RU2536812C1 - Control method of failure of deactivation of sectionalising switch of buses of two-transformer substation at recovery of normal circuit of electric power supply of ring network - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention relates to automation of electric networks and is intended to control failure of deactivation of a sectionalising switch of buses of a two-transformer substation at the recovery of a normal circuit of electric power supply of a ring network. Appearance of voltage on buses of the main power supply unit is controlled, and if it appears, counting of the delay time of deactivation of the sectionalising bus switch is started; with that, reduction of operating current consumed from a standby power supply unit by a value determined by the load of the reserved line is controlled; and if no reduction of operating current occurs by the end of the time counting, a conclusion is made on the failure of deactivation of the sectionalising bus switch of the two-transformer substation at the recovery of the normal circuit of electric power supply of the ring network.

EFFECT: enlarging functional capabilities by receiving the information on the failure of deactivation of the sectionalising bus switch of a two-transformer substation at the recovery of the normal circuit of electric power supply of the ring network.

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Description

The invention relates to the automation of electrical networks and is intended to control the failure of disconnecting a sectional bus switch of a two-transformer substation when restoring a normal power supply circuit of a ring network.

There is a method of monitoring the failure of turning off the automatic transfer switch (ATS) point when the circuit breaker is switched on for a stable short circuit (SC) in the ring network, which consists in the fact that from the moment of the inrush of the short circuit on the transformer buses of the main power source, a time equal to the exposure time is counted operation of the ABP network item, plus the response time of the protection of its circuit breaker. At the same time, the occurrence of a fault inrush current on the tires of the backup power supply is controlled, and if it appears after turning on the switch of the ATS point switch, and at the end of the countdown of the total time, the inrush of a short-circuit current does not occur, then the fact of failure of disconnecting the ATS point when its breaker is turned on is established stable short circuit in the ring network [patent RU 2304339 C1, cl. H02J 13/00, publ. 08/10/2007, bull. No. 22].

The disadvantage of this method is the impossibility of using it to control the failure of disconnecting a sectional bus switch of a two-transformer substation when restoring a normal power supply circuit of a ring network.

The objective of the invention is to expand the functionality of the method by obtaining information about the failure to turn off the sectional bus switch of the two-transformer substation when restoring the normal power supply circuit of the ring network.

According to the proposed method, the appearance of voltage on the tires of the main power source is controlled, and if it does, then the off-delay time of the sectional bus switch is counted down, while the decrease in the operating current consumed from the backup power source is controlled by a value determined by the load of the reserved line, and if by the end of the countdown, a decrease in the operating current did not occur, then they conclude that the sectional bus switch of the two-transformer substation was turned off when it was restored and a normal power supply circuit of the ring network.

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.

The circuit (see Fig. 1) contains: a power transformer 1 of the main power source, an input switch 2 of the bus of the transformer of the main power source, a head switch 3, a line of the main power source, a section switch 4 of the line of the main power source, a switch 5 of the ATS network point, section switch 6 lines of the backup power supply, head switch 7 lines of the backup power supply, bus switch 8, input switch 9 of the bus transformer of the backup power supply, power transformation Op backup power supply 10, a voltage sensor (DN) 11, elements: a memory 12, a delay 13, a monostable multivibrator 14, the sensor reducing the operating current 15, NOT 16, AND 17, recording unit (RU) 18.

The signal diagrams at the outputs of the elements shown in figure 1, have the form (see figure 2): 19 - at the output of element 11; 20 - at the output of element 12; 21 - at the output of element 13; 22 - at the output of element 14; 23 - at the output of element 15; 24 - at the output of element 16; 25 - at the output of element 17; 26 - in RU 18. In addition to the output signals, FIG. 2 also shows: t ₁ - the instant of occurrence of voltage at the transformer 1 of the main power source, t2 - the instant of disconnection of CB 8.

The method is as follows.

In normal operation of the ring network, switches 2, 3, 4, 6, 7, and 9 are turned on, and switches 5 and 8 are turned off. The disappearance of voltage on the transformer 1 will lead to the opening of circuit breaker 2 and the sectional switch 8. The circuit will switch to substation backup mode and the ring network will be supplied from the backup power source of transformer 10. The absence of voltage on transformer 1 ensures that there is no output signal on DN 11 ( figure 2, diagram 19, time t ₀ ), therefore, the circuit will be in control mode.

When voltage appears on the transformer 1 at the output of DN 11, a signal will appear (Fig. 2, Diagram 19, time t ₁ ), which will be received at the input of the MEMORY 12 element, where it will be remembered (Fig. 2, Diagram 20) and will be transmitted to the input of the DELAY element 13. From the output of this element, the signal will appear after the shutdown dwell time CB 8. After this time, the signal (Fig. 2, Diagram 21) will go to the input of the SINGLE VIBRATOR 14. It will produce one oscillation (Fig. 2, Diagram. 22) and with its signal, it “discards” the memory from element 12 (Fig. 2, Diagram 20) and arrives at the first input of element And 17. And if ST 8 for any reason, the malfunction does not turn off, then at the output of the DURT 15 by the time t _{2 the} signal does not appear (Fig. 2, Diagram 23) (a decrease in the operating current consumed from the backup power source of the transformer 10 does not occur because . power scheme has not changed). In this case, at the output of the element NOT 16 there will be a signal (Fig. 2, Diagram 24), which is fed to the second input of the And17 element. It will work (Fig. 2, Diagram 25) and its output signal, arriving at RU 18, will provide the appearance in it of information about the failure of disconnecting CB 8 (Fig. 2, Fig. 26).

Thus, when using the proposed method, it is possible to obtain information about the failure of disconnecting the sectional bus switch of the two-transformer substation when restoring the normal power supply circuit of the ring network.

Claims (1)

A method for monitoring the failure of disconnecting a sectional bus switch of a two-transformer substation when restoring a normal power supply circuit of a ring network, which consists in fixing the inrush currents and in measuring the time between them, characterized in that they control the appearance of voltage on the buses of the main power source, and if it appears, then they start counting the shutdown delay time of the sectional bus switch, while controlling the decrease in the operating current consumed from the backup power source by a value of redelyaemoe redundant load line, and if the end of the countdown operating current reduction has not occurred, then conclude refuse off section switch two-transformer substations, busbar when restoring normal power supply circuit for a ring network.

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