the method by prohibiting the reclosure of the HV line during the first cycle, followed by successful switching on during the second.

According to the proposed method, from the moment of the appearance of a short-circuit current inrush, a countdown starts equal to the duration of the protection delay of the hot water supply, while the moment of disappearance of the short-circuit current is monitored, and if it disappears at the end of the exposure time of the protection of the hot water supply, it is concluded that the hot water is turned off, after the current SC determine the line parameters by sending probe pulses to all wires, measure the time of their passage to all reflection points and calculate the distances to these points, compare them with the parameters of the normal mode obtained in a similar way during normal operation of the line, and if the calculated parameters after the short-circuit current shutdown before the end of the reclosure time are different from the parameters of the normal mode, they conclude that the short circuit is not self-resetting, they prohibit reclosure and continue determine the parameters of the line after switching off the short-circuit current and compare them with the parameters of the normal mode and, if at some point in time before the end of the delay time of the operation of the protection with acceleration plus the exposure time of the second cycle of automatic reclosure, compare These parameters will become the same, make a conclusion about the self-elimination of faults, remove the inhibit signal, and if an inrush current occurs in the line at the end of the exposure time of the second reclosure cycle, they conclude that the reclosure line was successfully turned on during the second reclosure cycle.

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

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

- figure 2 is a diagram of the signals at the outputs of the elements shown in figure 1 with an unstable short circuit at point 26 (see figure 1).

The circuit (see Fig. 1) contains a short circuit current sensor (DTKZ) 1, a working current sensor (DRT) 2, elements: MEMORY 3, 5, 9, 11 and 15; NOT 4; DELAY 6, 12 and 16; SINGLE-VIBRATOR 7, 10, 13 and 17; And 8, 14, and 18; information processing unit (BOI) 19; sounding pulse generator (GZI) 20; probing pulse receiver (PZI) 21; recording device (RU) 22; power transformer 23; substation tire switch 24; head switch line 25; short circuit point 26.

The signal diagrams at the outputs of the elements shown in figure 1 with a short circuit at point 26 (see figure 1) have the form (see figure 2): 27 - at the output of element 1, 28 - at the output of element 2, 29 - at the output of element 3, 30 - at the output of element 4, 31 - at the output of element 5, 32 - at the output of element 6, 33 - at the input of element 7, 34 - at the input of element 8, 35 - at the input of element 9, 36 - at the output of element 10, 37 - at the output of element - 11, 38 - at the output of element 12, 39 - at the output of element 13, 40 - at the output of element 14, 41 - at the output of element 15, 42 - at the output of element 16, 43 - at the output of the element 17, 44 - at the output of the element 18, 45 - at the output of element 19, 46 - at the output of element 20, 47 - at the output of element 21, 48 - in RU 22. Figure 2 also shows: t ₁ - time of occurrence of short-circuit current, t ₂ - time of disappearance of short-circuit current, t ₃ - the time of the introduction of the ban on the reclosure of the GV 25, t ₄ - the end of the exposure time of the first cycle of the reclosure of the GV 25; t ₅ - the time of the end of the shutter speed of the protection with acceleration GV 25, t ₆ - the time of the self-elimination of the short circuit current, t ₇ - the time of the end of the shutdown time of the second cycle of automatic recirculation GV 25.

The method is as follows.

In normal line operation, switches 24 and 25 are on. At the same time, there is no signal at the output of DTKZ 1 (Fig. 2, Diagram 27), therefore, the circuit is in control mode.

When an unstable fault occurs at point 26, a signal appears at the output of the DTKZ 1 (Fig. 2, Diagram 27, time t ₁ ). This signal will go to the inputs of the MEMORY 3 and NOT 4. The signal received at the input of the MEMORY 3 element will be memorized by it (Fig. 2, Diagram 29) and will be fed to the input of the DELAY 6. The output of this element will appear after the response delay time protection ГВ 25 (Fig. 2, Diagram 32) and will go to the input of the SINGLE-VIBRATOR element 7. It will produce one oscillation (Fig. 2, Diagram 33), this signal will "clear" the memory from element 3 (Fig. 2, Diagram. 29) and will go to the first input of element And 8. At this point in time (t ₂ ), the hot water supply 25 will turn off, the short-circuit current will disappear (Fig. 2, Fig. 27, time t ₂ ) and again the output signal appears on the element NOT 4 (figure 2, diag.30). This signal will go to the second input of the And 8 element, it will work (Fig. 2, Diagram 34) and its output signal will go to the RU 22 and it will display information on the shutdown of the GV 25 (Fig. 2, Diagram 48). Also, this signal will go to the input of the MEMORY 9 element, it will be remembered by him, and from its output (Fig. 2, Diagram 35) it will go to the first input of the BOI 19. This element will send a signal to the GZI 20 (Fig. 2, Diagram 45), at the same time, sounding pulses will go from its output to all wires of the line (Fig. 2, Fig. 46). These pulses will reach the reflection points, will return back and go to the FDI 21, and from its output (Fig. 2, Diagram 47) will go to the second input of the BOI 19. This element will calculate the line parameters after switching off the GV 25 and compare them with the parameters of the normal modes that are obtained in a similar way in normal operation. And if the calculated parameters differ from the normal parameters, then at the second output of the BOI 19 a signal will appear (Fig. 2, Diagram 45), which will go to the input of the MEMORY 5 element, will be remembered by it (Fig. 2, Diagram 31), and will give a signal to prevent automatic reclosure of the first cycle of hot water 25. In this case, the calculation of the line parameters after switching off the hot water 25 and their comparison with normal parameters will be carried out until the fault is eliminated, and if it does not happen before the end of the exposure time of the second reclosure cycle, then the prohibition signal will not be removed, and the reclosure of the GV 25 will not happen. Also, this signal will go to RU 22, and there will appear information that a ban has been entered on the AR of the first cycle (Fig. 2, Diagram 48, time t ₃ ). The output signal of the element And 8 will also go to the input of the element MEMORY 11, it will be remembered by it (Fig. 2, Diagram 37) and will go to the input of the element DELAY 12. From the output of this element, the signal will appear after the exposure time of the first reclosure cycle (Fig. 2, Diag. .38) and will go to the input of the SINGLE-VIBRATOR element 13. It will produce one oscillation (Fig. 2, Diagram 39), its signal will "erase" the memory from Element 11 (Fig. 2, Diagram 37) and will go to the first input of the And element 14. And if the short circuit at this point in time has not eliminated itself, then the ban on the reclosure of the first cycle of GW 25 will remain, and at the output of the element NOT 4 will be with drove (2, diagr.30), and it will be present at the second input of AND element 14, so it works (2, diagr.40). Assume that the short circuit eliminated at time t ₆ . In this case, the calculated parameters of the line at time t ₆ will be equal to the normal parameters, and then at the third output of the BOI 19 a signal will appear (Fig. 2, Diagram 45), which will be input to the SINGLE-VIBRATOR element 10, it will produce one oscillation (Fig. 2, Fig. 36). This signal “erases” the memory from elements 5 and 9 (FIG. 2, FIG. 31 and 35), while the GZI 20 will stop sending probe pulses to the line (FIG. 2, FIG. 47), and the ban on AR reclosure will be lifted 25 (Fig. 2, Diagram 48). Also, the signal from the SINGLE-VIBRATOR 10 element will arrive at RU 22 and there will appear information that the short circuit has removed itself (Fig. 2, Diagram 48). The output signal of the element And 14 will go to the input of the element MEMORY 15, will be remembered by it (Fig. 2, Diagram 41) and will go to the input of the element DELAY 16. From the output of this element, the signal will appear at the end of the exposure time of the reclosure of the second cycle of GW 25 (t ₇ ) (Fig. 2, Diagram 42) and will be received at the input of the SINGLE-VIBRATOR element 17. It will produce one oscillation (Fig. 2, Diagram 43), this signal will “discard” the memory from element 15 (Fig. 2, Diagram 41) and it will go to the second input of the And element 18. At the same time, the automatic recirculation device ГВ 25 will occur, the output signal to the DRT 2 (Fig. 2, Diagram 28) will appear, which will go to the first electronic input element And 18. It will work, its output signal (Fig. 2, Diagram 44) will go to RU 22, and there will appear information on the successful activation of the GV 25 (Fig. 2, Diagram 48).

Thus, the proposed method allows to prohibit the automatic re-inclusion of the head line switch during the first cycle, followed by successful inclusion during the second.

Claims (1)

The method of prohibiting the automatic restart (AR) of the line circuit breaker (GW) during the first cycle and subsequent successful switching on during the second, which consists in fixing the inrush currents of short circuit (SC) and in measuring the time between them, characterized in that from the moment of occurrence Short-circuit current inrush begins a countdown equal to the duration of the short-circuit protection tripping time, while controlling the moment of short-circuit current disappearance and, if it disappears at the end of the short-time duration of the short-circuit protection tripping time, they conclude that When switching off the hot water, after switching off the short-circuit current, they determine the line parameters by sending probe pulses to all wires, measure the time of their passage to all reflection points and calculate the distances to these points, compare them with the parameters of the normal mode obtained in a similar way with the normal mode of operation of the line, and if the calculated parameters after disconnecting the short-circuit current before the end of the exposure time of the automatic recirculating gas generator will differ from the parameters of the normal mode, then they conclude that the short circuit is not self-resetting, a ban on the automatic recirculating gas generator and food They want to further determine the parameters of the line after switching off the short-circuit current and compare them with the parameters of the normal mode and, if at some point before the end of the holding time of the protection with acceleration plus the holding time of the second reclosure cycle, the compared parameters become the same, then they conclude Short circuit, remove the inhibit signal and, if at the end of the exposure time of the second reclosure of the hot water reclaim line, an inrush current appears in the line, then they conclude that the hot water line is turned on successfully during the second reclosure cycle.

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