Bbc Brown, Boveri & Company, Limited

Asea Brown Boveri Ag

Abb Management Ag

Asea Brown Boveri Inc.

Ernst Brem

Peter W Stadelmann

Roland Ulrich

Josef Tommer

Josef Merki

Hansjurg Rohrer

An electrical machine (,), in particular a generator, comprises a rotor (,) with pole zones, in which pole zones amortisseur bars (,) designed as wedges are arranged, which amortisseur bars (,), on the outside of the rotor (,), are pushed into slots (,) provided for this purpose and running in the longitudinal direction and are held in the slots (,) by supporting means (,) against the centrifugal forces occurring during rapid rotation of the rotor (,) and which are connected to one another in an electrically conductive manner at the ends of the rotor (,) by an amortisseur ring (,) or amortisseur segments (,), which enclose the rotor (,) in an annular or ring-section-shaped manner. In such a machine, reliable fixing and electrical bonding of the amortisseur bar in the slot when the machine is stopped and at low rotational speeds with at the same time ease of fitting is achieved in that prestressable spring elements (,) are arranged in a distributed manner on the underside of the amortisseur bars (,), which spring elements (,), in the prestressed state, enable the amortisseur bars (,) to be pushed into the slots (,) without hindrance and, after the prestressing has been removed, press the amortisseur bars (,) against the supporting means (,) and at the ends of the rotor (,) against the amortisseur rings (,) or amortisseur segments (,).

Electrical machine with a rotor provided with amortisseur bars

An arrangement for providing exciter current in the rotor of an electric machine. The rotor winding is connected to the slip rings by exciter current conductors which are arranged in pairs in a central shaft bore of the rotor. The slip rings are arranged on a shaft stub which is connected to the rotor shaft with a releasable coupling. The central shaft bore includes bolt-side connection elements into which radially extending current supply bolts are releasably attached. The exciter current conductors are metallic pipes with an orbicular cross-section which are connected permanently at the other end to solid coupling-side connection elements. The ends of the connection elements penetrate a sealing plate in the coupling and are electrically insulated therefrom. Sealing rings are used to seal the sealing plate with respect to the rotor shaft and the ends of the coupling side connection elements which penetrate the sealing plate.

Exciter current line in the rotor of an electric machine

A combined installation configured as a single-shaft installation with common shafting (1) consists essentially of a gas turbine, a steam turbine, the generator (10), which is located between them, and the associated auxiliary systems (12). The generator (10) and the associated auxiliary systems (12) are arranged on a slab (8) which can be displaced transverse to the common shafting (1).

Method of servicing generator in combined cycle power plant

Combined installation for gas and steam turbines

In an electrical machine with horizontal axis, an elastic suspension of a laminated stator core, which deforms under the influence of the rotating magnetic field, is achieved by supporting the laminated stator core at a housing only in the area of the vertical plane of symmetry (V) and supporting the housing on a foundation only in the area of the horizontal plane of symmetry (H).

Electrical machine with horizontal axis and resilient support of stator

In turbo-generators with hydrogen-cooled rotor windings, one-piece end casings are used to avoid complicated sealing positions. These end casings are strongly ribbed in a radial direction and present difficulties when installing the shaft seal (19). Furthermore, they do not permit any inspection openings in the ribbed end casing. Both have the final result of causing an increase in the machine length. Due to the pot-type design of the end casing (1) with a vertically extending channel-type recess (9) having a width greater than the rotor outer diameter, the assembly of the splert ring (19) is facilitated. The channel walls (7, 8) stiffen the end casing and provide niches which are accessible from the end face of the machine via inspection openings.

Casing means for electrical machine

The laminated stator body of a large turbo-generator consists of a stack of laminations (1) comprising laminated compression plates (2), which stack is clamped together by means of tie plates (3) and tension bolts (8). The end face of the compression plate is stepped in the axial and radial direction. The tie plates have either a contour which matches the outside contour of the compression plate (2) or are smooth and, in the latter case, are supported by arch pressure in the radial direction. The elaborate machining of the compression plate end face, resulting in the elimination of lamination shorts, can thus be omitted without impairing the electrical and magnetic effects of the laminated compression plate on the end field of the machine.

Stator body with laminated compression plates

In a large turbo-generator comprising a laminated stack (6) which has on its outside axial grooves (7) which are distributed over the entire circumference and which is there suspended in a housing (1) by wedges extending in its longitudinal direction, the wedges (8) are joined to a wedge carrier (4) which extends parallel to them and is fixed at the housing (1). The wedges are constructed of several parts and have a central center part (8) which is detachably connected to the wedge carrier (4) and which is essentially used for radial support. As support in the circumferential direction, clamping devices, for example in the shape of double inclined wedges (9a, 9b) are provided which are arranged in pairs between the groove side walls and the wedge center part and which are located completely inside the groove (7) and which can be actuated from the front of the completely laminated stator. In this manner, mounting openings in the housing (1) become superfluous and laminating is facilitated.

Electric machine

The connecting device has yokes (5, 6) brazed to the winding rod ends (1, 2), and the end surfaces of the yokes have distance pieces (10, 11, 12, 13). The hollow conductors (4) protrude beyond the solid part conductors (3) and are led through brazing plates (14, 15) which are brazed to both the hollow conductors (4) and the distance pieces (10, 11, 12, 13). Caps (16, 17) are placed over the brazing plates (14, 15) and brazed to the brazing plates (14, 15) in such a way that there is no leakage of liquid. The brazing points can be inspected at any time and, if necessary, improved because of the distance between the brazing plates (14, 15) and the rod end surface. The water chambers (20, 21) formed by the brazing plates (14, 15) and the caps (16, 17) are solidly connected to the winding rods (1, 2) and to the yokes (5, 6), so that no relative vibrations, which can damage the hollow conductors, can occur. The water chambers (20, 21), which are expensive in manufacture, do not depend on the rod geometry. The whole of the variance is provided by the brazing plates (14, 15) which are relatively simple to manufacture.

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Schlieren, Switzerland

Ernst Brem