Abb Research Ltd.

Asea Brown Boveri Ag

Abb Schweiz Ag

Alstom Technology Limited

Abb Technology Ag

Thomas Schoenemann

Lukas Zehnder

Kurt Kaltenegger

Martin Lakner

Jean-Claude Mauroux

Jochen Kiefer

Marianne Pleines

Lutz Niemeyer

Markus Keller

Xiangyang Ye

Daniel Chartouni

Robert Anderes

Marc Mollenkopf

Christian Dahler

Stephan Grob

Olaf Hunger

Max Claessens

Leopold Ritzer

Bodo Bruhl

Lorenz Muller

Jorgen Skindhoj

Klaus-Dieter Weltmann

J&ouml;rg Peter

Ion Gavrilita

Patrick Huguenot

Peter Unternaehrer

Kurt Dahinden

Mercedes Dominguez Calvo

Gunter Speckhofer

Mercedes Calvo Dominguez

Christian Dähler

Zoran Andjelic

The disclosure relates to an electrical switching device, e.g., a generator circuit breaker, and to a method for improved switching-gas cooling. Gas jets are formed by a nozzle body in the exhaust area, are directed against a baffle wall and are swirled. The baffle wall is a component of the switching chamber enclosure and has a high thermal capacity and/or thermal conductivity, so that the switching gas vortices produce a highly efficient switching gas cooling on the baffle wall by turbulent convection. Exemplary embodiments relate inter alia to the design of the baffle wall and of the nozzle body. Advantages include: protection of the switching chamber enclosure against hot gases, improved switching gas cooling, and increased breaking capacity.

Generator circuit breaker with improved switching capacity

An exemplary isolating tube, and production method thereof, includes a mechanically load-bearing plastic tube composed of a fiber-reinforced polymer for use in a cooling element which can be loaded with high voltage, during whose operation the isolating tube forms an electrical isolation gap and in the tube interior carries an agent which flows as a liquid and/or vapor. The isolating tube can have a diffusion barrier which is held coaxially by the plastic tube. Such an isolating tube can be produced using an exemplary novel method for production.

Isolating tube for a cooling element which can be loaded with high voltage

The invention relates to an improvement to the thermal load capacity of generator switches (). As is known, radiation plates () are used between generator switches () for different phases (R, Y, B) for convective dissipation of radiated heat from adjacent encapsulation side walls (). According to the invention, in the vicinity of the encapsulation cover () of a generator switch (), the radiation plate () has at least one angled metal sheet () which is used to guide at least one air flow element () of the rising air flow () in the direction of the encapsulation cover () and in order to direct the flow along the encapsulation cover (). Exemplary embodiments include: radiation plates () electrically and thermally isolated from the housing (); radiation plates () with horizontally deflecting air guidance structures () on the inner face (); angled metal sheet () whose inclination is matched to a flattened area () on the encapsulation cover (); angled metal sheet () directed at cooling elements () on the encapsulation cover (). Advantages include: generator switches () with improved heat emission, increased rated current carrying capacity, and/or a more compact configuration.

Encapsulated switching devices having heat emission elements

In order to dissipate heat losses from the inner conductor (), the circuit breaker () having an elongated inner conductor () and an outer conductor () which surrounds the inner conductor () like a housing has at least one heat pipe () which extends from the inner conductor () to the outer conductor () and has an insulating hollow body () in order to form an electrical insulating gap (). The heat pipe () advantageously has a flexibly deformable section (). The heat pipe () can run in a supporting insulator () which supports the inner conductor (). In addition to a working medium, the heat pipe () advantageously also contains an auxiliary gas which results in an enhanced dielectric strength at low temperatures.

High voltage circuit breaker with cooling

The basis taken is a cooling element () made of a metal or of a metal alloy having at least one cooling rib () which is connected to a metal housing () for an operating means. The intention is to provide a cooling element () which has an improved cooling capacity. The inventive cooling element () is detachably connected to the housing () by means of fixing means. The cooling element () is provided with a thermally conductive and electrically insulating coating (), and it has the same electrical potential as the housing (), but carries no current.

Cooling element

The high-power switch () according to the invention, with at least one switch pole () for guiding and switching an electric current which flows in one current flow direction when the switch is in the closed state, with the at least one switch pole () containing an inner conductor () which carries the current and containing an outer conductor () which is connected to ground potential (G) and carries a return current in the opposite direction to the current, with the outer conductor () being in the form of a housing () which surrounds the inner conductor (), is characterized in that a cooling rib arrangement () which contains cooling ribs () is arranged on the outer conductor (). At least some of the cooling ribs are advantageously arranged on a separate part of the housing (), which is not the same as the part () of the housing () which is at a minimum distance from the inner conductor (). The cooling rib arrangement () advantageously has cooling ribs both outside the housing () and inside the housing ().

High-power switchgear with cooling rib arrangement

The switching device for switching high electrical currents and voltages has at least one switch pole () which is operated by means of a rotatable shaft (). Furthermore, the switching device has at least one lever system (), a first switching linkage () and at least one drive () with a drive rod (), with the rotatable shaft () being connected to the lever system (), the lever system () being connected to the first switching linkage (), and the first switching linkage () being operatively connected to the drive rod (). Movements of the drive rod () are converted to rotary movements of the rotatable shaft (). The physical space which is required for installation of the switching device is intended to be capable of being matched to the physical circumstances. This is achieved in that a transmission () which is connected to the first switching linkage () and a second switching linkage () which is connected to the transmission () and to the drive rod () are provided. This arrangement makes it possible to arrange the drive () such that physical circumstances, for example existing concrete edges, can remain, and the physical space which is required by the switching device can be minimized.

Switching device

A switching arrangement having a large burn-up reserve, contact fingers (,) are connected to a first electrical terminal via flexible bands (,) consisting of strips of, for example, copper which lie one above the other. The connecting portion (,) of the band (,), the said connecting portion adjoining the contact fingers (,) and being rigidly connected to them, is reinforced in each case by pressure welding of the strips. In the switch-off state, the bands (,) and, in part, the contact fingers (,) bear on an outwardly pointing supporting face (,), whilst, in the switch-on state, at least the contact fingers (,) and connecting portions (,) are lifted off from the supporting face (,), with the bands (,) being bent at the same time, as a result of contact with the outside of a switching pin (,) displaceable along a switching axis (,). The pressure force caused by electromagnetic attraction between the relatively short contact fingers (,) and the connecting portions (,), which in each case form an angle of approximately 30&deg; with the switching axis (,), approximately compensates the contact lift-off forces, whilst the forces acting on the flexible parts of the bands (,) are absorbed essentially by the supporting face (,).

Burn-off contact arrangement

In a power switch, power-switch fingers of a rated-current switching arrangement, as well as contact fingers (,) of a tulip contact and a switching pin (,) of an arcing switch arrangement, or other parts, each comprise a base body (,) which, at sections which are subjected to high thermal loads by the arc formation, bears a protective layer (,) which is resistant to contact erosion and has been applied to the base body (,) by plasma spraying in vacuum. This enables even complex and flexible parts to be made resistant to contact erosion. The protective layer (,) which is preferably used is a mixture of at least 10% (by weight), in particular at least 50% (by weight) of high-melting metal, such as W, Mo, Ir, and lower-melting metal, such as Cu, Ag, Ti, Fe, e.g. 80% (by weight) W and 20% (by weight) Cu, while the base body used is preferably made from Cu, Ag. Fe, steel, Al or a flexible copper alloy, such as CuBe, CuCr or CuCrZr.

Switching arrangement and method for its production

Arranged in the continuation of an arcing chamber (16) bounded by consumable rings (32a, 32b) are pressure chambers (25a, 25b) which are connected in each case to a heating volume (18), which concentrically surrounds the arcing chamber (16), via a return channel (28; 28b), which is rotationally symmetrical with reference to the switching axis and is at least initially of increasing cross section, and a non-return valve (29a; 29b). A circumferential blowout slot (19) opening into the arcing chamber (16) between the consumable rings (32a, 32b) issues from the heating volume (18). The pressure chambers (25a, 25b) are, moreover, connected via in each case a plurality of exhaust tubes (34a, 34b) to exhaust volumes (30a, 30b) and to one of them also via a pressure relief valve (37). The pinch pressure produced between the consumable rings (32a, 32b) during formation of an arc (17) leads to a pressure buildup in the pressure chambers (25a, 25b) which contributes via the return channels (28a, 28b) to building up in the heating volume (18) a high blowout pressure which on the occasion of the next zero crossing causes a strong gas flow through the blowout slot (19) into the arcing chamber (16), which quenches the arc (17).

Puffer type circuit breaker with arcing chamber, auxiliary shunting

Extending between a fixed tulip contact (1) and a slide tulip (4) is an arcing chamber (5) which is occupied in the closed position by a movable contact pin (3) which fills up both an exhaust (9) surrounded by the slide tulip (4) and a blowout opening (7) which is surrounded by the tulip contact (1) and connects the arcing chamber (5) to a pressure chamber (6). The arcing chamber (5) is surrounded by an annular heating volume (13) open toward the same. Arranged in the pressure chamber (6) is a charge (10) of explosive which is for the most part converted within approximately 10-30 ms after ignition to extinguishing gas, preferably predominantly nitrogen, the gas pressure moving the contact pin (3) toward the open position. After clearance of the blowout opening (7) and the exhaust (9), the arc drawn between the contact pin (3) and tulip contact (1) is blown out, something which is supported by the pressure buildup, to which the arc contributes, in the heating volume (13). The pressure chamber with the charge can also surround the arcing chamber in an annular fashion. In this case, it is also possible to support the opening movement by the explosion pressure, for example, via pistons.

Circuit-breaker with an explosive charge ignited during opening operation

In the switched-on position, under the influence of contact forces generated by elastic deflection or else by mechanical spreading, or spreading caused by the attraction of parallel currents or repulsion of antiparallel currents, of a switching pin (5) , the switching pins presses against the inner side of a first switching ring (4), which is rigid for the purpose of avoiding mechanical overloading and securing sufficient consumable reserves. By way of example, a support (30) of the switching pin (5) is adjoined by two parallel, elastic extensions (52a, 52b), which are separated by a slot (53) and respectively support a contact member (54a; 54b) by means of a connecting element (55a; 55b) forming half a screw thread, with the result that said contact member is in each case offset by 180.degree. relative to the extension (52a; 52b). In the switched-on position, therefore, the contact members (54a, 54b) are forced apart by the elastic deformation of the extensions (52a, 52b) which is caused by the attraction between the parallel partial currents through said contact members. The switching pin (5) is electrically conductively connected to a second switching ring (6), which is separated from the first switching ring (4) by an arc space.

Consumable switching arrangement

A wreath of contact fingers (4) directed radially toward a switching axis (1) presses in the closed position against the circumferential surface of a contact pin (2) with consumable heads (5) fitted on the ends. At an angle of approximately 90.degree., the contact fingers (4) adjoin webs (6) which are guided in the closing direction up to a housing part (7) at which they are permanently anchored and via which they connect the contact fingers (4) to an electric terminal. The webs (6) and--with the exception of the consumable heads (5)--the contact fingers (4) are produced in one piece from springy material of high conductivity. The contact with the contact pin (2) radially deflects the consumable heads (5) in the closing direction with elastic bending of the webs (6). The length (R) of the radial contact fingers and the length (L) of the axial webs (6) are selected such that the attraction of the parallel component currents through the latter approximately compensates the contact repulsion forces.

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Schafisheim, Switzerland

Thomas Schoenemann