SU523496A1 - Three-phase AC to DC converter - Google Patents

Description

one

The invention relates to the field of converter technology and can be used to convert a three-phase alternating voltage into a constant with a low level of ripple during regulation.

Twelve-pulse controlled rectifiers are widely known. They are made on a transformer with two secondary windings connected in two stars and containing 12 thyristors as the minumum 1.

The prototype of the invention is a three-phase alternating voltage-to-constant voltage converter containing a rectifier and a three-phase transformer with two secondary windings connected in 2 stars, zero points of which form the output terminals 2.

The aim of the invention is to simplify the converter.

This goal is achieved by the fact that the valves form two anodic and two cathodic groups, one of each pair of these groups is controllable, and each secondary phase winding has a tap, and the leads of the first winding are connected to the leads of the second winding uncontrolled gates, and taps of the second winding are connected to pins first through the anode group of controlled and cathode group of uncontrolled gates.

Pa figs. 1 shows a schematic diagram of the proposed rectifier; pas figs. 2 is a vector diagram of phase and rectifiable voltages.

The 12-pulse controlled rectifier consists of a power transformer 1 with two identical secondary windings 2 and 3, each connected in a star, between the zero points of which the load 4 is turned on.

Conclusions 02, 2, 2 of the secondary winding 2 through the cathode group of valves 5, b, 7 n the anode group of thyristors 8, 9, 10 are connected to the taps uj, bi, to the I secondary winding 3, and taps Ofi, b from the secondary winding 2 through the cathode group of thyristors 11, 12, 13 and the anode group of valves 14, 15, 16 are connected to terminals 02, 22, and C2 of the secondary winding 3 of transformer 1.

The 12-pulse rectified voltage at load 4 is formed by rectified voltages (see Fig. 2) and; and. -and S and.; U -, U; U

a, bia, CiaiC2 fz - l

and; ; /; and about ,

Ci02 CMj c., Oi c, 0-2 Ui0r

whose value is determined by the formula:

.- / (1T 1 In this case, the valves operate every 30 e hail, in the following sequence: 5–9; 5–10; 11–16; 12–16; 6–10; 6–8; 1215; 13–14; 7-8; 7-9; 13-15; 11-15.

To obtain a symmetric 12-pulse straightening, it is necessary to select and, 1 / 3-1 and 2

Each of the thyristors at 8-13 is opened by control pulses twice with an interval of 90 electr. hail, for a period of variable supply voltage. The pulses controlling the thyristors 11, 12, 13 are synchronized with the positive half-waves of the respective phase voltages, and the pulses controlling the thyristors 8, 9, 10 are synchronized with the negative half-waves of the corresponding phase voltages.

Claims (1)

Claims of the Invention A three-phase alternating voltage converter into a constant voltage comprising valves and a three-phase transformer with two secondary windings connected in two stars, zero points of which form output terminals characterized in that for the sake of simplicity, the valves form two anode and two cathode groups, one of each pair of these groups is controllable and each secondary phase winding has a tap, and the leads of the first winding are connected to the terminals of the second winding through the cathode group of controlled valves, and the taps of the second winding are connected to the terminals of the first through the anode group of controlled and cathode a group of uncontrolled gates. Sources of information taken into account in the examination: 1 A.M. Bandas et al., “Static Electromagnetic Frequency and Phase Converters, Gosenergoizdat, 1961. 2 Avt. St. No. 265254, 1970. and. Uo