SU1365239A1 - Arrangement for coupling two power systems - Google Patents

Abstract

The invention relates to power engineering. The purpose of the invention is to reduce the installed power of the switching equipment. The secondary windings 11,12,13 of tr-ra 1 form two systems of secondary stresses, shifted relative to each other by 90 or i 45 relative to the corresponding phases of the supply voltage

Description

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SP IsD

WITH

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neither The windings 14, 15 and 16, 17 tr-ra 2 are powered from various secondary voltage systems of tr-ra 1. At this voltage, applied to common points of the windings 14, 15 and 16,17, are shifted by an angle of 90. When switching the thyristor keys 7.8, the magnetic flux created by the windings 15, 14 in the half-core 18 changes the phase by 180.

the same happens with semi-core magnetic flux 19 when switching thyristor keys 9,10. The voltage in the windings 4 th-ra 2 is determined by the sum of the half-core flows. The phase change of the output voltage occurs depending on the change of the switching angle of the thyristor switches. 4 il.

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The invention relates to the field of electric power engineering, namely, devices designed to provide predetermined power flows between two power systems operating with differing frequencies of alternating current. ;

The purpose of the invention is to reduce the installed power of the switching equipment.

FIG. 1 is a schematic diagram of the proposed device when fully controlled thyristors are used as switching elements; in fig. 2 - the same, when using three-phase as switching elements

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artificial switching; in fig. 3 a circuit for connecting the main and additional secondary windings is deployed; in fig. 4 - curves, explaining the principle of obtaining the output voltage of the device.

A device for combining two power systems (Fig. 1) contains two three-phase transformers 1 and 2, the primary windings 3 and 4 of which are connected to buses 5 and 6 of the power systems being combined, and switching elements 7-10, made in the form of thyristor switches. Transformer 1 also contains the main 11 and auxiliary 12 and 1.3 secondary windings. Transformer 2 also contains four secondary windings 14-17, located on the half-cores 18 and 19 of the magneto-conductor of the transformer 2 and connected in series. The free ends of the windings 14-17 are connected respectively to the switching elements 7. 10. The auxiliary windings 12 and 13 of the transformer 1 are connected to the connection points of the secondary windings 14-17. The phases of the main secondary winding 11 are connected to the ends of the phases of the auxiliary secondary windings 12 and 13, adjacent to the transformer magnetic cores. one.

The device works as follows.

The secondary windings 11-13 of transformer 1 form two secondary voltage systems shifted one relative to the other by 90 or ± 45 relative to the respective phases of the supply voltage (Fig. 3). The indicated phase shift is provided by the corresponding ratio of the number of turns, viz. ,

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The windings 14-17 of the transformer 2 are fed from various secondary voltage systems of the transformer 1.: At this voltage, the voltages supplied to the common points of the windings 14-17 are in quadrature, i.e. shifted by an angle of 90 °. When switching keys 7 and 8, the magnetic flux created by the windings 14 and 15 in the corresponding half-core changes its phase by 180 °. The same happens with the magnetic flux of the other half-tars when switching thyristor switches 9 and 10, connected with windings 16 and 17. Since the primary windings 4 of transformer 2 cover both semi-cores 18 and 19, on. the voltage applied to them is determined by the sum of the magnetic fluxes of the corresponding half-cores. rfa FIG. 4 shows the voltage waveforms of both 14-15 and 16-17, as well as the output voltage of the device and 4 shows the phase adjustment process for three fixed values of the angle 9. The rest of the range up to b 360 is a further alternation of graphs. Thus, depending on the change of the switching angle ct, the phase of the output voltage changes from 0 to 360 °. The proposed device reduces the installed power of the switching elements by half.

Claims (1)

Invention Formula A device for combining two power systems containing three-phase transformers, one of which is provided with a primary winding connected to terminals for connecting the first power system and three secondary windings, the main one and two auxiliary ones, and the other is equipped with a primary winding connected by a clip for the connection of the second power system, and four secondary windings, and switching elements connected to the secondary windings of the second transformer, characterized in that, in order to reduce the installed power of the switching equipment, the beginning of the phases of the main secondary winding of the first transformer are connected in a star, and the ends each phase of the main secondary winding of the first transformer is connected to the ends of the phases of two auxiliary secondary windings located on adjacent cores of the magnetic circuit of the first transformer matora, and the core of the second transformer is split into two half-cores, with the primary windings 0 are wound on both semi-cores, on each half-core there are two secondary windings, connected in a consistent way, and each phase of the auxiliary secondary winding 5 of the first transformer, with its beginning phase-wise connected to the connection point of the secondary windings of the second transformer, and the free ends. The secondary windings of the second transformer are connected to the switching elements.