RU2536813C1 - Control method of failure of activation of sectionalising switch at recovery of normal circuit of ring network - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention relates to automation of electric circuits and is intended to control the failure of activation of a sectionalising switch at the recovery of a normal circuit of a ring network. On transformer buses of the main power supply unit there fixed is the appearance of a current surge caused by a short circuit (SC) in a line fed from this transformer. At the appearance of the short circuit current surge, counting of the time is started, which is equal to the time delay of activation of an automatic transfer switch (ATS) station. Upon completion of counting of this time, the appearance of the current surge on the transformer buses of a standby power supply unit is controlled. If there is no current surge on the transformer buses of the standby power supply unit upon completion of the time counting, it means that the failure of activation of the ATS station occurred. Voltage is measured at a sectionalising point, and if it is recovered to the value at which reference automation will be actuated and shall activate the switch of this point, and in the line of the main power supply unit in the delay time of actuation of sectionalising switch (SS) and the delay time of deactivation of the switch of the ATS station no increase of operating current occurs by the value determined by a load of a reserved section, then, a sounding pulse is supplied to the line, the time is measured, during which it reaches a reflection point, the distance is calculated to this point and compared to the distance to the SS installation place, and if they are equal, a conclusion is made on the SS actuation failure.

EFFECT: enlarging functional capabilities due to control of the failure of activation of a sectionalising switch at the recovery of the normal circuit 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 the sectioning switch (CB) when restoring the normal circuit of the ring network.

There is a method of controlling the failure of the inclusion of the automatic transfer switch (ATS) in the ring network, which consists in the fact that on the tires of the transformer of the main power source, the appearance of an inrush caused by a short circuit in the line powered by this transformer is detected. When the appearance of an inrush short-circuit current begins to count down the time equal to the delay time of the inclusion of the item ABP. At the end of this time, the appearance of a current surge is controlled (the current can increase to a value of a more normal operating current, at least K3 current - an inrush current or to a short-circuit current - an inrush current) on the buses of a transformer of a backup power source. If at the end of the countdown there is no current surge on the tires of the transformer of the backup power source, then this indicates that there was a failure to turn on the ABP item [RF patent No. 2215356, cl. H02J 13/00, publ. 10/27/2003, bull. No. 13].

A disadvantage of the known method is the impossibility of using it to control the failure of the sectioning switch to turn on when restoring the normal circuit of the ring network.

The task of the invention is to expand the functionality of the method by monitoring the failure of the sectioning switch to turn on when restoring the normal circuit of the ring network.

According to the proposed method, the voltage value is measured at the sectioning point and, if it is restored to the value at which the dividing automatics will work and should turn on the switch of this point, and in the line of the main power source, through the holding time of the CB on and the holding time of the CB switch operating current to a value determined by the load of the reserved section, then a probe pulse is sent to the line, the time it takes for it to reach the reflection point is measured, you calculate the distance to this point and compare it with the distance to the installation site of the CB and, if they are equal, then make a conclusion about the failure to turn on the CB.

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 Fig. 1) contains: power transformers 1 and 2, busbar breakers 3 and 4, bus selector switch 5, head switches 6 and 7, sectional switches 8 and 9, circuit breaker 10 of the ABP network point, voltage sensor (DN ) 11, elements: MEMORY 12, DELAY 13, SINGLE-SELECTOR 14, sensor for increasing working current (DVRT) 15, elements: NOT 16 and 17, information processing unit (BOI) 18, probe pulse generator (GZI) 19, probe pulse generator (PZI) 20, the recording device (RU) 21.

The signal diagrams at the outputs of the elements shown in figure 1 have the form (see figure 2): 22 - at the output of element 11, 23 - at the output of element 12, 24 - at the output of element 13, 25 - at the output of element 14, 26 - at the output of element 15, 27 - at the output of element 16, 28 - at the output of element 17, 29 - at the output of element 18, 30 - at the output of element 19, 31 - at the output of element 20, 32 - in RU 21.

In Fig.2, in addition to the diagrams of the output signals of the circuit elements, also shown: t1 is the moment of voltage recovery at the sectioning point, t2 is the time instant of opening the circuit breaker 10.

The method is as follows.

In normal network operation, switches 3, 4, 6, 7, 8, and 9 are on, and switches 5 and 10 are off. An increase in the load in the line of the main power source can cause the voltage at the sectioning point to drop to a value at which the dividing automatics will turn off the CB 8. The loss of voltage at the ABP network point will cause the switch 10 to turn on and the circuit will switch to the redundant power mode section of the line of the main power source. When voltage is restored at the sectioning point to the value of the undervoltage relay trip, the dividing automatics will work and give a command to turn on CB 8, however it will not turn on due to a malfunction, for example, a solenoid circuit break. The restoration of voltage at the sectioning point will result in a signal appearing at the output of DN 11 (Fig. 2, diagram 22, time t ₁ ). This signal will go to the input of the element MEMORY 12, it will be remembered by it (Fig. 2, Diagram 23) and will go to the input of the element DELAY 13. From the output of this element, the signal will appear after the shutter speed of CB 8 and the shutter speed of the circuit breaker 10 (Fig. 2 , diag. 24) and will go to the input of the SINGLE-VIBRATOR element 14. It will produce one oscillation (Fig. 2, Diagram 25), this signal will “discard” the memory from element 12 (Fig. 2, Diagram 23) and will go to the second input element And 17. During the time (t ₁ - t2) the operating current in the line of the main power source should increase by a value determined by the load short redundant section, but this will not happen due to a failure to turn on the switch 8, therefore, the signal does not appear at the input of DVRT 15 (Fig. 2, Diagram 26), and the signal does not disappear from the output of the HE16 element (Fig. 2, Diagram 27 ) and will be present at the first input of element And 17. It will work (Fig. 2, Diagram 28), its signal will go to the first input of BOI 18. At the same time, from its first output (Fig. 2, Diagram 29) to the input of the GZI 19 signal will come. This signal will ensure the sending of the probe pulse (figure 2, Fig. 30) in the line of the main power source. The signal, reaching the reflection point, will return back and go to the FDI 20, and from its output (Fig. 2, Diagram 31) to the BOI 18. This element will determine the transit time of the probe pulse to the reflection point, calculate the distance to this point and compare it with a distance to switch 8. And, if they are equal, then at the second output of BOI 18 a signal will appear (Fig. 2, Diagram 29), which will go to RU 21, and there will appear information that CB 8 did not turn on .

Thus, the proposed method allows to obtain information about the failure to turn on the sectioning switch (CB) when restoring the normal circuit of the ring network.

Claims (1)

A method for monitoring the failure of the sectioning switch (CB) to turn on when restoring the normal circuit of the ring network, which consists in fixing the inrush currents and in measuring the time between them, characterized in that they measure the voltage value at the sectioning point and, if it is restored to the value at which fission automatics it will work and must turn on the switch of this item, but in the line of the main power source, after the shutdown time of turning on the CB and the shutter speed of the shutdown of the switch of the ATS point, If the working current is calculated by the value determined by the load of the reserved section, a probe pulse is sent to the line, the time it takes for it to reach the reflection point is measured, the distance to this point is calculated and compared with the distance to the CB installation site, and if they are equal, conclude the failure to turn on the CB.

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