SU974439A1 - Earthing device - Google Patents

Description

(54) GROUNDER

The invention relates to high-voltage instrumentation, in particular, to earthing devices that are operable in icy conditions, and can also be used in short circuits, separators and disconnectors.

The known instance contains a fixed contact mounted on high-voltage equipment, and a movable grounding knife of the cutting type with a lamella contact at the end, and the fixed contact is made in the form of a plate into which a lamella contact is cut in when switched on. From icy motion fixed contact for-. covered by a casing. Slats are installed with a clearance relative to each other flj.

A disadvantage of such a grounding conductor is that ice may form in the lamella contact, the ice crust of which covers the contact surfaces of the lamellae and the gap between them. In order to provide the necessary electrical contact between the lamellae and the fixed contact, when the grounding knife is turned on, it is necessary to peel a layer of ice from the lamellae. When the knife is turned on, a layer of ice undergoes cutting control and for

its destruction requires great efforts, since the ice has a considerable shear strength when cut, and its surface on the lamellae is large.

In addition, for cleaving the ice, the impact energy of the grounding knife on the fixed contact is used, which requires an increase in the mechanical strength of the grounding elements and

10 of the drive and high voltage equipment on which the contact is made.

The closest technical injury to the invention is the land surveyor, which contains a fixed contact installed on high-voltage equipment, and a grounding knife of cutting type with lamellae at the end, installed with a gap relative to each other f2j.

Ice may form on the ground of this earthing, as there is a gap between them and they are not protected by anything.

25

Ice destruction at these earthing is also carried out due to the impact energy of the included grounding knife and occurs after the specific pressure on the ice in 30 lamellas exceeds the shear stress.

This requires an increase in the mechanical strength of the earthing elements and reduces the reliability when operating. In ice conditions, since a shock load acts on these elements when switched on.

The purpose of the invention is to increase the reliability of operation during icing by reducing shock loads on the insulation of high-voltage equipment when switching on the earticle.

In order to achieve a target earthing switch containing a fixed contact installed on a high-voltage equipment and a grounding knife of a cutting type with lamellas at the ends installed with a gap relative to each other, the knife is provided with an elastic casing closing the gap between the lamellae in the disconnected state and made the possibility of deflection in the specified gap when turning on the grounding.

Moreover, the casing can be made in the form of a thin-walled plate of elastic material, in the form of several rods of elastic material arranged in a row, in the form of plates hinged on elastic rods, in the form of a plate of elastic material located on elastic rods.

FIG. 1 shows the proposed earthing switch, including a posited, general view; in fig. 2 shows the end of the grounding blade with lamellas, the disconnected position; in FIG. 3 section aa on. 2, lamella contact with the casing in the form of a thin-walled plate of elastic material / in FIG. 4 - the same, with a casing in the form of rods of elastic material arranged in a row, in FIG. 5 is a view B in FIG. 2 when performing the casing according to FIG. four; in fig. b - the same as in FIG. 3, with a casing in the form of plates hinged on rods of elastic material / in FIG. 7 is a view B in FIG. 2 when performing the casing according to FIG. l; on Fx, 8 - the same as in FIG. 3, with a casing in the form of a plate of elastic material disposed on rods of elastic material; in FIG. 9, view B in FIG. 2 when performing the casing according to FIG. eight.

The earthing switch consists of a ground cable of the knife 1, a fixed contact fixed at the top of high-voltage equipment 3. At the end of the knife 1 are slats 4 with a gap of 5 between them. The tip of the knife 1 is fixed to the casing 6, closing the gap 5. When the ice is covered, a crust of ice covers the outer surfaces of the lamellae 4 and the casing b. The gap 5 between the lamellae 4 and the contact (internal) surfaces on them is not ice. are covered so

as this prevents the casing 6. When the earthing knife 1 is inserted into the fixed contact 2, the cantilever part of the casing b abuts against the contact 2 and bends elastically into the gap 5 between the laps 4, as a result of which the ice on the casing b is easily destroyed because the ice crust does not cleave, but breaks over the entire bend of the casing b. It is known that the ultimate strength of ice as a brittle material when bent is much less than the ultimate strength at cutting. The electrical contact of the included grounding knife 1 occurs between the ice-free internal (contact) surfaces of the lamellae 4 and the fixed contact 2. When the knife 1 is disconnected, the casing b returns to its original position by internal elastic forces and closes the gap 5 between the lamellae 4.

FIG. 3 shows a casing, made in the form of a thin-walled plate of elastic material, for example, of spring steel.

FIG. 4 and 5, a casing is shown made in the form of rods 7 arranged in a row of elastic material, for example, spring steel of circular, rectangular or other section. When the rods are turned on, bending in different directions, as a result, the ice crust on them is easily destroyed. FIG. 6 and 7 show a casing made in the form of a set of plates 8 pivotally arranged on rods

7 of an elastic material, for example spring steel. This casing looks like a bracelet. When turned on, the rods 7 bend at the points of contact.

plates 8 with each other, and the ice breaks here.

FIG. 8 and 9 show a casing made in the form of a plate 9 of an elastic material, for example rubber,

rubberized fabric, plastics, etc., attached to the rods x 7 of elastic material (spring steel). When turned on the plate

8 on the rod x 7 sags in all sections, resulting in a crust

ice is easily overlaid.

The elements of these casings can be made of a material with low adhesion (adhesion) with respect to ice, for example, fluoroplastic, or covered with a thin layer of such material. In this case, the casing can be installed not only on the top of the lzmel, but also additionally on the other side (bottom), providing

protection of the contact surfaces at the location of the knife in intermediate positions (close to vertical) The casing can also be used in the case of the arrangement of lamellas

not on the grounding knife, but at the top

high-voltage equipment. The design of such an anti-icing casing is simple and practically does not increase the torque on the shaft of the grounding shaft.

The implementation of the proposed invention allows to significantly improve the performance of the earticle in icy conditions without increasing the strength of the earthing elements and drive power, as well as reduce the impact loads on the insulation, increase reliability and make the design simple.

Claims (5)

1. A grounding device containing a fixed contact mounted on high-voltage equipment and an earthing ground cutting knife with lamellae at the end installed with a gap relative to each other, distinguished by the fact that, in order to increase the reliability of operation during icing by reducing shock loads on isolation of high-voltage equipment when the earthing switch is turned on, the knife is provided with an elastic casing closing the gap between the lamellae in the disconnected state and configured to bend into the specified gap when the ground is turned on Itel. 2. Grounding device pop. 1, characterized in that the casing is made in the form of a thin-walled plate of elastic material. 3. The earthing device according to claim 1, characterized in that the casing is made completely in the form of several points, which are southern in a row of rods of elastic material. 4. The earthing device according to claim 1, wherein the casing is made in the form of plates mounted hingedly on elastic rods. 5. A grounding device according to claim 1, characterized in that the casing is made in the form of a plate of elastic material disposed on elastic rods. Sources of information taken into account in the examination 1.Afanasyev V.V. and Yakunin E.N. 5 Disconnectors. L., Energie,. 1979 ,, with. 27, fig. 1-13. 2. Instructions for use. NSA disconnector grounding knives. Model B from ASEA. Battery 1975-06-23, p. five. . h