RU2543072C2 - Method of control of spurious tripping and successful automatic reclosure of main circuit breaker in ring network line - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: when voltage and operating current disappears and no short circuit is available in the line of the main circuit breaker countdown is started for automatic reclosure delay time of the main circuit breaker (MCB). Voltage appearance and surge of the operating current is monitored and when its appears at ending of the delay time countdown the conclusion is made about spurious tripping and successful automatic reclosure of MCB. When using the suggested method data on spurious tripping and successful automatic reclosure of MCB may be obtained for the ring network line.

EFFECT: expansion of functionalities by receipt of data on the method of control of spurious tripping and successful automatic reclosure of MCB in the ring network line.

2 dwg

Description

The invention relates to the automation of electrical networks and is intended to control false shutdown and successful automatic restart (AR) of the head switch (GV) of the ring network line.

There is a method of monitoring the change in the state of the hot water in the ring network line, which consists in the fact that from the moment of the appearance of the inrush short circuit current (short circuit) at the beginning of the sectioned line of the ring network, the time equal to the response time of the hot water line protection is counted, and controls the moment the short circuit current is cut off . If the moment of the end of the countdown coincides with the moment of disconnection of the first short-circuit current inrush, then the fact of disconnection of the hot water is established. And then, from the moment of switching off the first inrush current, the short circuit starts counting the exposure time of the reclosure autogrower and the countdown of the total time equal to the exposure time of the reclosure autoclave and the response time of its protection with acceleration. At the same time, it controls the appearance of a second inrush current, and if at the end of the countdown of the reclosure time, there is no second inrush current with 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 reclosure loop of the GV line of the ring network is established. Or, at the end of the countdown of the reclosure time, the second short-circuit current appears, the value is more than the normal operating voltage, but less than the short-circuit current, then the fact of a successful reclosure of short-circuit recirculation appears, or if a second surge of the short-circuit current appears at the moment the countdown of the reclosure time of reclosure is established, then the fact of unsuccessful AR recirculation line loop network. And further, if after the appearance of the second short-circuit current surge, at the end of the countdown of the total time, the second short-circuit current surge does not turn off, then the fact of failure to turn off the hot water when it is turned on again is established [patent RU 2410817 C1, cl. H02J 13/00, 9/06, publ. 01/27/2011, bull. No. 3].

The disadvantage of this method is the impossibility of using it to control false shutdown and successful automatic re-enable of the hot water line of the ring network.

The objective of the invention is to expand the functionality of the method by obtaining information about false shutdown and successful automatic reclosure of the HV line of the ring network.

According to the proposed method, when voltage, operating current disappears and there is no inrush current short circuit in the main power supply line, the exposure time of the automatic reclosure HV is started, while the occurrence of voltage and inrush current is controlled and, if they appear at the end of the counted time, they conclude that shutdown and successful reclosure of hot water.

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.

The circuit (see figure 1) contains: power transformers 1 and 2; bus switches 3 and 4; section switch 5; head switches line 6 and 7; sectionalizing switches 8 and 9; switch 10 network point ABP; short circuit point 23; working current sensor (DRT) 11; short circuit current sensor (DTKZ) 12; voltage sensor (DN) 13. Elements: NOT 14, 15 and 16; And - 17; MEMORY 18; DELAY 19; SINGLE VIBRATOR 20; And 21; recording device (RU) 22.

The signal diagrams at the outputs of the elements shown in Fig. 1 with a short circuit at point 23 (see Fig. 1) has the form (see Fig. 2): 23 - at the output of element 11, 24 - at the output of element 12, 25 - at the output of element 13, 26 - at the output of element 14, 27 - at the output of element 15, 28 - at the output of element 16, 29 - at the output of element 17, 30 - at the output of element 18, 31 - at the output of element 19, 32 - at the output Element 20, 34 - in RU 22.

Figure 2, in addition to the diagrams of the output signals of the circuit elements, also shown: t ₁ - the time of the disappearance of voltage and operating current; t ₂ - the time instant of occurrence of voltage and operating current.

The method is carried out in the following way.

In normal network operation, switches 3, 4, 6, 7, 8, and 9 are on, and switches 5 and 10 are off. There is no short circuit current, therefore, there is no signal at the output of DTKZ 12 (Fig. 2, Diagram 24), and there is a signal at the output of DRT 11 (Fig. 2, Diagram 23), therefore there is no signal at the output of element NOT 14 (Fig. 2 , Diag. 26) and there is a signal at the output of DN 13 (Fig. 2, Diagram 25), therefore, there is no signal at the output of signal NOT 16 (Fig. 2 Diag. 28). The presence of only one signal on the element And 17 will not lead to its operation (figure 2, diagr.29), so the circuit is in control mode.

With a false shutdown of the GV 6, the voltage and operating current will disappear, therefore, the signal from the output of the DRT 11 will disappear (Fig. 2, Diagram 23, time t ₁ ), and the output of the element NOT 14 will receive a signal (Fig. 2, Diagram 26). This signal will go to the first input of element And 17. At the second input of this element, the signal will be saved (Fig. 2, Diagram 27), and the disappearance of voltage will ensure the disappearance of the signal from DN 13 (Fig. 2, Diagram 25) and the appearance of the signal at the output element NOT 16 (Fig.2. diag. 28), while the element And 17 will work (Fig.2, diag. 29). The signal of the element And 17 will go to the input of the element MEMORY 18, it will be remembered by it (Fig. 2, Diagram 30) and will go to the input of the element DELAY 19. From the output of this element, the signal will appear after the exposure time of the automatic recirculation device GV 6 (Fig. 2, Diagram 31 ) and will go to the input of the SINGLE-VIBRATOR element 20. It will make one oscillation (Fig. 2, Diagram 32), this signal will “discard” the memory from the element 18 (Fig. 2, Diagram 30), and it will go to the first input of the And element 21. At this point in time (t ₂ ), the GV 6 will turn on, and the voltage and operating current will appear in the line. This will ensure the appearance of the output signal on the elements of the DN 13 (Fig.2. Diag. 25, time t ₂ ). This signal will go to the third input of the And 21 element, while the absence of short-circuit current will ensure the presence of the output signal at the HE 15 element (Fig. 2, Diagram 27) and its presence at the second input of the And 21 element. It will work (Fig. 2, Diag. .33), its output signal will go to RU 22, and there will appear information that the switch 6 has turned off falsely and successfully automatically turned on again.

Thus, when using the proposed method, it is possible to obtain information about the false disconnection and successful automatic restart of the head circuit breaker of the ring network line.

Claims (1)

A method for monitoring false shutdown and successful automatic restart (AR) of the head circuit breaker (GW) of the ring network line, which consists in fixing the inrush currents and in measuring the time between them, characterized in that when the voltage, operating current and the absence of inrush current short circuit in the lines of the main power source begin counting the exposure time of the automatic reclosure HV, while controlling the appearance of voltage and the surge of the operating current and, if it appears at the end of the counting time, of nuisance tripping and reclosure successful GW.

Images