SU1040535A1 - Electrical device - Google Patents

Abstract

ELECTROTECHNICAL DEVICE, containing a current-carrying part and a shell with a conductive non-magnetic section, in which holes are placed along the current-carrying part, characterized in that, in order to simplify the design while reducing losses and local heating, it is provided with electrical steel packages placed on conductive non-magnetic section from the current carrying part perpendicular to its axis between the holes and perpendicular to the holes on both sides of the current carrying part .. (L sd O1

Description

The invention relates to electrical engineering and can be applied in transformers, busbars, switchgear and other devices. Electrotechnical devices are known that contain current-carrying parts located near structural elements that, in order to reduce losses and local heating caused by an alternating current magnetic field, fully or partially are made of non-magnetic steel with large electrical resistivity. By the use of G J However, in the cases of intensive M-fields, these measures are insufficient. It is known that a further reduction in losses in a structural element of non-magnetic steel can be obtained by applying element cuts in several sections. As a result, according to the known loss dependence on the ratio of the square of the magnetic flux to the resistance of the eddy current loop, a relative increase in the resistance occurs, which leads to a decrease in the eddy current and losses. This solution is used, for example, for pressing plates and frame beams made of non-magnetic steel of the core of almost all high-power power transformers 23 However, this solution requires complicated construction and additional costs to preserve the mechanical strength of the structural element. In addition, such a solution is not acceptable for a transformer tank, as if there are cuts in the tank lid it is almost impossible to ensure reliable tightness, which is a prerequisite for oil transformers. The purpose of the invention is to simplify the design while reducing losses and local heating. The goal is achieved by the fact that an electrical device containing a current-carrying part and a shell with a conductive non-magnetic section in which holes are placed along the current-carrying part is provided with electrical steel packages placed on the conductive non-magnetic section from the current-conducting part perpendicular to its axis between openings and perpendicular 352 forming holes on both sides of the current carrying part. FIG. 1 shows a section of the device in FIG. 2 is a view along arrow A in FIG. one; in fig. 3 shows the distribution of the magnetic field in the device; in fig. 4 - eddy current contours. An electrotechnical device, for example, a transformer, contains a shell 1 (Fig. 1) with a ferromagnetic cover 2 having a portion of non-magnetic steel 3 (Fig. 1-2) with a series of holes k (Fig. 2) for the installation of inputs (inputs conventionally not shown ). The shell 1 contains the active part 5 of the device (Fig. 1) with the live parts 6 (Fig. 1-3). passing along the non-magnetic section 3 Between the holes j, the surface of the non-magnetic section 3 on the side of the current-carrying parts 6 is provided with elements of high magnetic permeability, for example, electrical steel packages 7, arranged transversely to the axis of the current-carrying parts and packages 8 located at the holes. In the absence of elements with high magnetic permeability 7 in the nonmagnetic section 3, under the action of the flux F induced by the current passing through the current-carrying part (Fig. 3), an eddy current IQ appears (Fig. C, parallel to the axis of the current-carrying part. The maximum current density takes place in the zone located under the axis of the current carrying part.In the shell, equipped with elements of high magnetic permeability, for example, electrical steel 7 packages, the distribution of the magnetic field (Fig. 3) is such that the zones are non-magnetic The first section of the envelope located between the packages penetrates the flow of one direction p, and the areas under the packages - the magnetic flux Fr of the opposite direction.In this case, separate contours of eddy currents of different directions i and i / appear in the areas between the packages and under the packages (Fig.) Thus, the common contour of the eddy current is divided into several contours, or the path of the eddy current is significantly longer.

which, as in the case of mechanical cuts, leads to a decrease in eddy currents and, consequently, losses and local heating.

The proposed electrical device eliminates cuts in the shell and thus does not require special structural measures to ensure the tightness and mechanical strength of the shell, which are necessary in the case of cuts, and can also be applied to structural elements made of other non-magnetic electrically conductive materials. less depth of penetration of the floor into the conductive medium of the remote control.

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Claims (1)

An ELECTROTECHNICAL DEVICE containing a current-carrying part non-magnetic section from the current-carrying part perpendicular to its axis between the holes and perpendicular to the forming holes from two sides of the current-carrying part. PhagZ in switchgear