SU1456913A1 - Device for testing switches for cutting-off capacitive current - Google Patents

Abstract

This invention relates to electrical engineering, which can be used to test high-voltage circuit breakers in the capacitive load-off mode. The purpose of the invention is to expand the functionality of the device by playing

Description

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The invention relates to electrical engineering, in particular to the field of testing high-voltage switches in the mode of disconnecting a capacitive load.

The purpose of the invention is to expand the functionality of the device by reproducing the operating conditions of the switch in a real network when the filter compensating circuit is disconnected.

The drawing shows a fundamental device schema.

The device contains a charging voltage source 1, an oscillating circuit that reproduces the current (and voltage) of an industrial frequency, consisting of series-connected sections (according to the number N of reproducible harmonics), each of which is formed of series-connected capacitor banks 2, reactors 3 and 4 and the inclusion elements 5, for example spark gaps. The capacitor battery 2 is combined in a series circuit and form an oscillating circuit capacitor battery. The switching elements 5 are connected in series with capacitors 6, the capacity of which is 2-3 times less than the capacitance

These capacitor batteries 2. In each circuit, part of the reactor 3 is shunted by an additional disconnecting element 7, for example, a fuse, in addition, parallel to the part of each reactor 3 and 4, an additional commutation element 8, for example, a disconnector, is turned on. In the first section from the low-voltage output of the capacitor battery, reactors 3 and 4 are connected between the ungrounded leads of the capacitor battery 2 and the switching element 5.

Parallel to the capacitor battery is connected to the circuit of the sequence. connectable disconnectable capacitor 9 ,. The second reactor 10, the test switch 11, which is the main disconnecting element of the first reactor 12, reproducing the inductance of the source and the separator i 3. Parallel to the second reactor 10, the control circuit of the transition voltage from the filter side is switched a capacitor 14 and a second resistor 15. Parallel to the first reactor 12, a regulator circuit comprising the first capacitor 16 and the first resistor 17 is turned on

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vanilla transitional reducing to the yarn from the source. Parallel to the separator 13, an auxiliary switching element 18 is connected, for example, a trigatron, the control electrode of which is connected via a second capacitor i 9 to a high-voltage output of a series circuit of switching elements 5.

The device works as follows.

In the current shutdown mode with harmonic components prior to the experience, the test switch 11 and the tripping elements 7 are closed, and the switching elements 5, the separator 13 and the switching element 18 are open. In addition, in one or several circuits, the number of which depends on the number and amplitude of reproducible current harmonics, additional switching elements 8 are closed. From the source 1 of the charging voltage, the capacitor battery 2 and the switchable capacitor 9 are charged by the voltage of the same polarity determined by the voltage class of the test switch, the number of breaks tested and the test mode, after which the separator 13 is turned off.

Zar d. the capacitor 9 is continued to a value determined by the ratio of its capacitance values, capacitor bank capacitance and inductance of reactors 10 and 12, after which the source 1 of the charging voltage is turned off. Then, a command is issued to turn off the test switch 11 and, after a predetermined time, to turn on the capacitor battery 2 connected to the grounded terminal of the switching element 5, for example, a controlled spark gap. After the breakdown of the controlled spark gap 5, the zero potential is transmitted through the capacitor 6 to the lower electrode of the second switching element, the spark gap 5, and the voltage across it almost doubles, which ensures reliable breakdown of it.

After the breakdown of the second spark gap 5, the charge voltage of three batteries 2 minus the voltage drops on the capacitors 6, the magnitude of which is chosen, for example, from the condition

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doubling the voltage at each subsequent interval 5. Similarly, the remaining spark gaps are punctured 5. The last is caused by the switching-on element 18, the ignition of which is provided by the voltage on the reactor 4, which developed after the breakdown of the spark gap 5 in the last section, in 10 circuits with open the first harmonic current flows through the switching elements 8, and the current of higher harmonics flows in circuits with closed switching elements 8. In accordance with the magnitudes of the currents in each of the oscillatory circuits, the voltage on the capacitor battery 2 has the main and harmonic components. If the switch is tested 20 in the shutdown mode of the filter-compensating devices, the resistance of the circuit formed by the capacitor 9 and the reactor 10 at the harmonic frequency of this filter is close to zero, and through the 25 switch 11, apart from the current of the first harmonic, this harmonic component .

After the current is cut off by the switch 11, the capacitor 9 remains charged 30 to a voltage equal to the sum of the voltages of the capacitor bank 2 and reactors 10 and 12. This voltage has a high-frequency component whose frequency is determined by the inductance of the second reactor 10 and the capacity of the third the capacitor 14, acts on the switch from the filter-compensating device. From the source side, after a high-frequency process of voltage recovery, determined by the chain formed by the first resistor 17 and the first capacitor 16, the switch is affected by the damped voltage of the oscillating circuit. If the disconnection of the capacitor 9 causes a significant increase in the frequency of the main harmonic against the industrial one, the disconnecting element 7 desmounts 50 of the inductance in the corresponding circuits. After a period of voltage of the industrial frequency, almost double the voltage of the charge of the capacitor battery 55 is applied to the switch.

Thus, the operating conditions of the test switch in the proposed device are close to the conditions of its operation in a real network.

51If you close all switching elements of 8 oscillatory circuits, the device allows you to investigate the behavior of a switch (for example, a current cutoff) on one harmonic component. The voltage on the switch in this case is restored with the frequency of this component.

When testing in the mode of disconnecting the capacitive current of industrial frequency, the switch 11 and the disconnecting elements 7 are closed, the switching-on elements 5, the separator 13 and the switching elements 8 are open, and the reactor 10 is short-circuited .. After giving the command to turn off the test switch 11 and turn on the controlled spark gap 5 the remaining spark gaps are triggered.

Thus, in the proposed device, the conditions of the switch operation in the real network are reproduced when the filter-compensating circuits are disconnected, i.e. device functionality is expanded.

Claims (2)

1. Device for testing switches for switching off capacitive current, containing a source of charging voltage, switchable capacitor, first reactor, resistor and capacitor, separator, auxiliary switching element, second capacitor, additional switch element, second and third reactors and a capacitor bank, first the lining of which is grounded and connected to the first output of the source of the charging voltage and the first facing of the switchable capacitor, the second facing of which is connected to the first output of the test subject switch, the second output of which is connected to the second output, the source of the charging voltage, the first output of the first reactor and the first facing of the first capacitor, the second facing of which through the first resistor is connected to the second output of the first reactor and the first outputs of the auxiliary switching element and the separator, the second outputs which are interconnected, and the ignitions of the auxiliary switching element electrode are connected to the first plate of the second capacitor. 69136 The second plate of which is connected to the first terminals of the second reactor and an additional switching element, characterized in that, in order to expand its functionality, the number of reproducible harmonics 2N of additional switching elements, N additional switching elements, N capacitors are added to it, 2N - 2 reactors, N - 1 capacitor banks and N - 1 additional switchgear cells, forming 5 oscillatory circuit of the same type of cells, in each of which the first facing of the K-th capacitor battery is connected to the second output (2K - 1) of the reactor and the first output (2K - 0 1) of the second switching element, the second output of which is connected to shunting terminal (2K - - 1) of the reactor, the second lining of the capacitor battery connected to the first highways of the 2K reactor 4K-GO additional disconnecting element and 2K additional switching element, the second terminal of which is connected to the shunt output 2K - GO of the reactor, the additional shunting output of which is connected to the second output of the K-th additional disconnecting element, and the second output of the 2K-GO reactor is connected es with the second inlet of the K-th additional switching element and the first lad of the K-th capacitor, the second plate of which is connected to the first output of the (2K + 1) -th reactor and the first output of the (K + 1) -th additional switching-on element (K + 1) cell, the second terminal (2K + 1) of the reactor of which is connected to the first terminal of the 2K-GO reactor of the K-th cell, and 45 in the last cell of the oscillating circuit the first output of the (2N - 2) -th reactor. Is connected to the second plate of the (N - 1) -th capacitor of the (N - 1) -th cell, the first output of the (2N .- 1) -th 50 additional switching element and with the first output of the (N - 1) -th additional switching element, the second output of which is connected to the first capacitor bass of the container, the second facing of which is connected to the first output (2N-3) -ro of the reactor (N - 1) cell and the first conclusions of the third reactor, N-ro additional otkpyuchtsmego element 714569138 and 2n-ro additional commute 2. The device according to claim 1, about tl of a storing element, the second output of which is connected by the fact that a third secondary reactor is additionally connected to the shunt terminal; a second reactor is additionally inserted, an additional shunt reactor, the fourth reactor and the third connected terminal of which is connected with the second facing the second pin of the N-ro additional disconnectable capacitor is connected disconnecting element, and the second one with the first output of the fourth reactor water from the third reactor is connected by the first facing of the third condensate to the second output of the (2N - 2) th reactor, the second, the second facing of which is connected to the shunt terminal of which is connected. the first output of the second resistor, the second with the second output (2N - 1) -th additional output of which is connected to the second output portable commutating element of the fourth reactor and the first output of the switch being tested.