SU765894A1 - Transformer - Google Patents

Description

one

The invention relates to transformers, in particular to powerful high-voltage and ultra-high-voltage transformers.

Transformers are known in which electrostatic screens mounted on the magnetic cores under the first windings and not connected to the winding 1 are used to increase the electrical strength of the main oil-barrier insulation, and not connected to the winding 1. It can also build ground potential, the value of which determined by the capacitive coupling of the oGMOiOK, the magnetic circuit and the screen.

With this design of the transformer, the capacitive distribution of voltage is improved, the screen partially ennobles the field, but does not ennoble the electric field at the end of the winding with a linear output, since the screen does not fit the frontal part of the windings.

Also known is a transformer containing a magnetic core on the terminals of which windings are installed with capacitive rings placed at the line terminal on the edge of the winding.

Winding insulation in the form of cylinders and angle washers and electrostatic screens, enclosing cylindrical surfaces and ends of the winding and galvanically connected to it 2. The potential of the capacitive ring is communicated to the screen. It improves the surface of the winding, whereby the insulating gap of buTO oil-oil insulation is chosen for lighter conditions.

The disadvantages of this design of transformers include the fact that the electrostatic screen

I c is used only for layer type windings. The screen does not subdivide the insulating gap and does not regulate the intensity of the electric field in it, but only delimits the surface that it encloses (in this case, the inner surface of the winding and eivixocT ring), which limits the ability to reduce insulation

25 span.

Claims (1)

The aim of the invention is to reduce material consumption by reducing inter-amp insulating insulation distances by turning the electrical insulation strength. To this end, in the famous trance. the formatter containing the magnetic core on the rods of which are installed windings with capacitive rings placed at the line terminal on the edge of the winding are winding insulation in the form of cylinders and corner washers and electrostatic shields, surrounding cylindrical surfaces and windings and galvanically connected to it, the screens are located: at intervals equal to 3-10% of the size of the inter-winding insulation, and the first screen from the winding is removed from the winding and capacitive ring at the same distance and is galvanically connected to one of the sections of the input zone, and the subsequent screens are galvanically connected to the winding sections in the subsequent winding zones, the electrostatic screen can be made as a hollow toroid covering a part of the winding. FIG. Figure 1 shows the phase of a transformer with several electrostatic screens; in fig. 2 phase transformer with one toroid electrostatic screen. A powerful high-voltage power transformer (see Fig. 1) contains a magnetic core 1, windings 2 placed on the cores of the magnetic circuit 1 and equipped with capacitive rings 3 mounted on the ends of the winding at the line terminal 4, oil barrier 1 insulation 5 and electrostatic screens 6 installed on the windings of higher voltage. The insulating gap l between the windings, for example, the lowest and highest voltages (or between the magnetic core and the first winding from the core) is divided by an electrostatic screen into a number of gaps. The first screen b is installed at a distance from the winding and the capacitive ring, corresponding to 3-10% of the insulation size between the windings. The distance between the successive screens is also equal to 3-10% of the size of the interwire insulation. Screens 6 are galvanically coupled. with winding, for example, at the point of transition from section, c. section. The first screen 6 is galvanically connected to the winding in the input zone remote from the line output for 5–15 sections, which provides it with potential from the potential of the capacitive ring. Subsequent screens are galvanically connected to the winding in subsequent zones in 5-15 sections. X1 each screen 6 reports its potential, decreasing in magnitude from the first. For example, when line terminal 4 is located at the end (at the edge of the winding (and not in the gray of one)) capacitive ring 3 connected to the latter has a potential equal to 100% of the potential of the linear output (for all types of effects). equal to 100% - d and 90-85%, to the second 100% - AUa 70-65%, etc. And, u ,, j, and 2 7, etc. The potential value and screen connection for each type of transformer Each gap between the screens 6 is affected by the potential difference, set by the winding, the magnitude of which depends on the class of insulation of the winding and of the insulation materials, the gap. The edge of the winding (see Fig. 2) in some cases, for example, when the end (edge) of the winding is of great importance for test voltages, it is advisable to carry out the electrostatic screen b first from the winding in the form of a hollow toroid, which also, as described above, galva It is physically connected to the winding in an area remote from the linear output of 5–15 sections and has a potential equal to (100% -di), i.e. has the same potential as the first screen in FIG. 1. The studies performed showed that installing electrostatic screens made according to the invention allows to equalize the electric field in the gap between the capacitive ring and the screen by telling the screen of a given potential value, which reduces the electrical intensity in this gap and, consequently, reduces its size . Since the radius of curvature of the screen is larger than the radius of the capacitive ring, the period of low voltage winding - medium voltage (or other) winding, as well as the period of the pressing ring (or core) - the electrostatic screen can be reduced. Reducing the voltage of the above-mentioned insulation gaps increases the reliability of transformers, and reducing the size of the interwinding insulation gaps reduces copper consumption by 5%, electrical steel by 3%, and this, in turn, reduces the loss of holos-. that turn and short circuit on 5%. Claim 1. Transformer containing magnetic core, on rods of which