WO2010098699A1

WO2010098699A1 - Device for integration of the movable current collector in the vacuum arc - quenching chamber with a circuit breaker terminal

Info

Publication number: WO2010098699A1
Application number: PCT/RU2010/000093
Authority: WO
Inventors: Alexei Mikhailovich Chaly; Andrei Petrovich Minaev; Vyacheslav Nikolaevich Gorelov
Original assignee: Tavrida Electric Industrial Group
Priority date: 2009-02-27
Filing date: 2010-02-27
Publication date: 2010-09-02
Also published as: RU2009106744A

Abstract

The device for integration of the movable current collector in the vacuum arc-quenching chamber with a circuit breaker terminal of commutation apparatus (a flexible current collection) comprises a moveable contact, which is mounted with a capability of translation displacement, and a fixed contact. These contacts are connected with a pack of preliminary bent commutator segments 3. The contacts are made in the form of copper coaxially mounted immoveable outer and moveable inner slugs (1,2). The segments 3 are uniformly distributed over the perimeter of the slugs 1,2 and each of them is pressed with one end into the outer slug 1 and with the other end into the inner slug 2. The technical result is a reduction of dimensions, an improvement of life duration and durability of the device by means of uniformly bending and exclusion a breaking of the segments, the fixation of which by means of non-detachable connection does not require the device locking, an enhancement of amplitude of reciprocal displacements of the contacts (up to 12 mm) and the current-carrying capacity by means of optimal configuration of electrical fields, which are formed by the current collection.

Description

Device for integration of the movable current collector in the vacuum arc - quenching chamber with a circuit breaker terminal

Field of the invention The invention relates to the field of electrical engineering especially to realization of electrical connection between the objects one of which reciprocates relative to the other. Here the case in point is to provide passage of electric current between a movable terminal of the arc quench chamber (hereinafter VAC) and other current-carrying circuits of the switching device with a flexible current collector. Realization of such electrical integration is a complicated technical task as such integration should satisfy a number of contradictory requirements. For example, in order to not hinder the drive operation providing fast movement of the movable elements of VAC for current switching the flexible current collector should possess relative low rigidity and mass. At the same time, the current collector should have low intrinsic electric resistance; however, this can be achieved at the cost of increasing the cross-section of the current collector, and, therefore, leads to increase in its mass and rigidity. Moreover, increase in the collector dimensions may cause deterioration of dielectric strength of the deice — both interphase and relative to the earthed structural elements. Integration between the current collector and a movable terminal of VAC, on one hand, and with the static current-carrying elements of the switching device, on the other, should have low transition resistance and significant (tens thousand cycles) mechanical durability.

There exists considerable number of constructions adapted for realization of electric connection between movable and static parts of machines and devices. However, most of them (See, for example, SU JNI.503304 or SU JN°639064), are weak- current constructions and cannot be used in, or adapted for circuits with nominal currents of hundreds and thousands amperes. Other constructions (for example, those disclosed in SU .N°792388 or SU JNT°796964) are designed for electric machines wherein a movable part rotates around the static one. Such solutions cannot be applied in the case of reciprocating motion of movable elements.

High current constructions are known that serve for electric integration in the case of translational movement. For example, a module of the vacuum contactor or vacuum circuit breaker including a vacuum arc quenching chamber where upper and lower current collectors, electric magnet, supporting insulator, insulating traction, connection and compression springs, limiter, and interlocks are aligned. The said module includes a movable contact 4 which can slide and a static contact 5 connected with a flexible current collector in the form of packed commutator segments which preliminary were bent (not shown in the drawing), the ends thereof are jammed on the mating contact points (See RU N°36566, the prototype).

The drawbacks of this device (flexible current collector) are caused by the following:

•Sharp side faces of the contacts forms zones of increased electric field strength and may serve as a source of discharge activity under overvoltage test. Control of this phenomenon requires application of barrier insulation or increasing the insulating gaps.

•Elevation of transmission capacity of the current collector due to increasing the thickness of the pack of tightly compressed commutator segments would lead to increase in rigidity of the current collector which would affect energy consumption of the drive or cause deterioration of temporal characteristics (for example, operation speed) of the device.

•When the number of cycles is large thin commutator segments comprising the current collector can be destructed near the zone of sharp break that may increase the circuit resistance and promote discharge activity due to additional sharp edges. 'Presence of screw connections at the points of connections with contacts forced one to take care about locking elements as operation of the switching device is accompanied by vibrations and high-frequency mechanical oscillations occuring over pole of the device.

As a result, the known device should have increased dimensions adapted for high nominal current providing the amplitude of free movement of a movable element (in this case - VAC contact), have insufficient mechanical durability and non-optimal configuration from the viewpoint of electric fields created by the current collector.

Presence of the above limitations forced one to search other solutions for integrations of movable and static parts of electric devices. The technical task of the invention is development of an efficient device for integration of the movable current collector of the vacuum arc quench chamber with the terminal of switching device and broadening of the stock-in-trade devices for integration of the movable current collector with the terminal of the switching device. The technical result providing solution of the set task lies in reducing dimensions, increasing durability and reliability at the cost of equal bend of all the commutator segments and their uniform distribution over the perimeter, preventing their break, and fixing them with nondetachable connection that requires no locking, broadening the amplitude of relative motion of the contacts (up to 12 mm), increasing the acceptable value of current at the cost of the optimum configuration of the electric fields created by the current collector as the zones of elevated field strength are absent, rigidity of the flexible connection is minimal, and zone of sharp break are absent. Concept of the invention lies in the fact that a device for integration of the movable current collector of the vacuum arc quench chamber includes a movable contact which may reciprocate and a fixed contact connected with a pack of preliminary bent commutator segments characterized in that the contacts are manufactured in the form of coaxially aligned static outer and movable inner slugs, and commutator segments are manufactured of copper foil and are distributed uniformly over the perimeter of the slugs and each of them is pressed with one end into the outer slug, and with the other end into the inner slug.

In the particular embodiments the commutator segments are pressed into faceted recessions in the slugs according to the number of the commutator segments . Preferably the slugs are manufactured of copper, and commutator segments are manufactured of copper foil 0.04-0.06 mm thick and 8-12 mm wide; are installed loosely by forced imparting them a possibility of free travel relative to each other, the inner slug has an opening and a groove with a tapered profile; the outer slug may be pressed into a cylindric well of the terminal designed for electric connection of the switching device with external circuits; the inner slug may be integrated with a terminal of movable electrode of the vacuum arc quench chamber , moreover , the inner slug has an opening to receive a stud for fixing at the movable electrode with a tapered groove for tapered seating.

The claimed flexible current collector for VAC is a part of vacuum circuit breaker (Patent of an invention RU 2249874) and is an integral part of the patent.

Int the drawing Fig.l the general view of the device (a flexible current collector) is shown for integration of the vacuum arc quench chamber with the terminal of the switching device, in the Fig.2 — example of installation of the flexible current collector in the terminal of switching device).

The integration device of the movable current collector of the arc quench chamber (a flexible current collector) with the terminal of the switching device includes a movable contact 2 which may reciprocate and a fixed contact 1 connected with a pack of preliminary bent commutator segments 3. The contacts are manufactured in the form of copper coaxially aligned static outer slug 1 and movable inner slug 2. The commutator segments 3 are manufactured of copper foil and are distributed uniformly over the perimeter of the slugs 1 ,2 and each of them is pressed with one end into the outer slug, and with the other end into the inner slug 1,2, respectively.

Flexible commutator segments 3 composed of the copper foil 0.05 mm thick and 10 mm wide the number of which (and diameters of the said slugs) is defined by required current parameters of the current collector, are pressed into annular grooves of the slugs 1 ,2 made along the generatrix or into faceted recessions in the slugs 1 ,2 according to the number of commutator segments 3 (not shown). The inner slug 2 has an opening and a groove 4 of the tapered profile. The inner and outer slugs 1,2 may travel relative to each other along the common axis in a relatively wide range of distances with the steady and minimum force applied for movement. That is provided, particularly, by preliminary loosening of the commutator segments 3 at the stage of their technological preparation, that is, the commutator segments 3 are installed in the loosen state by forced imparting them a possibility of free travel relative to each other. The outer slug 1 may be pressed into a cylindric well of the terminal 5 adapted for electrical connection of the switching device with external circuits. The inner slug 2 may be integrated with a terminal of the movable electrode of the arc quench chamber (not shown). To this end, the inner slug 2 has an opening to receive a stud for fixing at the movable electrode with a groove 4 for tapered seating (not shown).

The claimed flexible current collector is designed for application as a part of the vacuum quench chamber (VAC) of the vacuum circuit breaker (not shown), disclosed in the RU N°2249874, and is an integral part of the patent.

The device for integration of the movable current collector of the vacuum arc quench chamber with the terminal of the switching device (flexible current collector) operated as follows . The terminal 5 manufactured of aluminum alloy of the device includes a cylindric well of the diameter matched with the outer diameter of the outer slug 1 of the current collector for forced fit . After the outer slug 1 is pressed into the well of the terminal 5, cold welding is formed between the surface of the slug 1 and the surface of the well which provides the minimum transition resistance. The inner slug 2 over the tapered fit of the groove 4 seats on the movable terminal of the VAC and is tighten down with a stud which passed through the opening in the slug 2. A traction insulator integrated with a drive of the switching device is fixed to the other end of the stud (not shown). With operation of the latter, current collecting is carried out by the following path: terminal 5 - outer slugl - commutator segments 3 - inner slug 2 - movable current collector of the VAC. The flexible commutator segments 3 in this embodiment allows traveling the slugs relative to each other, that is, provide the amplitude of relative motion of the contacts up to 12 mm.

Thus, and efficient flexible current collector is developed — a device for integration of the movable current collector of the vacuum arc quench chamber with the terminal of the switching device, and stock-in-trade devices was broadened for integration of the movable current collector of the vacuum arc quench chamber with terminals of the switching device.

Dimensions were reduced, durability and reliability were increased at the cost of equal bending all the commutator segments and uniform distribution of all the commutator segments over the perimeter, preventing their breaking, and fixing them on with nondetachable connection which requires no locking, the amplitude of relative motion of the contacts was increased (up to 12 mm) (, acceptable value of current was increased at the cost of the optimum configuration of the electric fields created by the current collector, as the zones of elevated field strength are absent, rigidity of the flexible connection is minimal, and zone of sharp break are absent .

Combined trials of the claimed device were performed at "Tavrida Electric" test center. The results of the trials confirmed the technical results and validity of selected technical and technological decisions.

Claims

1. The device for integration of the movable current collector in the vacuum arc- quenching chamber with a circuit breaker terminal including a movable contact which may reciprocate and a fixed contact connected with a pack of preliminary bent commutator segments characterized in that the contacts are manufactured in the form of coaxially aligned static outer and movable inner slugs, and commutator segments are manufactured of copper foil and are distributed uniformly over the perimeter of the slugs and each of them is pressed with one end into the outer slug, and with the other end into the inner slug.

2. Device according to claim 1, characterized in that the commutator segments are pressed into annular grooves in the slugs.

3. Device according to claim 1 characterized in that the commutator segments are pressed into faceted recessions in the slugs according to the number of the commutator segments.

4. Device according to any of the claims 1-3 characterized in that the slugs are manufactured of copper, and commutator segments are manufactured of copper foil 0.04-0.06 mm thick and 8-12 mm wide.

5. Device according to any of the claims 1-3, characterized in that the commutator segments are installed loosely by forced imparting them a possibility of free travel relative to each other.

6. Device according to any of the claims 1-3, characterized in that the inner slug has an opening and a groove of tapered profile.

7. Device according to any of the claims 1-3, characterized in that the outer slug may be pressed into a cylindric well of the terminal adapted for electrical connection of the switching device with external circuits.

8. Device according to any of the claims 1-3, characterized in that the inner slug may be integrated with a terminal of the movable electrode of the arc quench chamber.

9. Device according to claim 8, characterized in that the inner slug has an opening to receive a stud for fixing at the movable electrode with a tapered groove for tapered seating.