SU1515258A1 - A.c. power supply system - Google Patents

Abstract

The invention relates to electrical engineering and can be used to provide stable parallel operation of transformers with various external characteristics. The purpose of the invention is to enhance the functionality by including transformers with any transformation ratios and any ratios of winding resistances. This is achieved by introducing on each transformer two counter-parallel-connected valve switches consisting of diodes 4-7 and thyristors 12-15, and control units consisting of diodes 8-11, capacitors 25-27 and resistors 16-23. 1 il.

Description

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The invention relates to electrical engineering, and more specifically to devices that provide stable parallel operation of transformers with different external characteristics.

The purpose of the invention is to enhance the functionality by including transformers with any transformation ratios and any ratios of winding resistances.

The drawing shows a diagram of the proposed device ..

The device contains a single-phase transformer 1, an autotransformer 2 network 3, diodes 4-11, non-lockable thyristors 12-15, resistors 16-23, capacitors 24-27, load 28.

The device works as follows.

Redistributing the load current is carried out by changing the secondary voltage of the autotransformer 2. Increasing the secondary voltage of the autotransformer 2 leads to an increase in the current of the autotransformer and reducing the current of the secondary winding of the transformer 1. A decrease in the secondary voltage of the autotransformer 2 leads to an increase in the secondary current of the transformer 1. Thus unload any of the transformers, and the transition of any of the transformers to the energy consumer mode is excluded, the diodes do not pass reverse current.

In this case, the thyristors play the role of a key, closing only for the time of one half period of alternating current. During the first half period, the thyristor 12 is closed (the key is open), since the diode 10 is closed and there is no reverse voltage on the control electrode. During the second half period, when a small direct anode voltage is generated, the thyristor 12 is opened through the resistor 16 and the diode 10 remains open until the alternating load current decreases to zero. After this, the voltage on the thyristor becomes reverse again and it is locked.

Similarly, the thyristor 13 closes and opens, but into other half-liriods, i.e. thyristor 13 is closed

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while thyristor 12 is open. The transformer secondary winding in the first half of the period passes through open diode 6, load 28, open thyristor 13, and in the second half of the period through diode 4, load 28 and open thyristor 12.

Shunt resistors 17, 19, 20,22 are included between the cathode and the control electrode of the unlocked thyristors 12-25. The thyristor control electrode circuits include capacitors 24–27 for opening thyristors at the lowest forward anode voltage. Resistors 16,18,21,23 limit the forward current of the control electrode.

Thus, the proposed device allows to use for parallel operation transformers with different external characteristics and to redistribute the load between them.

The use of the device leads to a decrease in the installed power of the transformers, bringing it closer to the calculated one, since it allows switching on the parallel operation of transformers with different rated power. The device can be used to turn on parallel operation, several single-phase transformers and autotransformers, as well as to turn on three-phase transformers. For parallel operation of three-phase transformers, it is necessary to turn on each phase of the secondary winding according to the proposed scheme.

Claims (1)

Invention Formula An alternating current power system containing two transformers with any power ratio, I distinguish from P1a so that, in order to expand the functionality by switching on transformers with any transformation ratios and any winding resistance ratios, two per parallel transformers are inserted into each transformer valve key with control units, with the keys consisting of a diode and a thyristor, and each key is connected by one output to the first and second, the outputs of the secondary nds) d) anformator, respectively, and the other key outputs belonging to the transient 51515258 formatters are combined and form windings of the transformer, respectively, Vygeody for connecting the load, the block-common point of connection of the resistors of the control junction is made in the form of a diode, a dinene with a control electrode of the tyrncapacitor and two in series with a capacitor and a capacitor, the second output included resistors, one of which is connected to the cathode of the diode connected to the thyristor cathode, control unit drud, primary windings gim - through the cathode-anode of the diode to the per-transformers are connected to the terminals voyom and second pins secondary ob-to connect to the power source.