RU2502173C1 - Control method of spurious trip of sectional bus switch at operation of annular network in substation standby mode - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: method consist in fixation of current surges and in measurement of time between them. Available voltage on buses and available current in the main power source line is controlled, and if voltage on buses and current in the main source line disappears, and voltage on buses of a standby power source does not disappear, a conclusion is made on spurious trip of a sectional switch of buses of a two-transformer substation.

EFFECT: enlarging functional capabilities.

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Description

The invention relates to the automation of electrical networks and is intended to control the false shutdown of the sectional bus switch during operation of the ring network in the substation backup mode.

There is a method of controlling false shutdown of a sectionalizing circuit breaker in a ring network line, 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 and in the absence of an inrush current of short circuit time equal to the holding time of the circuit breaker of the automatic reserve switching point, and at the end of the countdown of this time, the appearance of a current surge beginning of the line, and a backup power source if there is cast a current value determined by the load off the main power source line, the set of false fact partitioned off switch in the ring network line [patent RU №2378754, Cl. H02J 13/00, publ. 01/10/2010, bull. No. 1].

The disadvantage of this method is the impossibility of using it to control the false disconnection of a sectional bus switch during operation of the ring network in the substation backup mode.

The objective of the invention is to expand the functionality of the method by controlling the false shutdown of the sectional bus switch during operation of the ring network in the substation backup mode.

According to the invention, the presence of voltage on the buses and current in the main power supply line is monitored, and if the voltage on the buses and current in the main power supply line disappear, and the voltage on the buses of the backup power supply does not disappear, then a conclusion is made about the false disconnection of the bus section switch of the two-transformer substation .

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: a power transformer of the main power supply 1, an input switch (BB) of the buses of the main power supply 2, a main switch (GV) of the main power supply line 3, a section switch (CB) of the main power supply line 4, circuit breaker of the automatic reserve power-on point (ABP) 5, CB line of the backup power supply 6, GV of the backup power supply line 7, section switch of the bus station ABP 8, BB of the backup power supply bus 9, operating current sensor (DRT) 11 _} poles (DN) 12 and 13, elements NOT 14 and 15, element 16, recording device (RU) 17.

The signal diagrams at the output of the elements shown in figure 1 have the form (see figure 2): 18 - at the output of element 11, 19 - at the output of element 12, 20 - at the output of element 13, 21 - at the output of element 14, 22 - at the output of the element 15, 23 - at the output of the element 16, 24 - at the output of the element in the switchgear 17. In Fig 2, in addition to the diagrams of the output signals, also shown: t ₁ - the time of the false shutdown of the bus section switch 8.

The method is as follows.

In the substation backup mode, caused by turning off the main power supply of the transformer 1 or turning off the bus input switch 2 and then automatically turning on the section bus switch 8 at the outputs of the sensors DRT 11, DN 12 and DN 13, there are signals (Fig. 2, Diagram 18, 19, 20 respectively). At the same time, there are no signals at the outputs of elements NOT 14 and 15 (Fig. 2, diagrams 21 and 22, respectively), therefore, the circuits are in control mode.

In the case of a false shutdown of the sectional bus switch 8, which occurred due to any malfunction from the outputs of the DRT 11 and DN 12, the signals will disappear (Fig. 2, Diagram 18, 19, respectively, time t ₁ ) . In this case, there will be signals at the outputs of the elements NOT 14 and 15 (Fig. 2, diagrams 21 and 22, respectively), which will be supplied to the first and second inputs of the I16 element. The presence of voltage at the transformer of the backup power source 10 provides an output signal to the DN 13 (Fig. 2, Diag. 20) which is present at the third input of the element I. 16, therefore, at time t ₁ And 16, its output signal (Fig. 2, Diag. 23) will arrive at RU 17, ensuring the appearance of There is information that the bus section switch 8 has tripped falsely.

Thus, the proposed method allows to obtain information about the false shutdown of the sectional bus switch during operation of the ring network in the substation backup mode.

Claims (1)

A method for monitoring the false shutdown of a busbar sectional switch during operation of the ring network in the substation backup mode, which consists in fixing the inrush currents and in measuring the time between them, characterized in that they control the presence of voltage on the buses and current in the main power supply line and, if the voltage on the buses and the current in the line of the main power source disappears, and the voltage on the tires of the backup power source does not disappear, then they conclude that the bus section switch of the two-transformer bus dstantsii.

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