SU1598033A1 - Device for protecting star-connected static capacitor bank with insulated neutral - Google Patents

Abstract

The invention relates to power engineering, in particular, to the technique of relay protection of static capacitor batteries (BSK) against internal damage. The purpose of the invention is to increase the sensitivity and enhance the functionality. This is achieved by including a voltage transformer 7, an adjustable 5 and an unregulated 6 capacitive blocks, a maximum voltage relay 8, a phase-equalizing circuit 9. The voltage on the maximum voltage relay 8 is absent in the normal operating mode. If an internal fault occurs in one of the BSK phases, its resistance changes, resulting in an uncompensated voltage on the maximum voltage relay. 1 il.

Description

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The invention relates to power engineering, in particular to relay protection of capacitor batteries.

The purpose of the invention is to increase the sensitivity and enhance the functionality.

The drawing shows the proposed device.

The device includes a capacitor battery 1, parallel to each phase of which voltage transformers 2-4 are connected, the secondary windings of which are connected in series with the neutral points of the adjustable capacitive three-phase unit 5 and the unregulated three-phase capacitive unit 6 connected to the secondary windings of the three-phase bus transformer 7, and an 8-maximum voltage relay, in parallel with which is connected the first pin of the phase-matching circuit 9. To the second, third, and fourth pin of the phase-equalization ayuschey pofezno circuit 9 connected secondary windings of a three phase transformer 7 bus voltage.

The device works as follows.

In the normal operating mode, the voltage in the dissection of the open triangle of the secondary windings of transformers 2-4 voltage, due to the inequality of the capacitances of the phases of the battery 1 static capacitors, is compensated by a correspondingly adjusted voltage between the neutral points of the capacitive three-phase adjustable 5 and unregulated 6 blocks. Thus, the voltage on the maximum voltage relay 8 is missing. If an internal fault occurs in one of the phases of the capacitor battery 1, its resistance changes, resulting in an uncompensated voltage on the maximum voltage relay 8. Upon the coincidence of this voltage in the motor phase with one of the mains voltage, a signal appears at the corresponding output of the phase-matching circuit 9. When the voltage on the relay 8 exceeds the maximum voltage level of its setting

the relay is activated and disconnects the battery from the network.

Thus, the proposed device can be applied in the technique of diagnostics and protection of capacitor batteries, which makes it possible to reduce the damage from electric power losses in the networks, the damage from the deterioration of the quality of electric power, Device for protection of a battery of static capacitors, assembled into a star with insulated neutral, containing three voltage transformers, the primary windings of which have terminals for 5 connections in parallel to the corresponding phases of the battery, secondary windings transformer moat voltage connected to open delta, a first terminal of which is connected the first terminal of relay .k 0 maximum voltage, characterized in that, in order to increase the sensitivity and expansion of functionality, it is further introduced adjustment and 5 uncontrolled three-phase capacitive. blocks, bus three-phase voltage transformer, the primary winding of which has terminals for connecting to the corresponding phases of the supply network of the static capacitor battery, the second output of the maximum voltage relay is connected to the neutral terminal of the unregulated capacitive three-phase unit, the phase terminals of which are connected to the phase terminals 5 an adjustable three-phase capacitive unit connected to the secondary winding of a three-phase bus voltage transformer having a star connection, a neutral output of an adjustable The three-phase capacitive unit is connected to the second output of an open triangle, the first output of the newly introduced phase-matching circuit is connected to the first voltage relay terminal, the second, third and fourth 45 terminals of the phase-matching circuit are connected in phase to the secondary winding of the voltage transformer, the output of the overvoltage relay is included in the battery disconnect circuit, and the three 50 phase outputs of the comparison circuit are phased in the alarm circuit.

Claims (1)

Claim Device for protecting a battery of static capacitors assembled in an star with an insulated neutral, containing three voltage transformers, the primary windings of which have terminals for connecting in parallel to the corresponding phases of the battery, the secondary windings of the voltage transformers are connected in an open triangle, the first terminal of which is connected to the first output of the maximum relay voltage, characterized in that, in order to increase sensitivity and expand functionality, it is additionally introduced adjustable and unregulated capacitive three-phase units, a bus three-phase voltage transformer, the primary winding of which has terminals for connecting to the corresponding phases of the power supply network of the battery of static capacitors, the second terminal of the maximum voltage relay is connected to the neutral terminal of the unregulated capacitive three-phase unit, the phase terminals of which together with the phase terminals of the adjustable three-phase capacitive unit connected to the secondary winding of a three-phase busbar voltage transformer having star divergence, the neutral terminal of the adjustable three-phase capacitive block is connected to the second terminal of the open triangle, the first terminal of the newly introduced phase comparison circuit is connected to the first terminal of the voltage relay, the second, third and fourth terminals of the phase comparison circuit are phase-connected to the secondary winding of the voltage bus transformer, while the output of the maximum voltage relay is included in the battery disconnect circuit, and the three outputs of the phase-balancing circuit are phase-connected in the alarm circuit.