RU2501145C1 - Method for control of spurious tripping of main and sectionalising circuit breakers with subsequent switching on of network breaker for automatic transfer switch (ats) in ring network line - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: according to the method since the moment of loss of voltage, operating current and non-availability of short-circuiting current in the line of main power supply source hold-up time-keeping is started for switching on of ATS network breaker; at that when this time is over in the line of main power supply source increase of operating current is tested and when at the moment of time-keeping ending operating current is increased to value equal to value of lost operating current in the line of main power supply source then summary is made about spurious tripping of the main and sectionalising circuit breakers and switching on of ATS network breaker.

EFFECT: broader functional capabilities.

2 dwg

Description

The invention relates to the automation of electrical networks and is intended to control the false shutdown of the head and sectioning switches with the subsequent inclusion of the circuit breaker of the automatic transfer reserve (ATS) network point in the ring network line.

There is a method of monitoring the false shutdown of the sectionalizing circuit breaker in a ring network line powered by different buses of a two-transformer substation, which consists in the fact that at the moment of detecting a 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 short-circuit inrush current (short-circuit) start the countdown equal to the standby time of the inclusion of the reserve, and at the end of the countdown of this time control the appearance rush current at the beginning of a backup power source line, and if there is a throw determined primary source is off load current supply line value, the fact is set false tripping sectionalizing switch in the ring network line [RF patent №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 the false shutdown of the head and sectioning switches with the subsequent inclusion of the circuit breaker of the network point for automatically turning on the reserve in the ring network line.

The objective of the invention is to expand the functionality of the method by obtaining information about the false shutdown of the head and sectionalizing switches, followed by turning on the switch of the network point of automatic inclusion of a reserve in the ring network line.

According to the proposed method, from the moment of the disappearance of voltage, operating current and the absence of short-circuit current in the main power supply line, the start-up time of the on-off switch of the ABP network item switch starts, and at the end of this time, the increase in the operating current is controlled in the backup power supply line and, if at the end of the countdown, the working current increased by a value equal to the value of the disappeared working current in the line of the main power source, then they conclude that the main and positioning switches and turning on the circuit breaker of the ABP network item.

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 (see figure 1).

The circuit (see Fig. 1) contains: a power transformer 1, an input switch 2 of the main power supply bus, a head switch 3 of the main power supply line, a sectional switch 4 of the main power supply line, an ABP network switch 5, a sectionalizer of the backup power supply line 6 power supply, head switch 7 lines of the backup power supply, section switch of buses of the substation 8, input switch 9 of the tires of the backup power supply, power transformer 10, current transformer (CT) 11, the sensor a short circuit (DTKZ) 12, element NOT 13, operating current sensor (DRT) 14, element NOT 15, voltage sensor (DN) 16, element NOT 17, element I 18, element MEMORY 19, element DELAY 20, element SINGLE-DISPLAY 21 , element And 22, current transformer (TT) 23, the sensor of the working current (DRT) 24, the recording device 25.

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): 26 - at the output of element 11; 27 - at the output of element 12; 28 - at the output of element 13; 29 - at the output of element 14; 30 - at the output of element 15; 31 - at the output of element 16; 32 - at the output of element 17; 33 - at the output of element 18; 34 - at the output of element 19; 35 - at the output of element 20; 36 - at the output of element 21, 37 - at the output of element 22; 38 - at the output of element 23; 39 - at the output of element 24; 40 - in RU 25.

In addition to the diagrams of the output signals, FIG. 2 also shows: t ₁ is the time instant of the disappearance of voltage and operating current in the line of the main power source, t ₂ is the time moment of the end of the shutter speed of the circuit breaker of the ABP network item.

The method is as follows.

In normal network operation, switches 2, 3, 4, 6, 7, and 9 are turned off, and switches 5 and 8 are turned off. Moreover, the presence of only one input signal on the element And 18 from the element NOT 13 (figure 2, Fig. 28) does not lead to its operation, so the circuit is in control mode.

In the case of tripping of the main switch 3 in the absence of short-circuit current in the main power supply line (false shutdown due to any malfunction), the signal disappears from the output of TT 11 (Fig. 2, Diagram 26, time t ₁ ) while it was not , the signal will not appear at the output of DTKZ 12 (Fig. 2, Diagram 27) and the output signal from the element HE 13, which will be present at the third input of the And 18 element (Fig. 2, Diagram 28), will be saved. Turning off the switch 3 will lead to the disappearance of the output signal from the DRT 14 (figure 2, Fig. 29) and the appearance of the output signal from the element NOT 15 (figure 2, diag. 30), which will go to the second input of the element And 18. When when the switch 3 is turned off from the output of DN 16, the signal will disappear (Fig. 2, Diagram 31), but a signal will appear from the element NOT 17 (Fig. 2, Diagram 32), which will go to the second input of the And element 18. The presence of all input signals to element And 18 will lead to its operation and the appearance of its output signal (figure 2, Fig. 33). This signal will go to the input of the MEMORY 19 element, it will be remembered by it (Fig. 2, Diag. 34) and will go to the input of the DELAY element 20. From the output of this element, the signal will appear after the shutter speed of the minimum voltage protection of circuit breaker 4 and the holding time of the circuit breaker 5 point ABP and will go to the input of the SINGLE-VIBRATOR element 21. This element will make one oscillation (Fig. 2, Diagram 36) and with its signal “discard” the memory from Element 19 (Fig. 2, Diagram 34) and go to the first input of the And element 22. The disappearance of voltage at the network point ABP with side of the main power supply of the power transformer 1 will lead to the inclusion of the switch 5. In this case, the working current at the output of the CT 23 will increase (Fig. 2, Fig. 38), due to the consumer connecting the main power supply line, and the output signal will appear at the output of the DRT 24 (Fig. .2, diag. 39), which, having entered the second input of the And 22 element, will ensure its operation (Fig. 2, diag. 37). The signal of this element will go to RU 25, and there will appear information about the false shutdown of the head 3 and sectioning 4 switches and turning on the switch 5 of the ABP network point.

Restoring the normal power supply circuit by turning on the switches 4 and 3 and turning off the switch 5 will bring the circuit to the initial state of control.

Thus, the proposed method allows to obtain information about the false shutdown of the head and sectioning switches with the subsequent inclusion of the switch of the network point of automatic inclusion of a reserve in the ring network line.

Claims (1)

A method for controlling the false shutdown of the head and sectioning switches with the subsequent turning on of the circuit breaker of the automatic transfer switch (ATS) network point in the ring network line, which consists in fixing the surges of short circuit currents (SC) and in measuring the time between them, characterized in that from the moment the voltage disappears , operating current and lack of short-circuit current in the main power supply line begin to count down the delay time for turning on the circuit breaker of the ABP network item, while at the end of this time in l The lines of the backup power source control the increase in the operating current and, if at the time the countdown ends, the operating current increases by a value equal to the value of the disappeared operating current in the line of the main power source, they conclude that the head and section switches are turned off and the circuit breaker of the ATS network point is turned on.

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