RU201052U1 - High voltage electromagnetic contactor - Google Patents

Abstract

The utility model relates to the structural elements of electrical switches, namely to devices for extinguishing the arc between current-carrying elements, and can be used to disconnect electrical circuits. The technical result is to increase the efficiency of arc suppression and increase reliability by reducing heat generation in the process of arcing, which, in its turn, it affects the wear resistance of the contactor parts and, as a consequence, the reliability of the contactor operation. High-voltage electromagnetic contactor, operating on direct current, assembled in a housing and containing two contact parts with fixed and one contact part with moving contacts, two permanent magnets, placed near each of the stationary contact-parts and designed to create a constant magnetic arc suppression field, and two coils placed near each of the stationary contact-parts and designed to create an electromagnetic arc suppression field for drawing in and extinguishing arcs arising when and contact details, arc chutes serve. The movable contacts of the contact parts are located on the contact bridge, the permanent magnets belonging to the two contact parts are polarized in opposite directions, a guide for the arc is placed near each contact part, isolated from the fixed contacts, and the corresponding coil is electrically connected to the corresponding fixed contact and corresponding guide for the arc, characterized in that it is equipped with two dividing elements located vertically in the interval between the guides and between the chambers and made in the form of ceramic plates. 2 ill.

Description

The utility model relates to the structural elements of electrical switches, namely to devices for extinguishing the arc between current-carrying elements, and can be used to disconnect electrical circuits.

Various methods are known for extinguishing the arc, depending on the field of application: a contactor operating on direct current of a constant direction usually has permanent magnetic arc suppression fields, which are placed so that the magnetic field is directed perpendicular to the arc. The arc suppression fields act on the arc by the Lorentz force, with which the arc moves in the direction of the arc extinguishing chamber.

When working on a bi-directional direct current, for example, in the case of a return of electricity to the network during tram traffic or in in-circuit emulators, when using several alternately active pantographs, as well as when working on alternating current, constant magnetic fields cannot be used, since the direction of the current in the arcs changes. In this regard, in such cases, so-called arc-extinguishing coils are usually used, which create an electromagnetic arc-suppression field, the direction of which is determined by the direction of the current. As a result, a correctly oriented force acts on the arc in each case, regardless of the direction of the current.

However, the use of coils has several disadvantages. As a result of the constant flow of high currents through the coil, as is usually the case in rail transport, strong heating occurs. Therefore, they try to delay the excitation of the coil until it is turned off. However, the coil creates an electromagnetic arc suppression field with a time lag (exponential dependence), as a result of which the arc time in the contact zone of the contactor is further increased.

On the other hand, at low currents, the coil creates a weak arc suppression field. As a result, it may turn out that this arc suppression field will not be enough to pull the arc into the arc chute and extinguish the arc (critical current range).

A contactor is known in which a permanent magnet is used together with an inductor to create an arcing field [1].

The known high-voltage electromagnetic contactor contains a contact - parts with fixed contacts and moving contacts. Near each of the contact - parts, there are two permanent magnets to create a constant magnetic arc suppression field, and two coils to create an electromagnetic arc suppression field. An arc extinguishing chamber serves to draw in and extinguish the arcs arising when the contact - parts are opened. Near each contact - part there is a guide for the arc, isolated from the fixed contacts. The coils are electrically connected to the fixed contacts and the arc guide, respectively. Moving contacts are located on the contact bridge. The fixed contacts are located on copper plates, made stepped with an inclined transition from top to bottom from the location of the permanent magnets relative to their level in the area of the coils. Permanent magnets related to two contact - parts are polarized in opposite directions.

The arc that arises when the contacts are opened is displaced by the magnetic field created by a permanent magnet towards the arc guide and "jumps" onto it. Since the guide is electrically connected to the coil, the coil is excited and creates an electromagnetic arc suppression field, by means of which the arc is drawn into the arc chute and is extinguished there.

The disadvantages of the known technical solution are due to its design and are as follows:

- the implementation of the contactor with one arc chute significantly worsens the conditions for extinguishing the arcs formed when two contacts - parts are opened, (since both arcs are extinguished by one arc chute), which reduces the efficiency of arc quenching;

- the presence of only two guides for the arcs formed during the opening of the contact - parts of the arcs does not ensure the absorption of the thermal energy of the arc and does not make it possible to weaken it in order to facilitate the arc extinguishing, thereby reducing the efficiency of the device. Although the description talks about the formation of a guide channel between the main guides, it is actually very short (only between the short sides of the guides) and its presence does not significantly affect the efficiency of arc suppression. In addition, this design increases the potential for erosion of the contacts, which reduces their service life and thereby reduces the reliability of the device.

Known electromagnetic high-voltage contactor, which uses two arcing chambers with a gap in the center and a copper U-shaped guide installed between the chambers [2].

The known high-voltage electromagnetic contactor (1) operates on direct current and contains two contacts - parts (2, 3) with fixed contacts (4, 5), movable contacts (6, 7), which are located on the contact bridge (18), at least at least two permanent magnets (8, 9), placed near each contact - parts (2, 3) and designed to create a constant magnetic arc suppression field, and at least two coils (10, 11), placed near the contact - parts (2 , 3) and designed to create an electromagnetic arc suppression field for drawing in arcs (21, 22) arising when the contact - parts (2, 3) are opened, into two arc-extinguishing chambers (12, 13), and permanent magnets (8, 9), related to two contact - parts (2, 3), are polarized in opposite directions.

In this case, near each contact - part (2, 3), there is a guide (15, 16) for the arc, isolated from the fixed contacts (4, 5), and the corresponding coil (10, 11) is electrically connected to the corresponding fixed contact (4, 5 ) and the corresponding guide (15, 16) for the arc.

In addition, pole plates (25, 26) related to permanent magnets (8, 9) are located near the contact parts (2, 3).

In this case, pole plates (19, 20) located near the guides for the arc (15, 16) are associated with the coils (10, 11).

In addition, the contactor has a gap 14 between the interrupters.

In addition, two arc chambers are located near the guides (15, 16, 17) for the arc.

In addition, in the gap 14 between the two guides 15 and 16 and between the chambers 12 and 13, the third guide 17 is vertically arranged, made in the form of a U-shaped plate, reaching the upper part to half the height of the chambers, while the contactor body is collapsible.

The disadvantages of the known technical solution are due to its design and are as follows.

The implementation of the contactor with a copper U-shaped guide worsens the conditions for extinguishing the arc, excessive heating of the sides of the U-shaped plate occurs, thereby heating the central part of the contactor, which in turn reduces the wear resistance of the contactor as a whole.

The U-shaped plate is made of a scarce material such as "copper".

Thus, the main disadvantage of the known contactor is that it does not provide sufficient absorption of the thermal energy of the arc and does not provide an opportunity to weaken it in order to ensure reliable arc extinguishing, thereby reducing the efficiency of the device as a whole. The use of a material such as "copper" leads to an increase in the cost of the product.

The task is to reduce the heat generation during the arcing process, which will have a positive effect on the efficiency of arcing and the reliability of the contactor, and to reduce the amount of rare earth materials in the product.

The technical result is an increase in the efficiency of arc suppression and increase in reliability by reducing heat generation in the process of arc suppression, which in turn affects the wear resistance of the contactor parts and, as a consequence, the reliability of the contactor operation.

The problem is solved by the fact that a contactor assembled in a housing, operating on direct current, and containing two contact parts with fixed and one contact part with moving contacts, two permanent magnets placed near each of the contact parts and designed to create a permanent magnetic arc extinguishing field, and two coils placed near each of the contact parts and designed to create an electromagnetic field for drawing arcs arising when the contact parts are opened into the arc extinguishing chambers, while the movable contacts of the contact parts are placed on the contact bridge, permanent magnets, related to two contact-parts, are polarized in opposite directions, near each of the two contact-parts there is a guide for the arc, isolated from the fixed contacts, and the corresponding coil is electrically connected to the corresponding fixed contact and the corresponding guide for the arc, according to the utility model, there is a two dividing elements, vertically located in the gap between the guides and between the chambers, and made in the form of ceramic plates.

The introduction of two separating elements into the contactor, located between the two guides and between the two chambers, ensures effective dissipation of part of the thermal energy of the arc, weakening it and thereby facilitating the arc extinguishing, and also affects the efficiency of arc suppression. The introduced spacers were made of ceramics, which in turn reduces the amount of rare earth materials in the product.

The inventive contactor has a novelty in comparison with the prototype, differing from it in such essential features as the introduction of two dividing elements, vertically located in the interval between the guides and between the chambers, and made in the form of ceramic plates, which together ensure the achievement of the desired result.

The claimed utility model can be widely used in railway networks and locomotives for disconnecting loads and opening electrical circuits with high currents or high voltages, and therefore meets the criterion of "industrial applicability".

The utility model is illustrated by drawings, which are presented in:

FIG. 1 is a front view of the contactor with the housing removed;

FIG. 2 is a general view of the assembled contactor.

The contactor (Fig. 1 and Fig. 2) operates on direct current. It is assembled in case 1 and contains two contact parts 2, 3 with fixed contacts 4 and 5 and a bridge with moving contacts 6 and 7. Near each of the contact parts 2 and 3, there are two permanent magnets 8, 9 designed to create a permanent magnetic arc suppression field, and two coils 10 and 11, which are used to create an electromagnetic arc suppression field for drawing arcs. The arc chambers 12 and 13, located symmetrically relative to each other, are used to draw in arcs arising when the contact parts 2 and 3 are opened. At the same time, a guide 16 and 17 for the arc is located near each contact parts 2 and 3, isolated from the fixed contacts 4 and 5. Between the guides 16 and 17 and between the chambers 12 and 13, separating elements 14 and 15 in the form of ceramic plates are vertically located. The respective coils 10 and 11 are electrically connected to the respective stationary contacts 4 and 5 and the respective arc guide 16 and 17. Movable contacts 6 and 7 of contact parts 2 and 3 are located on the contact bridge 18. Fixed contacts 4 and 5 are located on plates 19 and 20, which are made stepped with an inclined transition from top to bottom from the area of arrangement of permanent magnets 8, 9 relative to their level in the area coils 10, 11. Permanent magnets 8 and 9 belonging to the two contact pieces 2 and 3 are polarized in opposite directions. The contactor housing 1 is collapsible.

The contactor works as follows. When the contactor is turned on, the electromagnetic drive (not shown in the drawings) raises the contact bridge 18 until the contact parts 2 and 3 are closed (fixed contacts 4 and 5 are in contact with movable contacts 6 and 7).

When the contactor is turned off, the return spring (not shown in the drawings) of the electromagnetic drive moves the contact bridge 18 downward. In this case, two electric arcs 21, 22 are formed on the silver contacts 4-7, which, under the influence of the Lorentz force arising from the permanent magnets 8, 9, begin to move in one direction (depending on the direction of the electric current flow). Arcs 21 and 22 are stretched, and one of them jumps to the guide 16 or 17, as a result of which an electric current begins to flow through the corresponding coil 10 or 11, and the coil 10 or 11 forms an electromagnetic field that draws the arc into the chamber 12 or 13, equipped with ceramic diffusers 23 , 24. Continuing to move, the arc 21 (22) hits the guide 16 or 17, as a result of which an electric current begins to flow in the second coil (10 or 11) and an electromagnetic field appears, pulling the arc into the second chamber 13 or 12. Separating elements 14 and 15 divides the arc (21 or 22) in two and dissipates some of the arc energy in the form of heat. Electric arcs 21, 22 under the action of the Lorentz force in both chambers 12, 13 move along the guides 16 and 17 to the ceramic diffusers 23, 24, where they give off the remaining energy in the form of heat and break, thereby opening the circuit.

In comparison with the prototype, the proposed contactor is more efficient in arc suppression and more reliable in operation.

Sources of information

1 Patent RU No. 2417475, IPC Н01Н 9/44, filing date 07.26.2007, publication date 02.10.2009.

2 Patent for utility model RU 162074, IPC Н01Н 9/44, filing date 08/05/2015, publication date 05/20/2016.

Claims (1)

High-voltage electromagnetic contactor operating on direct current, assembled in a housing and containing two contact parts with fixed and one contact part with moving contacts, two permanent magnets placed near each of the fixed contact parts and designed to create a constant magnetic arc suppression field, and two coils located near each of the fixed contact-parts and designed to create an electromagnetic arc suppression field in the arc-extinguishing chambers for drawing in and extinguishing arcs arising when the contact parts are opened, the movable contacts of the contact parts are placed on the contact bridge, permanent magnets related to two contact pieces, polarized in opposite directions, near each contact piece there is a guide for the arc, isolated from the fixed contacts, and the corresponding coil is electrically connected to the corresponding fixed contact and the corresponding guide for the arc, characterized in that about n is equipped with two dividing elements located vertically in the gap between the guides and between the chambers and made in the form of ceramic plates.

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