SU881949A1 - Dc voltage-to-dc voltage converter - Google Patents

Description

I

The invention relates to a converter technique, namely to a power thyristor converters of a constant voltage of one level into a constant voltage of another level.

Various types of constant voltage thyristor converters are known.

One of the known types of transducers uses the principle of frequency-pulse regulation. Such converters have special elements (nodes, circuits) that provide the quenching of thyristors 1.

However, the use of additional elements (circuits) for quenching power thyristors leads to additional losses and reduces the frequency properties of the circuit as a whole.

The closest to the proposed technical entity is a constant-voltage-to-constant-voltage converter, containing a 1 converter cell, made in the form of two thyristors connected in series between the input and outputs, and the primary winding of the drossel is connected in series with each thyristor

the connection point of which is connected via switching capacitors to the input terminals, and the secondary winding of the throttles is connected via a valve to the output terminals, in parallel with which the smoothing capacitor 2 is connected.

In such a converter, there are no special thyristor enrichment devices. Thyristors are locked in a natural way at the end of the recharging of capacitors.

The disadvantages of this device are the relatively high voltage level on the thyristors, due to the induction of two times the emf in two series-connected windings and the short time of the reverse (locking) voltage on the thyristors, which reduces the frequency properties of the circuit and degrades the weight and size characteristics.

The purpose of the invention is to expand the frequency range.

This goal is achieved by the fact that in a constant voltage converter n constant, containing a converter

a cell made in the input of two thyristors connected in series between the input. terminals, in series with each thyristor, the primary winding of the throttles is connected, the common connection point of which is connected via switching capacitors to the input terminals, and the secondary winding of the throttles is connected via a gate with output terminals, in parallel with which the smoothing capacitor is connected, in addition one is similar to a cell, with the primary windings of all chokes placed on a common magnetic core.

The drawing shows as an example the scheme of the proposed Converter, which introduced an additional two cells.

The Converter includes switching capacitors 1-6, thyristors 7-12, chokes 13, 14, windings 15-22 chokes, valves 23, 24, smoothing capacitor 25, load 26.

The device works as follows.

Thyristors are included in the sequence 7-11-9-10-8-12. During the opening time of the thyristor 7, the capacitors 1 and 2 are recharged, while in the half-period the energy on the capacitors is equal to the energy at the beginning of the half-period; the energy consumed from the network goes to increase the energy of the drossel. After the thyristor 7 is closed, which occurs after the valve 24 is opened, the energy of the throttle is transferred partially or completely from the winding 18 through the valve 24 to the output clamps. When the thyristor 11 is opened, the conditions for the passage of current through diristor 7 and 11 are not created, since there are no galvanic connections between them in the circuit. The use of two chokes reduces the voltage on the thyristors, since the voltage from the windings of the chokes 14 does not transform into the windings of the chokes 13 and vice versa.

The introduction of additional cells improves the frequency properties of the converter, since after locking the next thyristor, the reverse voltage on the thyristor is maintained

for at least two half-periods (two half-periods of operation of the thyristors of the other cells), which ensures reliable locking of the thyristor before switching on the adjacent thyristor of the same cell.

The output power (voltage, current) is controlled by varying the operating frequency. The combined effect of the separation of chokes and the introduction of additional cells provides high frequency properties of the circuit (when the recovery time of thyristors is 20-10 s, the circuit ensures reliable operation at a frequency of up to 20 kHz), which reduces the size and weight of the active elements whole

Claims (2)

Invention Formula A constant-voltage-to-constant-voltage converter containing a converter cell made in the form of thyristors connected in series between the input terminals, the primary winding of the choke switches connected in series with each thyristor, and their common connection point is connected through switching capacitors with input terminals, The secondary winding of the throttles is connected through a gate with output terminals, in parallel with which a smoothing capacitor is connected, characterized in that, in order to expand the frequency range, additionally, at least one cell is introduced, with the primary windings of all chokes placed on a common magnetic core. Sources of information taken in the audience during the examination 1. Rudenko V.S. Converting equipment, Kiev, Higher School, 1978, p. 218, fig. 4-17. 2. For Japan Japan No. 5099808, cl. H 02 M 7/515, 1976. i 4Z3 R AT f2 / / s :, Un f7 / LLdfc iL U s: / 2