RU2461945C1 - Method for control of prohibition failure of reserve automatic switching in ring network line - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: at the moment of time counting finish there controlled is the appearance of second inrush of operating current exceeding normal or short circuit current on transformer buses of reserve source, if they are absent, then the fact of switching failure of ring network reserve automatic switching (RAS) is determined. According to the invention since the moment of the first short circuit current inrush appearance on transformer buses of main source there started is time counting equal to time delay of protection operation of sectionalising circuit breaker of line feeding from transformer of main source and there controlled is the switch-off moment of the first short circuit current inrush and if the short circuit current is switched off at the moment of counted time is over, there made is a conclusion that sectionalising circuit breaker is switched off, since the moment of the first short circuit current inrush switching off there started is the time counting equal to time delay of switching on of RAS network point switch plus time delay of protection operation with this switch acceleration and, if the second short circuit current inrush appears on transformer buses of reserve source at the moment when time delay of switching on of RAS network point switch is over and short circuit current is switched off at the moment when time delay of protection operation with acceleration is over, there made is a conclusion on switching on of RAS network point switch at short circuit due to RAS prohibition failure and its following disengagement.

EFFECT: extension of functional capabilities by way of obtaining information on prohibition failure of reserve automatic switching in ring network line.

2 dwg

Description

The invention relates to the automation of electrical networks and is intended to control the failure of the prohibition of automatically turning on the reserve (ATS) in a ring network powered by different buses of a two-transformer substation, and the ATS point is equipped with devices for prohibiting the inclusion of its circuit breaker for short circuit (short circuit).

There is a method of monitoring the failure of the inclusion of the point of automatic inclusion of the reserve in the ring network, powered by the buses of a two-transformer substation, which consists in fixing two inrush currents and in counting the time from the moment the first inrush current appears on the transformer tires of the main power source, which is equal to the delay time of switching on the ABP point, at the end of the countdown, the manifestation of the second surge of the operating current is controlled greater than normal or short circuit current on the buses of the backup source transformer ika power, and if they do not exist, then establish the fact of refusal enable ABP points on the ring [RF patent №2215356, publ. 10/27/2003, bull. No. 30].

The disadvantage of this method is the impossibility of using it to control the failure of the ban ATS in the line of the ring network.

The objective of the invention is to expand the functionality of the method by obtaining information about the failure of the ban ATS in the ring network line.

According to the invention, from the moment of the appearance of the first short-circuit current inrush on the tires of the transformer of the main power supply, a time countdown equal to the response time of the protection of the sectionalizing circuit breaker (CB) of the line powered by the transformer of the main power supply starts, and the moment of the first short-circuit current break is controlled and, if the moment of the end of the counted-down time, the short-circuit current is turned off, then a conclusion is drawn about the disconnection of the CB, from the moment of disconnection of the first inrush short-circuit current, a countdown starts, equal to the holding time on value of the circuit breaker of the ABP network point plus the time of the protection operation delay with acceleration of this switch, and if at the end of the shutdown time of the circuit breaker of the ABP network point the second short-circuit current surge appears on the busbars of the transformer of the backup power source, and at the end of the protection operation delay time with acceleration if the short-circuit current is disconnected, it is concluded that the circuit breaker of the ATS network item on the short circuit is turned on due to a failure of the ATS ban and its subsequent shutdown.

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 with short circuit at point 4 (see figure 1).

The circuit (see Fig. 1) contains: a power transformer 1 of the main power source, a head switch (GV) 2 lines of the main power source, CB 3 lines of the main power source, short circuit point 4, switch 5 of the network switch point ATS with a device for prohibiting ATS on short circuit , CB 6 lines of redundant power supply, GV 7 lines of redundant power supply, circuit breaker 8 bus ABR, power transformer 9 of backup power supply, short circuit current sensor (DTKZ) 10, element MEMORY 11, element NOT 12, element DELAY 13, element SINGLE-DISPLAY 14, element And 15, MEMORY lement 16, delay element 17, the monostable element 18, AND gate 19, DTKZ 20 Memory element 21, delay element 22, NOT element 23, the monostable element 24, AND gate 25, recording unit (RU) 26.

The signal diagrams at the outputs of the elements shown in figure 1 with a short circuit at point 4 (see figure 1) have the form (see figure 2): 27 - at the output of element 10, 28 - at the output of element 11, 29 - at the output of element 12, 30 — at the output of element 13, 31 — at the output of element 14, 32 — at the output of element 15, 33 — at the output of element 16, 34 — at the output of element 17, 35 — at the output of element 18, 36 — at the output element 19, 37 - at the output of element 20, 38 - at the output of element 21, 39 - at the output of element 22, 40 - at the output of element 23, 41 - at the output of element 24, 42 - at the output of element 25, 43 - in RU 26 In figure 2, in addition to diagrams of output signals, t The following are also shown: t ₁ - time of the occurrence of short-circuit, t ₂ - time of switching off the current of short-circuit, t ₃ - time of turning on the switch 5 of the network item ATS, t ₄ - time of switching off switch 5 of the network point ATS with acceleration.

The method is as follows.

In the normal mode of operation of the ring network line, switches 2, 3, 6 and 7 are turned on, and switches 5 and 8 are off, there is no short circuit at point 4, so there is no signal at the DTKZ 10 output and the circuit is in control mode.

With a stable short circuit at point 4 (see Fig. 1), a signal will appear at the output of DTKZ 10 (Fig. 2, Diagram 27, time t ₁ ). It will go to the input of the element NOT 12, while the output signal that existed before that will disappear (Fig. 2, Diagram 29). In parallel with this, the output signal DTKZ 10 will go to the input of the element. MEMORY 11, it will be remembered by him (Fig. 2, Diagram 28) and will go to the input, element DELAY 13, from the output of which he will appear after a time equal to the response time of the protection CB 3 (Fig. 2, Diagram 30, time t ₂ ). After this time, the signal will go to the SINGLE-VIBRATOR element 14, it will make one oscillation and with its signal (Fig. 2, Diagram 31) will “clear” the memory from the element 11 and go to the first input of the And element 15. At this point in time (t ₂ , see figure 2) CB 3 under the action of its protection will turn off and turn off the first inrush current short circuit, so the signal disappears from the output of DTKZ 10 (figure 2, Fig. 27). In this case, at the output of the element HE 12, a signal will again appear (Fig. 2, Diagram 29), which will go to the second input of the And 15 element. The presence of two input signals at And 15 will lead to the appearance of its output signal (Fig. 2, Diagram 32 ) This signal will go to RU 26 and will provide information in it that CB 3 has turned off (Fig. 2, Diagram 43). And also it will go to the input of the MEMORY element 16, where it will be remembered (Fig. 2, Diagram 33) and will go to the input of the DELAY element 17. From the output of this element, the signal will appear after a time equal to the shutter speed of the on-off switch 5 of the ABP network item (Fig. 2, Diag. 34, time t ₃ ) and will go to the input of the SINGLE-SELECTOR element 18. He will make one oscillation and with his signal (Fig. 2, Diag. 35) will "clear" the memory from element 16 and go to the second input of the And 19 element . At this point in time (figure 2, time t ₃ ) will turn on the switch 5 of the network item ABP the reason for the prohibition failure caused by any malfunction, therefore, at the output of DTKZ 20, a signal will appear (Fig. 2, Diagram 37), which will go to the first input of And 19 element and its signal will appear at its output (Fig. 2, Diagram 36 ) This signal will go to RU 26 and there will appear information on the inclusion of the circuit breaker 5 of the ABP network item in the short circuit due to a failure of the ban, and the signal will go to the input of the MEMORY 21 element, where it will be remembered (Fig. 2, Diagram 38) from the output of this element the signal will be received at the input of the DELAY 22 element and will be delayed in it for a time equal to the time of the protection actuation with acceleration of the switch 5 of the ABP network item (Fig. 2, Fig. 39). Having left the last element, the signal will go to the SINGLE-VIBRATOR 24 element, it will make one oscillation (Fig. 2, Diagram 41) and with its signal “discard” the memory from the Element 21 and will go to the first input of the And 25 element. At this point in time (Fig. 2, time t ₄ ) the switch 5 of the ABP network point will turn off with acceleration, while the short-circuit current will disappear and the signal will disappear again at the output of element NOT 23 (Fig. 2, diagram 40), which disappears when the short-circuit current reappears. This signal will go to the second input of the And 25 element and its signal will appear at its output (Fig. 2, Diagram 42), which will go to the RU 26 and ensure that information appears in it that the switch 5 of the ABP network point has been turned off with acceleration.

Thus, the proposed method allows to obtain information about the failure of the ban ATS in the ring network line.

Claims (1)

A method for monitoring the failure to prohibit automatic switching on of a reserve (ATS) in a ring network line powered by different buses of a two-transformer substation, which consists in fixing the inrush currents and in measuring the time between them, characterized in that from the moment of the appearance of the first inrush current of a short circuit the tires of the transformer of the main power source start a countdown equal to the response time of the protection of the sectioning circuit breaker of the line powered by the transformer of the main power source, and the controller cosiness is the moment of disconnection of the first short-circuit current surge and, if at the end of the counting time, the short-circuit current is turned off, then a conclusion is drawn about the sectioning circuit breaker being turned off, from the moment of switching off the first short-circuit current surge, the time begins to be counted equal to the shutter-off time of the circuit breaker of the ABP network item plus the response protection with acceleration of this switch, and if at the end of the holding time of the circuit breaker of the ABP network item, a second short-circuit current surge occurs on the tires of the backup transformer of the power supply point, and at the end of the delay time of the operation of the protection with acceleration, the short circuit current is turned off, then they conclude that the circuit breaker of the ATS network point on the short circuit is turned on because of the failure of the ATS ban and its subsequent shutdown.

Images