RU2311718C2 - Ac-to-dc voltage converter - Google Patents

Abstract

FIELD: converter engineering; power supplies for direct-current power consumers.

SUBSTANCE: proposed AC-to-DC voltage converter is characterized in composite parallel-and-series interconnection of rectifier arms and those of additional rectifier connected to converter output.

EFFECT: simplified design, enhanced efficiency, smoothed rectified voltage ripples.

2 cl, 3 dwg

Description

The invention relates to a conversion technique and can be used to power DC consumers, in particular for use in welding rectifiers.

Three-phase AC to DC converters are widely known, consisting of a three-phase transformer, a rectifier unit connected to the secondary windings, with a combined zero point forming a three-phase rectification circuit; a smoothing inductance is included in the rectified voltage circuit. [one].

A known converter of alternating voltage to constant, smoothing inductance in which is made of a number of windings, the number of which is equal to the number of arms of the rectifier. [2]

The disadvantages of these converters include large weight and size indicators, low efficiency, the presence of a smoothing inductance.

A three-phase DC to DC converter is also known, equipped with an additional winding covering all three core rods, a transformer and a valve, the cathode of which is connected to the transformer terminal, and the anode is connected to the midpoint of the additional winding. [3]

However, this converter is not without its drawbacks.

The technical result consists in the possibility of smoothing the rectified current and increasing the efficiency by mixed, parallel-sequential inclusion of valve arms of the rectifier.

The essence of the invention lies in the fact that in the proposed converter of three-phase AC to DC voltage, containing an AC voltage source connected to a rectifier formed by a connection of valve arms, consisting of a series-connected winding and valve of this arm, valve arms are connected in series-parallel, while the valves parallel and sequentially connected shoulders can be connected to the opposite or the same terminals of the windings (beginning or end), the valve anode been consistent arm connected to the appropriate terminals of the winding, and to free the conclusion serial circuit included an additional valve, the anode of the load; the additional valve can be switched on when the valve arms are connected in parallel by the cathode to the zero point, and the anode terminal is connected to the load.

The drawings show a schematic diagram of a device, options for including valve shoulders:

figure 1 - opposite inclusion;

figure 2 - inclusion of the same name;

figure 3 is a parallel connection.

The Converter (figure 1) contains a three-phase transformer with a secondary winding 1 (the primary winding is not shown), valve elements 2, 3, 4 with corresponding windings forming the valve arms of the rectifier, and an additional valve 5; valves 2 and 4 by combined cathodes form one converter output connected to load 6; a valve 3 connected by the cathode to a common point of the united free ends of the windings, with a winding in series and an additional valve 5, which forms the second output of the converter connected to the load 6 with the anode terminal, while the valve 3 is connected to the opposite (relative to parallel connected) end of the winding.

A winding with a valve 3 connected to the same name (similarly with parallel ones) and an additional valve 5 can also be connected in series. (figure 2)

An additional valve 5 can be connected in series, by the cathode to the zero point with a parallel connection of the three arms of the rectifier. (figure 3)

The order of connecting the valve arms can be any other, including the closing link of the serial circuit can be a link with a parallel connection of the valve arms.

The proposed Converter can be performed without an additional valve 5 (Figs. 1 and 2), the second output of the converter in this case will be a free output of a serial winding.

The positive effect when the valve arms are sequentially turned on (Figs. 1 and 2) and the additional valve 5 (Fig. 3) is to increase the efficiency, rectified voltage, smooth out ripples on the load due to pulses that occur on the valve of the serial chain arm and the additional valve.

Information sources

1. Kaganov I.L. Electronic and ionic converters, part III; M .: Gosenergoizdat, 1956

2. RU 2226738, Н02М 7/06, 2004.

3. RU 2239275, Н02M 7/06, 2003.

Claims (2)

1. An AC to DC converter comprising a three-phase transformer, the secondary windings of which together with three valves connected to the free terminals of the windings form valve arms, characterized in that the valve arms are connected in parallel-series: for example, two arms connected in parallel, connected the electrodes form the first output terminal, and the cathode of the valve of the third valve arm connected to the series is connected to the combined free terminals of the windings of these two arms But with two valve shoulders connected in parallel, the anode of the indicated valve is connected to the output of the third valve arm winding, the other output of which forms the second output terminal, while the combined terminals of the first and second valve arm windings and the output of the third valve arm winding connected to the anode of the corresponding gates, can be of the same name or opposite. 2. The Converter according to claim 1, characterized in that an additional valve is connected to the free terminal of the serial arm by the cathode, the anode terminal of which forms the second terminal of the converter.

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