SU838883A1 - Device for electric power supply of users - Google Patents

Description

(54) DEVICE FOR ELECTRICAL SUPPLY OF CONSUMERS

one

This invention relates to electrical engineering, namely to power supply circuits.

A known power supply scheme for consumers who do not allow an interruption of power supply, in which consumers work in parallel from independent power sources, and intersectional reactors 1 are installed in consumers.

The closest to the proposed technical entity is a device for power supply to consumers, not allowing interruption of power supply, in which consumers work in parallel, containing independent power sources, a dual reactor 2 is installed at the feed inlet of each of which.

The disadvantages of these devices is that the parallel operation of consumers leads to a significant increase in short circuit parameters and the associated decrease in the stability of electrical equipment operation due to feeding short circuit points from both power sources. In addition, short circuits on one of the power sources or on one

From the sections they cause a significant decrease in the voltage on the other section, and this leads to the relaxation of transients and a decrease in the stability of the work of the consumers in both sections. The presence of reactors only at the inputs or only the intersectional section does not completely exclude the feeding of the short circuit from an intact power source.

The purpose of the invention is to reduce the short circuit parameters and increase the residual voltage on the intact

0 sections by drastically reducing the make-up of a short circuit from an intact power source.

This goal is achieved by the fact that the device for power supply to consumers without interruption of power supply, containing independent power sources, at the power input of each of which is installed a double reactor, one branch of which is connected to the consumer buses, is equipped with a switch installed between the second branches of the reactors.

In addition, the device is equipped with an additional switch installed

between the power supply inputs from the side of their connection to the reactors.

Additional switches are installed between the inputs of the second branches of the reactors and the tires.

FIG. 1, 2 is a schematic diagram of a two-section switchgear; in fig. 3, 4 - power supply scheme for consumers from independent sources; in fig. 5 is a power scheme from n independent sources.

The module contains switches 1 and 2 of the feed ports, section switches 3 and 4, twin reactors 5 and 6. Branches 5 a and 6 a are used as linear reactors. Branches 56 and 66 are used as intersection ion reactors. In normal mode, switch 3 is on, and switch 4 is off. If a short circuit occurs on one of the sections, switch 1 or 2 turns off and simultaneously switches off switch 3. If a short circuit occurs in the supply mains, the supply current from another source is limited by the resistance of the branches 56 and 66. At the same time, the switch 1 or 2 should turn off and turn on switch 4. Switch 3 in this case is not turned off. The same happens when the voltage disappears at one of the sources. After turning off switch 1 or 2 before turning on switch 4, the residual voltage on the section that lost operating power depends on the load resistance ratio and external network resistance, including both branches of the dual reactor. Switch 4 is turned on for the purpose of increasing the voltage on the sections that have lost their working power.

In this scheme, the switch 3 is wound around the current briefly in emergency mode, therefore it can be selected for a smaller rated current than the switches 1, 2 and 4.

In another embodiment of the switchgear circuit (Fig. 2), switches 7 and 8 are installed instead of switch 4. In the event of a short circuit, switch 1 or 2 is turned off and switch 7 or 8 is turned on, respectively. In this case, both sections are powered from two branches dual reactor. As the currents in the branches of the dual reactor are directed oppositely, the resistance of the reactor is halved and the voltage in both sections increases. This principle provides power supply to consumers from any number of independent power sources.

The scheme (Fig. 5) of the power supply from n independent sources contains switches 1, 2 supply inputs of the 1st and nth sources, intersection switches 7 and 8 of the 1st and nth sources, dual reactors 5, sections of consumers 9, 10, switches 4, automatically shunting

dual reactors when disconnecting the appropriate power sources.

The device works as follows

In normal mode, switches 1, 2,

7 and 8 are on, and switches 4 are off. Consumers are fed from working power sources through one of the branches of the respective dual reactor. In other branches of dual reactors with equal or small voltage fluctuations, there is no current. With significant

by varying the voltage of any source, the surge current is sharply limited by the resistance of these branches. In the event of a short circuit on any section of consumers, the current for charging a short circuit point from other power sources is also sharply limited by the resistance of the branches of the twinned reactor, and is often absent. In most cases, a short circuit on any section of consumers practically does not reflect on the work of other sections of consumers. In the event of a short circuit on any section 9 and 10, the switches 1, 2, 7 and 8 are turned off. In a short circuit on any power source, the switch 1 of this source is turned off and the switch 4, shunting the dual reactor is turned on. The same happens when the voltage disappears at any power source. After turning off switch 1 before turning on switch 4 on sections,

Q has lost your working power, the voltage is low. Its value depends on the ratio of the load resistance and the resistance of the external network, including both branches of the dual reactor. If synchronous motors are included in the load, then

5, the residual voltage is increased due to the action of a voltage boost. After turning on the switch 4, the voltage is restored.

The proposed parallel operation of consumers significantly reduces the short circuit parameters and increases the residual voltage on one of the sections during a short circuit on the other section. This reduces the requirements for thermal and dynamic stability of the electrical equipment of sections, to its switching capacity. The performance requirements of the relay protection and automation devices are also reduced, allowing the use of conventional type switches, commercially available. All this. Gives significant

0 economic effect, which can be determined only in each case. The proposed device ensures reliable operation of consumers who do not allow interruption of power supply.

Claims (2)

5 Formula of Invention I. A device for power supply to consumers who do not allow an interruption of power supply, containing independent power sources, at the feed input of each of which a dual reactor is installed, one branch of which is connected to the consumer buses, characterized in that, in order to limit the short-circuit currents during a short circuit to sections of consumers' boxes and an increase in residual voltage on intact sections of ladders; it is equipped with a switch installed between the second branches of the reactor. 2. The device according to claim 1, characterized in that it is provided with an additional switch installed between the inputs of 3 power sources on the side of connecting them to the reactors. 3. A device according to claim 1, characterized in that additional switches are installed between the terminals of the second branches of the reactors and the women. Sources of information taken into account during the examination 1. G. Lisovsky and M. Kheifets. Main circuits and electrical equipment of substations of 35-750 square meters. M., “Energie, 1977, p. 352. 2.Dvoskin L.I. Arrangements and designs of high voltage switchgear. M.-L., SEI, 1960, p. 17  4k ./ S 2