RU1815681C - Transformer for rectifier power supply - Google Patents

Abstract

Usage: in electrical engineering. Essence: Transformer 1 contains a magnetic wire 2 with symmetrical main 3 and side 4 frames. On the rod x 5 of the magneto-wire, there is a network winding 6, connected by a star circuit and two parts 7 and 8 of a valve winding, respectively connected by a direct star circuit and a reverse star with a common zero point 9. The valve winding is connected to rectifier 10. 1 silt.

Description

The invention relates to electrical engineering, in particular to converter power transformers.

The aim of the invention is to expand the scope and improve the technical and economic performance of the transformer.

The drawing shows a diagram of a transformer for powering a rectifier.

Transformer 1 contains a magnetic wire 2 with symmetrical main 3 and side 4 frames. On the rod x 5 of the magnetic circuit there is a network winding 6 connected in a star pattern, and two parts 7 and 8 of a valve winding connected respectively in a straight star pattern and a reverse star with a common zero point 9. The valve winding is connected to rectifier 10.

The transformer operates as follows.

When the transformer 1 is connected to the mains supply, the voltages of parts 7 and 8 of the valve winding, due to the common zero point 9, form a six-phase voltage system. The presence of side belts 4 provides rectifier 10 for the operating mode to easily close them, along with magnetic main frequency flows, as well as triple frequency streams (and non-multiple ones) generated by rectifier 10 and coinciding in phase in the terminals 5 of the magnetic core of transformer 1. As a result of voltage of parts 7 and 8 of the valve coil, at the fundamental frequency, they contain three higher harmonic frequencies, which are non-multiple three, which even out the instantaneous voltage values of the adjacent phases of the six-phase voltage system. For the entire operating range of rectifier 10, this provides simultaneous pairwise conductivity of two rectifier gates 10 and two phases of the valve coil, respectively belonging to parts 7 and 8, with a conduction duration of each valve (of each phase of the valve coil) of 120 degrees. , despite the absence in the circuit of a two-phase surge reactor.

The triple-frequency flows superimposed on the main-frequency flows determine not only the conductivity mode of the valves and phases of the valve winding of the transformer, but also the value of the equalizing current of rectifier 10, the amplitude values of the fluxes of rods and rods, as well as the loss and heating of sections of the magnetic circuit and structural elements of the transformer . In this case, the magnitude and phase of the triple frequency magnetic flux substantially depends on the angles of control of the valves (on the depth of regulation of the rectifier voltage) and the geometry of the magnetic circuit and the entire design of the

transformer. In particular, an increase in the amplitudes of magnetic fluxes necessitates an increase in the cross-section of the transformer rods and a change in the cross-sections of its rem relative to the standard construction of a transformer operating by sinusoidal induction and calculated according to well-known formulas. The required increase in the cross sections of the rods is taken into account in the claims by the coefficient

5 1.09-1.14, and changes in the cross-sections of the rem - the corresponding ratio (0.58-0.75). The specific values of the cross sections that determine the geometry of the magnetic circuit depend on the depth of the voltage control, the switching reactance, and the standardized dimensions of the structural elements.

Smaller values of the coefficients relate to transformers with a small depth of regulation of voltage, large 5 to a greater depth of regulation.

To calculate the geometry of the magnetic circuit of the transformer of the controlled converter with a voltage control depth of 100%, we accept for the cross section of the rods

0 magnetic core, the coefficient before the shot is 1.14, and the cross-section is 0.75 of the cross-section of the rods.

When determining the cross-section of the rods of the magnetic circuit of the transformer of an uncontrolled converter (regulation depth 0%), we take the coefficient equal to 1.09, and the cross-section of the rem - 0.58 of the cross-section of the rods.

The intermediate values of the coefficients relate to the intermediate values of the magnitude of the voltage regulation depth.

The magnetic circuit calculated in accordance with the foregoing will provide the permissible overheating and the permissible equalizing current. The use of the invention in relation to transformers with an integrated reactor, for example, for furnace plants, i.e. performing them on a reactor

0 scheme, will allow to improve their technical and economic performance by about 20% by reducing the consumption of materials, losses, reducing the size.

Claims (1)

The claims 5 A transformer for powering the rectifier, containing a three-core magnetic circuit with two symmetrical side frames: on the rods of which are connected to the star network winding and two parts of the valve winding with circuits connections are direct star and reverse where l / l is a linear sinusoidal voltage star with a common zero point, the power supply network is: and with the fact that, in order to expand Wco, the number of turns of the network winding; areas of application and improvement of the technique-Sun - permissible amplitude value economic indicators, rod-5 section of sinusoidal induction; it is selected by the formula f is the voltage frequency; s / 1 to 1 sh la main and side frames, made with bc (T.iu i. ™ j 444 Wco f Sun Vs with sections of 0.58-0.75 from the section of the rods.