SU782077A1 - Dc-to-dc voltage - Google Patents

Description

(54) CONSTANT VOLTAGE CONVERTER

one

The invention relates to a converter technique and can be used to control the current of consumers requiring a wide range of regulation and a low level of current ripple with minimum weight and dimensions of the converter.

DC / DC converters are known that use the principle of parallel capacitor switching of thyristors I and 2.

The disadvantages of such converters include the dependence of the switching capacity on the parameters of the power supply and the load, the relatively low conversion frequency.

The closest to the technical essence of the present invention is a DC / DC converter, which contains a single-phase thyristor bridge with a capacitor in the AC diagonal, connected in series with the load 3.

The disadvantage of such a converter is the limited range of current control due to output ripple

PERMANENT

current at low frequencies switch. Thyristors

The purpose of the invention is to expand the range of current control at given low values of current pulsations and minimum weight and dimensions of the converter.

/ Set goal Achieved by the fact that, in a DC / DC converter, a single-phase 1-string bridge contains a bridge in the alternating current diagonal of which an capacitor is turned on, and the diagonal of the direct current is connected to positive input and output terminals, and the output terminals are backed by reverse valve, parallel to the diagonal of the direct current of the bridge under the Tyuchen,

 at least one additional chain formed by two thyristors, between. , do the common point of the thyristors of the first additional chain and the output of the bridge diagonal The first additional is connected

20 capacitor, and between the common points of the thyristors of adjacent additional chains, additional capacitors are also included. Add 1 capacitors can

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782077

| 5years on and YaE I am waiting for common points - thyristors in non-adjacent chains, including chains of thyristors of the bridge.

The drawing shows a schematic diagram of a DC / DC converter with one additional chain of series-connected thyristors.

The converter contains a main thyristor bridge consisting of thyristors 1, 2, 3, 4 and capacitor 5 in the diagonal of alternating current. A string of two series-connected thyristors 6, 7 is connected to the DC diagonal. The middle point of the additional circuit of thyristors 6.7 and one of the terminals of the AC diagonal of the main bridge are connected by a capacitor 8. The thyristor bridge is connected in series between the constant source and the load 9 In parallel to the load, a check valve 10 is connected. Adding a circuit of two series-connected thyristors leads to the formation of., -, - - two thyristor bridges (thyristors 1, 2, 3, 4, capacitor 5, thyristor ry 3, 4, 6, 7, capacitor 8). ., .- ..;

In order to use the frequency capabilities of the thyristors, it is advisable to introduce a capacitor 11 between the midpoint of the additional thyristor circuit 6, 7 and the free output of the diagonal of the alternating current of the main bridge. This leads to the fact that a third thyristor is created. and a capacitor 11.

Transformer Rabbit YELLOWDELESS .- -

The range of load current varies for two sub-bands. Each pictorial, bridge X Idensator in the diagonal works on only one subband not.

The principle of operation of thyristor bridges is identical. It is enough for the poet to understand {the principle of the operation of one of them, for example, a thyristor bridge consisting of thyristors 1, 2, 3, 4 and the Regulator 5.-

The thyristor bridge is a double thyristor key, in which two thyristor cells alternately work (1-4 or 2-3). When each pair of thyristors is pressed, the capacitor 5 is recharged by

  circuits: power source - 1-5-4-9 - source: nicpitani (YL ShorikggytTni - 3-5-2-9 - source ifs-faHHH), and into the load

 another current pulse is applied.

The thyristors are locked in a natural way at the moment of complete recharging of the capacitor 5 .-- .Maxis 1Gr of the thyristors; the range has one, IfTo e value, the frequency qn.Si -.:.-.... given current ripple value on load:,: -:; /:

The inverter control system automatically, depending on the size

J tJS: i-- - - j; s, sfci e5C5 as load, sets the operation mode of the corresponding thyristor bridge.

For example, let a greater current range correspond to the operation of a thyristor bridge consisting of thyristors 1, 2, 3, 4 and capacitor 5. When the load current decreases and the current ripple increases, the control pulses are removed from the thyristors 1, 2 and fed to the thyristors 6, 7.

Thus, a thyristor bridge comes into operation, consisting of ... resistors 3, 4 and 6, 7 and a capacitor 8. Moreover, the capacitance of the capacitor 8 is less than the capacitance of the capacitor 5.

For a given range, controlling the load current, the introduction of a capacitor 11 and, respectively, a third thyristor bridge (thyristors 1, 2 and 6, 7) makes it possible to increase the number of subranges to three. At the same time, the required frequency range for each subband is reduced:;

With a constant maximum switching frequency of the thyristors, the minimum frequencies of the subbands can be increased. This reduces the ripple of the load current and improves the utilization of the frequency capabilities of the thyristors.

The capacitance of capacitors for each subsequent sub-band is several times smaller than the capacity of the previous sub-band and much smaller than the capacitance of the most O or main pWr current range. Thyristors of sub-ranges of small-current currents can be chosen for smaller currents than thyristors of the main sub-range.

Thus, the use of additional thyristors and capacitors allows the range of current variation of the load to be expanded while maintaining a given ripple level. . ,

Claims (2)

1. DC / DC converter containing a single-phase Thyristor bridge, in the diagonal of the transient current. Which a capacitor is connected, and the DC diagonal is associated with positive input and output pins, and the output pins are reset by a return valve, differing from that, in order to expand the adjustment range and improve the shape of the output current curve, parallel to the DC diagonal of the bridge is connected, at least one additional chain formed by two thyristors, m Between the common point of the thyristors of the first additional chain and the output of the diagonal of the bridge, the first additional capacitor is connected and between the common points of the thyristors of the adjacent additional chains are also included additional capacitors. 2. The converter according to claim 1, characterized in that, in order to improve the use of frequency; thyristor capabilities, additional capacitors are connected between the common thyristor points of all non-adjacent chains, as well as between the common points and the ac leads of the bridge. Information sources, taken into account in the examination 1. Handbook of converters technique. Kiev, “Technique, 1978, p. 118, fig. 3.25. 2. Energy and information electronics. Sat Tr. MdH, Vol. 329, M., 1977, p. 15, fig. 1.3.Bulatov OG, Ivanov V.S. Adjustable thyristor current stabilizer on average and instantaneous values. - “Electrical Engineering, 1974, No. 6, p. 26