SU1753543A1 - Multifeeder electrical engineering ac plant - Google Patents

Abstract

Usage: a device for the distribution of electricity in industrial process plants, vehicles, residential premises. Summary of the Invention: Inclusion in Power Supplies / - c. - connecting circuits in series with the needs of power statically isolating capacitors 20,21,22; connection to the sections of the circuits after the capacitors, current leakage monitoring devices 23,24,25, operating on the principle of superimposed operating AC circuit provides the selectivity of disconnecting the feeder in the event of damage to the insulation of its current-carrying parts relative to the ground, regardless of whether the neutral of the power transformer supplying electrical equipment is grounded or isolated It prevents the feeder from being switched on with a feeder with damaged insulation. The remaining feeders with intact Isolation in this case remain in operation. 1 il. with s

Description

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The invention relates to electrical engineering, in particular, to electric power distribution devices in industrial process plants, vehicles, housing, and other electrified objects.

The aim of the invention is to ensure uninterrupted power supply to consumers and selectivity of protection against earth fault in both networks with isolated and networks with grounded neutral power supply transformer /

This goal is achieved by the fact that in the circuit of each feeder in series with the contacts of power switching devices on the consumer side, for example, the stator windings of electric motors, power separation static capacitors are connected, to the output terminals of which are connected to the consumers side leakage current control devices current, comparison and output blocks.

The drawing shows the installation diagram.

The installation contains three feeders. It may contain a larger number of feeders, the numerical value of which in each specific case is determined by technical and economic calculations.

The installation contains a three-phase current input 1 of alternating current, power taps 2,3,4 for the transmission of electricity to consumers power switching devices 5-10, blocks 11-16 of switching control devices and taps 17, 18 and 19 for supplying electricity to control units , power static isolating capacitors 20-22, devices 23-25, containing sources of applied direct current, units compared to the setpoint, and output units of alternating current consumers, for example, electric motors 26, 27, and 28.

Each power static separation capacitor 20-22 is connected in series with the consumer.

Some like poles of the same name, for example, negative ones, leakage current control devices 23, 24 and 25 are grounded, other poles of the same name, for example, positive ones, are connected to power current-carrying conductors, through which electric power is transmitted to consumers. The connection is located on the section of power current-carrying lived between power statistical separation capacitors 20,21 and 22 and power static separation capacitors 20,

21 and 22 and power switching devices 8, 9 and 10.

The power contacts of the power switching devices 5 and 8 are closed to supply electricity from the current lead 1 to the consumer 26; to the consumer 27 - devices b and 9; to the consumer 28 - devices 7 and 10.

If during installation operation at any feeder, in the section of the power current-carrying circuit placed after the power static coupling capacitor in the direction of power transmission from the current lead 1 to the consumer, the resistance of the insulation relative to the ground decreases to an unacceptable value the corresponding leakage current control device will flow current, which will cause a signal to the control unit to shut off the power switching device. With an unacceptable reduction in the insulation resistance of the power circuit section after the capacitor 20, the leakage current monitoring device 23 sends a signal to the control units 11 and 14 to shut off the power switching devices 5 and 8. The devices 6-10 will remain on, and the consumers 27 and 28 - in work.

If there is an unacceptable reduction in the insulation resistance in the area after the capacitor 21, the devices 6 and 9 will be disconnected by the signal of the device 24, the devices 5, 7, 8 and 10 will remain in operation.

By reducing the insulation resistance in the area after the capacitor 22, the devices 7 and 10 will be disconnected according to the signal of the device 25, the devices 5, 6, 8 and 9 will remain in operation.

In the case of an unacceptable reduction of the insulation resistance in the circuit section after the static capacitor, in a de-energized state of any feeder, turning on the device 8 or 9, or 10 will result in the signal 23, or 25, respectively, being disconnected to turn off the device 8 or 9, or 10 and to prevent devices from turning on 5 or 6 or 7.

Thus, the inclusion in the power supply circuits in series with the consumers of the power static coupling capacitors, power switching devices, connection to the sections of the circuits after the static capacitors, current leakage monitoring devices operating on the principle of operating DC current, provides the selectivity of disconnecting the feeder in case of damage to the insulation of its current-carrying parts relative to the earth, whether it is grounded or isolated neutral power transformer supplying

Claims (1)

the electrical installation, prevents the inclusions with the installation and the output units, and the voltage supply of the feeder with the damaged is also capacitors, which is characterized by isolation. The rest of the feeder system, in order to provide uninterrupted isolation, remains the power of consumers and the selectivity of work against earth fault protection both in the Formula for the Invention of a Network with Insulated Neutral, and in Multi-Feeder Electrotechnical Network with Dead-Grounded Neutral, AC power supply, containing capacitors included in each no-feeder installed on each feeder, is therefore with the contacts of power cables, power switching devices C10 switching devices with stor control units, the inputs of which are sub-consumer, and the control device inputs are connected to the outputs of the leakage current control devices connected to the leak output terminals, which include source terminals for the capacitors on the side of the consumed direct current, Biteley.