SU1767662A1 - Alternating-to-direct current transformer - Google Patents

Abstract

Usage: the invention can be used in reactive power sources, direct current electric drives, alternating current electric locomotives. SUMMARY OF THE INVENTION: The AC-DC converter contains a transformer, the ends of the secondary winding 25 of which are connected to the AC power supply terminals of the rectifier (CB) at the valves 1-6 and the terminals of the transient current of the auxiliary rectifier (ЈВ) to the veins

Description

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til x 9-14, made on a three-phase bridge circuit. The DC outputs of an explosive are connected to a capacitive filter on capacitors 23,24. At least one group of valves CB is made controllable. Each DC output CB, formed by power electrodes of controlled valves, is connected to the same output TTbstr of other explosive currents through controlled Ient 7 (8), shunted by a chain of serially connected fully controlled valve 15 (16) and switching capacitor 17 (18), to the conclusions of which is connected source 19 (20) podzar yes. The remaining DC output current CB is connected directly to the same output DC current explosive. DC terminals are connected directly to the terminals.

The invention relates to converter equipment and can be used in reactive power sources, direct current electric drives, alternating current electric locomotives.

The known AC-to-DC converter containing a transformer, the secondary winding of which is connected to a rectifier bridge on two diodes and two controlled valves, two diodes connected to the terminals of the secondary winding of the same electrodes with thyristors, a capacitor connected to the terminals of a constant of the current of the diode bridge, and the switching node of a series-connected fully controlled valve and a switching capacitor shunted by a source of charging current (ed. St. N 1171933, class H 02 M 7/15 five).

Closest to the proposed AC-DC converter (ed. St. 1246290, cl. H 02 M 7/155), which contains a transformer, the secondary winding of which is connected in a star and connected to a power bridge on controlled vents to the bridge. The DC outputs of the diode bridge are connected to a capacitive filter in the form of two series-connected capacitors, and through fully controlled valves and switching capacitors, bypassing the load. In the three-phase converter, the secondary winding of the transformer is three-phase and connected to a star. Capacitors 23,24 are connected in series and their common point is connected to the common point of the indicated star. The DC terminals CB are connected via additionally introduced diodes 21, 22 with opposite DC terminals of the explosive. The above implementation of the device makes it possible to reduce the capacity of the switching capacitors, the power of the sources of charging, improve the weight and dimensions, and reduce the cost. Reducing the current load of fully controllable gates improves the reliability of the converter. 1 hp ff, 2 ill.

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Baths with a source of charging are with the same-name DC terminals of a power bridge. The common point of the filter capacitors is connected to the star's neutral. The DC terminals of the power bridge are connected via diodes to the opposite DC terminals of the diode bridge.

The lack of a converter is reduced technical and economic indicators, which are caused by increased current load of fully controlled valves, increased power of sources of charging, degraded weight and dimensions, and increased cost.

The purpose of the invention is to improve the technical and economic performance of the converter.

The goal is achieved by the fact that, in contrast to the known AC-DC converter, containing a transformer, the ends of the secondary winding of which are connected to the AC terminals of the power rectifier and AC terminals of the auxiliary rectifier, made according to a bridge circuit, DC outputs Auxiliary rectifier connected to a capacitive filter. At least one group of power rectifier valves is controllable. Every conclusion

direct current power rectifier, formed by power electrodes controlled valves, connected to the same output DC auxiliary rectifier through serially connected fully controlled valve and switching capacitor, shunted by a power source, the remaining output DC power rectifier directly connected with the same DC output of the auxiliary rectifier. The DC terminals of the power supply rectifier are connected directly to the terminals for connecting the load. In the proposed converter, each of the series connected indicated fully controlled valve and the switching capacitor are shunted by an additionally introduced controlled valve. The secondary winding of the transformer is made three-phase and connected in a star. The capacitive filter is made of two series-connected capacitors, the common point of which is connected to the common point of the specified star. The power and auxiliary rectifiers are three-phase. The DC outputs of the power rectifier are connected via additionally introduced diodes with opposite terminals of the DC auxiliary rectifier.

Through the fully controlled valves and switching capacitors, the current passes during the circuit time, which allows reducing the capacity of switching capacitors, power of charge sources, improving weight and dimensions, and reducing cost. Reducing the current load of fully controllable gates improves the reliability of the converter.

Figure 1 shows a schematic diagram of an AC-DC converter, figure 2 shows a schematic diagram of a single-phase AC-DC converter, which can be used on AC electric locomotives.

The AC-DC converter contains a power rectifier on controllable gates 1-6, connected via control valves 7.8 to an auxiliary rectifier on gates 9-14. Parallel controlled valves 7.8 include connected in series fully controlled valves 15–16 and switching capacitors 17–18, shunted by sources

19.20 sunbathe yes. The DC outputs of the power rectifier through diodes 21, 22 are connected to the opposite DC terminals of the auxiliary rectifier, to which capacitors 23, 24 connected in series are connected, the common point of which is connected to the neutral of the secondary winding of the transformer 25. The winding leads 25 are connected with conclusions

0 AC power and auxiliary rectifiers. The smoothing reactor 26 is connected in series with the load 27. The polarity of the voltage on the capacitors is indicated in the drawing.

5In the case when controlled

valves 1 and 2, the load current 27 passes through the circuit: 27-2 - phases C and A of the winding 25-1-26- 27. To turn off the controlled valve 1 and unlock the controlled valve 8. The capacitor 24 is open above the amplitude value the voltage of the phase of the secondary winding 25 and is applied to the phase A of the secondary winding. In this case, the load current 27 passes through the circuit: 27-2 - phases C and A of the winding

5 25-1-26-27, as well as along the circuit: 27-2 - phase C of the winding 25-24-8-26-27. The phase A current of the winding 25 decreases. When the phase A current of the winding decreases to zero or when the capacitor 24 is discharged, the fully controlled valve 16 and the controlled valve 9 are discharged to the specified value. The voltage of the switching capacitor 18 is applied to the valves 1.8, and they turn off. At the end of the circuit time off

5, a fully controlled valve 16 and unlocking the next entering into operation controlled valve 3. A load current 27 passes through the circuit: 27-2 - phase C of the winding 25-23-21-26-27. By phase B of winding 25, the voltage of capacitor 23 is applied, and the current in the winding begins to increase. There is a charge of the capacitor 23. At the end of the transition process, the current passes through the circuit: 27-2 - phases C and B windings 25-3-26-27.

5 To turn off the controlled valve 2, unlock the controlled valve 7. The voltage of the capacitor 23 is applied to the phase C of the winding 25, and the process proceeds as described above.

Claims (1)

1. AC-DC converter containing a transformer, the ends of the secondary winding of which are connected to the AC power terminals 5 rectifier to AC outputs of the auxiliary rectifier, made according to the bridge circuit, the DC outputs of the auxiliary rectifier are connected to the capacitive filter, at least one group of the fan rectifier is made controllable, each DC output of the power rectifier formed by the power electrodes of controlled valves connected to the same DC output of the auxiliary rectifier through a fully connected fully controlled valve and switch in series the capacitor shunted by the charge source, the remaining DC output of the power rectifier is connected directly to the DC output of the auxiliary rectifier of the same name, the DC terminals of the power rectifier are connected directly to the terminals for connecting the load, characterized in that technical and economic improvements indicators, each of a series of said fully controlled valve and switching capacitor connected in series is shunted by an additionally introduced control valve. 2, the converter according to claim 1, wherein the transformer secondary winding is three-phase and connected in a star, the capacitive filter is made Of the two series-connected capacitors, the common point of which is connected to the common point of the indicated star, the power and auxiliary rectifiers are three-phase, the DC outputs of the power rectifier are connected through additionally introduced diodes with different DC terminals of the auxiliary rectifier. ftJ. t-Tribf & t G7GP QLJ /. 2