RU2543073C2 - Method named after l d surov to control successful automatic reclosure of main circuit breaker in line without intermediate fault close-ins - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention is intended for successful automatic reclosure of the main circuit breaker (MCB) in the line without intermediate fault close-ins. Technical result lies in expansion of functionality by receipt of data on successful automatic reclosure of the MCB in the line without intermediate fault close-ins. According to the suggested method since occurrence of fault current surge the first countdown is started, which is equal to the delay time of the MCB protection actuation at that monitoring presence of fault current, when fault current disappears upon completion of the first countdown then the conclusion is made on the MCB closure; since the first countdown is over the second countdown is started, which is equal to the total delay time for all cycles of the MCB automatic reclosure, and sounding pulses are sent to all the line wires with a certain periodicity and the line parameters are defined upon disconnection of the fault current by identification of all reflection points and calculation of distances up to these points and by their comparison with parameters of the normal mode received in similar way in absence of the fault current; when the parameters do not coincide the signal is sent to the MCB automatic reclosure and the signal will be valid till the compared parameters are matched, and if it takes place before completion of the second countdown then delivery of sounding pulses is stopped, the prohibition is lifted and the signal is start foe automatic reclosure of the MCB.

EFFECT: when using the above method the data may be received on successful automatic reclosure of the main circuit breaker in the line without intermediate fault close-ins.

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Description

The invention relates to the automation of electrical networks and is intended to control the successful automatic restart (AR) of the head circuit breaker (GW) of the line without intermediate connections for short circuits.

There is a method of monitoring changes in the state of the hot water in the ring network line, which consists in the fact that since the appearance of an inrush short-circuit current (short circuit) at the beginning of the partitioned line of the ring network, the time equal to the response time of the hot water line protection is counted. At the same time, the time of the inrush of the short circuit is controlled, and if the time at the end of the countdown coincides with the moment of disconnection of the first inrush, then the fact of disconnecting the hot water is established. Then, from the moment of switching off the first inrush short-circuit current, they start the countdown of the reclosure time and the total time equal to the reclosure time of the reclosure and the response time of its protection with acceleration. In this case, the appearance of the second inrush is controlled, and if at the end of the countdown of the reclosure time there is no second inrush of a value greater than the normal operating current, but less than the short-circuit current or equal to the short-circuit current, then the fact of the reclosure of the high-voltage reclosure line circuit, or at the end of the countdown, is established of the AR time, a second current surge appears with a value greater than the normal operating one, but less than the short-circuit current, then the fact of successful AR reclosure of the GW line of the ring network is established. And if there is a second short-circuit current surge at the end of the countdown of the AR recirculation time, then the fact of unsuccessful recirculation of the recirculation line of the ring network is established. And further, if after the appearance of the second inrush current short circuit at the end of the countdown of the total time, the second inrush current does not turn off, then the fact of failure to turn off the hot water when it is turned off again is established [patent RU No. 2410817, cl. H02J 13/00, 9/06, publ. 10/27/2011, bull. Number 3].

The disadvantage of this method is the impossibility of using it to control the successful automatic restart of the line circuit breaker without intermediate short circuit breakers.

The objective of the invention is to expand the functionality by obtaining information about the successful automatic re-inclusion of the head switch of the line without intermediate connections for short circuits.

According to the proposed method, from the moment of the appearance of a short-circuit current inrush, the first countdown starts, equal to the exposure time of the GW protection, and the disappearance of the short-circuit current is controlled, and if it disappears at the end of the first countdown, then it is concluded that the GV is turned off, from the moment the first countdown ends time, a second countdown starts, equal to the total exposure time of all AR recycle cycles, and probe pulses are sent to all wires of the line with a certain frequency, and the line parameters are determined after switching off the short circuit current by determining all reflection points and calculating the distances to these points, and compare them with the parameters of the normal mode, obtained in a similar way if there is no short circuit in the line, and if they do not coincide, they signal to block the automatic reclosure of HV, which will remain until the moment when the compared parameters become the same, and if this happens before the end of the second countdown, then stop sending the probe pulses, remove the ban and send the signal to the automatic reclosure.

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 signal diagram at the outputs of the elements shown in figure 1 with an unstable short circuit at point 4 (see figure 1).

The circuit (see figure 1) contains: power transformer 1; input switch 2; head switch 3; short circuit point 4; lines 5,6,7,8,9 and 10; short circuit current sensor (DTKZ) 11. Elements: MEMORY 12 and 17; NOT 13; DELAY 14 and 18; SINGLE VIBRATOR 15 and 19; And 16 and 20; information processing unit (BOI) 21; sounding pulse generator (GZI) 22; probe sounding pulses (PZI) 23; recording device (RU) 24.

The signal diagrams at the outputs of the elements shown in figure 1 with an unstable fault at point 4 (see figure 1) have the form (see figure 2): 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 - the output of element 20, 35 - at the output of element 21, 36 - at the output of element 22, 37 - at the output of element 23, 38 - in RU 24.

In Fig.2, in addition to the diagrams of the output signals of the circuit elements, t ₁ is the time instant of occurrence of an unstable fault at point 4, t ₂ is the time instant of disconnection of the fault current by the head switch 3, t ₃ is the time instant of occurrence of the inhibit signal for automatic reclosure GW 3, t ₄ is the time point of self-elimination of the fault, t ₅ is the moment of the end of the second countdown and successful reclosure GW 3.

The method is as follows.

In normal operation of the electrical network, switches 2 and 3 are on. There is no signal at the output of DTKZ 11 (Fig. 2, time t ₀ ), therefore, the circuit is in control mode.

When an unstable fault at point 4 at the output of the DTKZ 11, a signal will appear (Fig. 2, Diagram 25, time t ₁ ), which will be fed to the input of the element NOT 13, while the output signal that existed before will disappear (Fig. 2, Diagram .27), it will also go to the input of the element MEMORY 12, it will be remembered by it (Fig. 2, Diagram 26) and will go to the input of the element DELAY 14. At the output of this element, the signal will appear after the exposure time of the protection of the GV 3 (Fig. 2, diag. 28) and will go to the input of the SINGLE-VIBRATOR element 15. This element will produce one oscillation (Fig. 2, diag. 29) and its signal “reset um "memory element 12 (Figure 2 diagr.26) and go to a first input of AND gate 16. At this point in time (t ₂₎ short-circuit current is disconnected from the signal HS 3. DTKZ 11 disappear (Figure 2 Diagram .25, time t ₂ ) and a signal will appear from the element NOT 13 (Fig. 2, Diagram 27) which will go to the second input of And 16. And 16 will work, and its signal will appear at its output (Fig. 2, Diag. .thirty). This signal will go to RU 23, and there will appear information on the shutdown of the hot water 3 (Fig. 2, Diagram 38). Also, this signal will go to the input of the MEMORY element 17 and to the first input of the BOI 21. This element will send a signal (Fig. 2, Diagram 35) to the GZI 21, while probing pulses will go from its output to all wires of the line (Fig. 2, Fig. 36). They, reaching the reflection points and returning, will go to the FDI 23, and from its output (Fig. 2, Diagram 37) to the FIGHT 21. The FIGHTER 21 will determine the line parameters by determining all the reflection points and calculating the distances to these points and compare them with the parameters of the normal mode, obtained in a similar way with the normal mode of operation of the line (lack of short circuit in the line), and if they differ, then from the second output of the BOI 21 a signal will go (Fig. 2, Diagram 35) to prohibit the automatic reclosure of GW 3. The signal received at the input of the element MEMORY 17 will be remembered by him (Fig. 2, Diagram 31) and will be received at the input d delay element 18. The output signal of this element appears through the total time of reclosure Extracts 3 HS (2, diagr.32) cycles. And if until the time t ₅ at time t _{4 the} compared parameters become the same, then the ban is removed from the automatic recirculation gun ГВ 3, and from the BOI 21 the signal will arrive at the second input of the And 20 element (Fig. 2, Fig. 35). After the total shutter speed of all the reclosure cycles, the HV 3 signal from the DELAY 18 element (FIG. 2, Diagram 32) arrives at the input of the SINGLE VIBRATOR 19. It will produce one oscillation (FIG. 2, Diagram 33), will “reset” with its signal the memory from element 17 (FIG. 2, FIG. 31) and will go to the first input of AND element 20. At the same time, a signal from element NOT 13 will exist at its third input (FIG. 2, FIG. 27), so it will work (FIG. .2, diag. 34), its signal will go to RU 24, and to ГВ 3, it will turn on, and to RU 24 information will appear on the successful reclosure of ГВ 3 (Fig. 2, Diagram 38).

Thus, when using the proposed method, it is possible to obtain information about the successful automatic re-inclusion of the line head switch without intermediate switching on short circuits.

Claims (1)

The method of monitoring the successful automatic restart (AR) of the head circuit breaker (GW) of the line without intermediate switching to short circuits (short circuit), which consists in fixing the inrush current short circuit and in measuring the time between them, different the fact that from the moment of the appearance of the short-circuit current inrush, the first time count starts, equal to the duration of the operation delay of the hot water protection, while the disappearance of the short-circuit current is controlled, and if it disappears at the end of the first time count, then it is concluded that the hot-wire is turned off, from the moment the first the time starts the second time, equal to the total time of the shutter speeds of all the reclosure cycles, and probes are sent to all the wires of the line with a certain frequency, and the line parameters are determined after switching off the short-circuit current by defining dividing all the reflection points and calculating the distances to these points, and compare them with the parameters of the normal mode obtained in a similar way if there is no short circuit in the line, and if they do not match, they signal the prohibition of automatic reclosure of HV, which will remain until the parameters will become the same, and if this happens before the end of the second countdown, then stop sending the probe pulses, remove the ban and send the signal to the automatic reclosure.

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