EP1026714B1 - Quenching coil for gas-insulated load-break switches or circuit breakers - Google Patents

Abstract

The blowout coil has a cylindrical coil body (1), a conductor winding and an insulating film between the winding layers. The start of the winding is fixed to the coil body and electrically contacted to it. The winding is held together by a clamp (4) which is electrically contacted to the end of the winding. The start and immediately following part of the first winding layer (2a) is flat and bare, lying on the peripheral surface of the coil body. This part alone is connected mechanically and electrically to the coil body by the external clamp (4) and the force it produces on the winding. An Independent claim is included for a method of manufacturing a blowout coil.

Description

The invention relates to a quenching coil according to the arc-rotation principle for use in gas-insulated, in particular SF ₆ gas-insulated load disconnectors or circuit breakers for switching off currents in medium-voltage switchgear.

It is known in gas-insulated medium-voltage switchgear switch-disconnector or circuit breaker whose phases to ensure switching capability with quenching coils are equipped. The switching ability is u.a. thereby ensuring that the at Switching the switch between the fixed contact and the movable switching contact the each arc is kept as small as possible and quickly extinguished, so that a burn on the contacts is largely avoided. The quenching coils usually consist of a metallic annular coil core with one on this applied single or multi-layer winding. The resulting arc is in the Coil core conducts and rotates in the winding, before it through the resulting magnetic field is cleared. The arc rotation is with a high cooling and Deionisationswirkung connected.

The bobbin of the quenching coil consists of a non-magnetic material and the Winding usually made of a copper tape with a film insulation (foil tape) between the band layers, wherein the beginning of the copper strip, preferably by soldering, riveting or screws is mechanically and electrically connected to the bobbin. The Copper tape winding is characterized by a with the copper band end electrically contacted clamping element, usually a clamp, held together.

The mechanical connection between the beginning of the copper band and the cylindrical one Bobbins by soldering, riveting or screwing can damage the copper tape layers and to reduce the magnetic field and thus to a deterioration of Arc rotation and extinguishing power lead. At high currents can also Spool in the said connection area due to the strength reduction given there collapse and collapse. Moreover, these are the bonding techniques mentioned consuming.

From DE 38 82 186 T2 (or US 4 918 268 A) is a magnetic blown coil with arc rotation (quenching coil) for the switching element of an electrical switch known. This has an electrically conductive Coil core and a winding arranged on this from a flat ladder on, wherein the beginning of the first turn is firmly connected to the bobbin and the Windings applied together with an insulating film in several turns on this are. The core has an axial gap in which a pad is inserted, with the the beginning of the turn bears against a substantially radially aligned gap wall. The winding is of a split ring made of a plastically deformable metal surrounded, with the end of the last turn through the gap and between the Ring and a surrounding housing is guided. The coil is in the housing in radial Strained direction, causing them mechanically and electrically fixed to the bobbin and the housing is connected.

The quenching coil is expensive because its mounting, including the attachment of the two Ends of the winding, consuming and without pressing tool is not feasible. moreover the coil core is reduced by the introduced radial gap in its strength.

It is therefore an object of the invention to provide a quenching coil according to the preamble of the claim 1, which is mechanically strong even at high currents and those with a reduced technological effort can be created.

This object is in a quenching coil according to the preamble of claim 1 by the Characteristics solved. Advantageous embodiments and a method for Production are formulated in the subclaims.

The invention is that in a quenching coil, a metallic, cylindrical Spool, a winding of an electrically conductive metal and an insulation between having the winding layers, wherein the beginning of the winding on the bobbin fixed and electrically contacted with this and the winding by a with the Winding end electrically contacted clamping element is mechanically held together, the beginning and an immediately following part of the first winding layer flat and blank rests on the bobbin and this part only by the outer clamping element and the pressure generated by this on the winding mechanically and electrically fixed with is connected to the bobbin. This coil construction, in which a complex connection technology for fixing the beginning of the winding on the bobbin by rivets, screws or by soldering, ensures the mechanical strength of the bobbin, so that this also withstands high mechanical stress caused by high currents. moreover also damage to the winding by screws or rivets is avoided, so that the arc rotation is unimpaired.

To produce an electrically fixed connection, half the first winding layer can be bare rest on the bobbin. Also, the last half winding can be wound back.

In the usual way, as a clamping element, a metallic band, for example a clamp made of steel, which are wrapped around the winding and by screwing elements is tightened, whereby the winding with the insulation, preferably a Isolierfolienband compressed and a sufficient mechanical and electrical contact pressure are generated.

To produce a quenching coil according to the invention, the beginning of the first winding layer fixed by means of adhesive tape on the bobbin and this immediately following Part of this first winding layer, preferably half the first winding layer, wound up blank. At the end of this part, the beginning of an insulating foil tape is interposed and then wound up this and the other winding layers. After this Winding the other winding layers are repulsed part of the last winding layer and then the metallic band (steel clamp) placed around the winding, tightened and thereby compressed the winding.

Fig. 1:

die Struktur einer Löschspule in einer Ansicht quer zur Spulenachse,

Fig. 2:

den Wicklungsanfang auf dem Spulenkörper,

Fig. 3:

das Wicklungsende und

Fig. 4:

eine Ansicht von Löschspule und Schaltmesser.

The invention will be explained below with reference to an embodiment. In the accompanying drawings is shown schematically:

Fig. 1:

the structure of a quenching coil in a view transverse to the coil axis,

Fig. 2:

the beginning of the winding on the bobbin,

3:

the winding end and

4:

a view of extinguishing coil and switch blade.

The extinguishing coil shown in Fig. 1 has a bobbin 1, a arranged on this Wrapping 2 of copper tape with several tape layers, of which only two layers shown are, between a part of the first band layer 2a and the bobbin 1 and between the band layers arranged plastic film 3 for insulation and a clamp 4 steel with a screw 5 on, through which the winding 2 on the bobbin 1 is pressed. The foil insert between the first band layer 2 a and the bobbin 1 begins after the first half band layer 2a, which rests bare on the bobbin 1, and ends after the last band position 2b. This is half repulsed, with the folded back half bare on the other half of the last band layer 2b rests.

In Figs. 2 and 3, the beginning and the end phase of the tape winding are shown. Of the Beginning of the first band layer 2a is, for example, with an adhesive tape strip (not shown) fixed on the bobbin 1. Thereafter, the first band layer 2a is half (approx. 180 °) blank in winding direction A wound. After this half will be the beginning of the plastic film 3 inserted between the bobbin 1 and the first half band layer 2a, and it is the winding of the copper strip continued until all tape layers, each with underlaid Plastic film 3 are achieved. The last band layer 2b is halfway up (about 180 °) the winding back over the film 3 (winding direction B in Fig. 3). On the after outside bare winding, whose end is denoted by E, eventually becomes the clamp 4 arranged.

4 is a three-position power switch with a metallic contact blade 11, a fixed contact 12 and the extinguishing coil 1 according to the invention. That the switching contact forming contact blade 11 is about an axis S between the fixed contact 12 and a ground potential contact, not shown, pivotally mounted. On the contact blade is articulated a connecting rod 14, which via a (not shown) rocker arm of a (Also not shown) switching shaft is actuated. The contact blade 11 has at its free end of a corresponding to the fixed contact 12 contact surface 18. The Contact surfaces are formed in a plane perpendicular to the pivot axis S. The contact surface 18 is designed high-temperature resistant to the thermal stress of the arc to be able to withstand. The movement of the switch blade is indicated by the arrows P1 and P2 indicated. The arrow P1 points in the direction of the ground potential contact; the arrow P2 points in Direction to the fixed contact (ON position). During the movement from ON to OFF the switch blade pulls the switching arc behind and dives into the extinguishing coil 1 one. Fig. 1 is a view of the quenching coil in the direction of arrow An. The clamping elements the winding 2 are indicated by the reference numeral 5.

Claims (5)

1. A quenching coil for use in gas-insulated load-break switches or circuit breakers, the phases of which have a fixed and a movable contact, comprising a cylindrical coil former (1), an electrically conductive winding and a film (3) for providing insulation between the winding layers, wherein the start of the winding is secured to the coil former (1) and is in electrical contact therewith, and the winding (2) is mechanically held together by a clamping component (4) which is in electrical contact with the end of the winding, characterised in that the start and an immediately following part of the first winding layer (2a) lie flat and uninsulated on the circumferential surface of the coil former (1), and in that this part is mechanically and electrically fixedly connected to the coil former (1) solely by the outer clamping component (4) and the pressure generated by it on the winding (2).
2. A quenching coil according to claim 1, characterised in that half of the first winding layer (2a) lies uninsulated on the coil former (1).
3. A quenching coil according to claim 1, characterised in that part, preferably half, of the last winding layer (2b) is folded back.
4. A quenching coil according to claim 1, characterised in that the clamping component (4) is a metal band, the ends of which are drawn together by screw components (5) so as to generate pressure.
5. A method of manufacturing a quenching coil according to any one of claims 1 to 4, characterised in that the start of the first winding layer (2a) is adhesively fixed to the coil former (1), and an immediately following part of this first winding layer (2a) is placed flat and uninsulated onto the coil former (1), in that the start of an insulating film strip (3) is interposed at the end of this part, and then the film strip (3) and all further winding layers are wound on, in that part of the last winding layer (2b) is folded back over the end of the film strip (3), and then a clamping component (4), preferably a metal band, is placed around the winding, and the winding (2) is pressed onto the coil former (1).

Images