RU231654U1 - Fixed contact of high-current disconnector - Google Patents

Abstract

The utility model relates to electrical engineering, in particular to the designs of high-precision disconnectors that can switch currents of up to 300 kA and higher in energy-intensive electrochemical processes, such as electroplating, electrolysis, arc and induction furnaces. The technical result is achieved by using a fixed contact and consists in increasing the reliability of the disconnector. The fixed contact of the high-current disconnector contains a rectangular busbar 1 made, for example, of aluminum, to the end surface of which, using studs 2 with disk springs 3 and nuts 4, a connecting plate 5 is attached, made of copper with a contact surface 6 made of a silver-nickel alloy. In the connecting plate 5, there are slots 8, which are limited on both sides by a solid part of the connecting plate 5. 3 fig.

Description

The utility model relates to electrical engineering, in particular to the design of high-precision disconnectors that can switch currents of up to 300 kA and higher in energy-intensive electrochemical processes, such as electroplating, electrolysis, arc and induction furnaces.

Based on the experience of operating existing high-current disconnectors, the following causes of deterioration (burning) of contacts have been identified:

difficult operating conditions (dirt, dust, precipitation, etc.);

inadequate maintenance;

skew of moving contacts.

This leads to:

deterioration of the contact at the junction of the moving contact and the fixed contact (or several moving contacts) of the DC disconnector pole;

reducing the current through it (them) and, consequently, increasing the current through other contacts that are not designed for such a current.

Undamaged contacts begin to overheat, the contact surface loses its properties and conductivity, which leads to even greater deterioration of the contacts and can lead to the destruction of the disconnector.

A fixed contact of the high-current disconnector HCD 120 from RITTER Starkstromtechnik GmbH is known, which includes a rectangular aluminum busbar with a silver contact surface (https://www.ritter-starkstromtechnik.de/ru/en/Leistung/Schaltanlagen-%D0%B8-Schaltgeraete/Schaltgeraete/Schaltgeraete-Fuer-Hochstromtechnik/%D0%96%D0%9A%D0%94.php, found on the Internet on 14.09.2024, see Appendix to the application).

The closest technical solution in terms of the general set of features, selected by the applicant as a prototype, is a fixed contact of a high-current disconnector containing a rectangular busbar, to the upper end surface of which, by means of rows of studs with spring washers, square copper connecting plates are attached, a row of which along the length of the busbar overlaps the end surface of the busbar, wherein each plate has a slot along the vertical axis with the slot exiting onto the side of the plate, and the contact surface of each plate is made of silver or a silver-based alloy (US 2023/0368987 A1).

The disconnector is capable of deformation up to ±30 mm in any plane. This is known from the practice of disconnector operation, and is also described in US 2023/0368987 A1. During deformation shift of the movable blades of the disconnector taken as a prototype, the contacts on the blades can fall into the gaps between the square copper connecting plates. In addition, when installing square copper connecting plates, it is quite difficult to maintain the tolerance of the displacement of one plate relative to the adjacent one, which leads to the formation of a stepped contact surface and, accordingly, gaps between the contact surface of the fixed contact and the contacts of the movable blades, which in turn causes uneven current flow and heating of the contact surfaces.

The technical task of the claimed utility model is to increase the reliability of the operation of the contact surfaces of the disconnector.

The technical task is achieved in that the fixed contact of the high-current disconnector contains a rectangular busbar, to the upper end surface of which a copper connecting plate is attached by means of rows of studs with disk springs, provided with a contact surface made of a silver-based alloy, wherein the copper connecting plate has a slot along the vertical axis between the rows of studs, characterized in that the copper connecting plate is solid, is made in the form of an elongated rectangle and is installed on the entire area of the end surface of the rectangular busbar, has additional vertical slots, limited on both sides by a solid part of the plate.

A comparison of the claimed utility model with the prototype shows that it has the following features:

The copper connecting plate is solid;

the copper connecting plate is made in the form of an elongated rectangle;

the copper connecting plate is installed over the entire area of the end surface of the rectangular busbar;

the copper connecting plate has additional vertical slots;

additional vertical slots are limited on both sides by the solid part of the plate.

Therefore, it can be assumed that the claimed utility model meets the “novelty” criterion.

The utility model can be manufactured on known equipment, therefore it meets the criterion of “industrial applicability”.

Fig. 1 shows the claimed utility model installed in a disconnector of the RPT-35-M-Al/AL brand;

Fig. 2 shows the connecting plate;

Fig. 3 shows a top view of the connecting plate.

The device comprises a rectangular busbar 1 made, for example, of aluminum, to the end surface of which a connecting plate 5 is attached by means of studs 2 with disk springs 3 and nuts 4, made of copper (designated as Cu in Fig. 2) with a contact surface 6 made of a silver-nickel alloy (designated as Ag in Fig. 2), with a nickel content of about 10 wt.%. Making the contact surface 6 from a silver-nickel alloy ensures the necessary hardness of the contact surface. In the connecting plate 5 there are slots 8 (Fig. 2, 3), which are limited on both sides by a solid part of the connecting plate 5. The slots 8 ensure an increase in the tightness of the fit of the connecting plate 5 to the busbar 1 when tightening the nuts 4.

In Fig. 1, pos. 7 indicates the movable contact of the disconnector.

If the contact surface 6 is worn out or damaged at the fixed contact, the connecting plate 5 of the fixed contact is replaced in the following sequence:

1. Unscrew all nuts 4 from studs 2 and remove disc springs 3;

2. Remove the connecting plate 5 of the fixed contact;

3. A new connecting plate 5 of the fixed contact is installed;

4. Install disc springs 3 and nuts 4;

5. By tightening the nuts 4 and the disc springs 3, the necessary pressure of the connecting plate of the fixed contact to the disconnector bus is ensured.

The peculiarity of the claimed design is that when the disconnector contacts are closed, the contact surfaces of the moving contact lie on the solid contact surface of the fixed contact. Tests of a high-current disconnector with the claimed fixed contact have shown that small transverse deviations of the moving contact blades do not cause uneven current flow and overheating of the contacts.

Thus, the claimed design ensures reliable operation of the disconnector and maintains high maintainability.

Claims (2)

1. A fixed contact of a high-current disconnector, comprising a rectangular busbar, to the upper end surface of which a copper connecting plate is attached by means of rows of studs with disk springs, provided with a contact surface made of a silver-based alloy, wherein the copper connecting plate has a slot along the vertical axis between the rows of studs, characterized in that the copper connecting plate is solid, is made in the form of an elongated rectangle and is installed over the entire area of the end surface of the rectangular busbar, has additional vertical slots, limited on both sides by a solid part of the plate. 2. A fixed contact of a high-current disconnector according to claim 1, characterized in that the silver-based alloy contains nickel of about 10 wt.%.