Westinghouse Electric Corporation

Electric Power Research Institute Incorporated

Carl Flick

Richard D Nathenson

Sui-Chun Ying

A pancake armature winding in which the turns of each phase coil are insulated to withstand turn-to-turn voltage potential has phase-to-phase insulation provided by inner and outer insulative skins which act cooperatively with insulative filler pieces which also provide mechanical support for the phase coil. The reduced amount of insulation on each turn of the phase coil permits the overall size of the pancake coil to be reduced. The armature winding is supported mechanically by inner and outer insulative cylinders.

Spiral pancake armature winding module for a dynamoelectric machine

A support structure for unitizing coil turns into a single member and bracing each coil of a multi-coil stator dynamoelectric machine. Each stator coil includes several turns relatively concentrically disposed. Each coil turn constitutes two longitudinal conductor portions and two end turn conductor portions. One end turn portion serially connects two longitudinal portions and the remaining end turn portion serially connects one of the longitudinal portions with a longitudinal portion of a concentrically adjacent coil. Each coil preferably lies in a plane defined by a portion of a cylinder and the coils are disposed in a cylindrical arrangement having a longitudinal axis therethrough such that one longitudinal portion of the outermost coil turn lies along the outer radial extent of the cylindrical arrangement and the remaining longitudinal portion of the outermost coil turn lies radially nearer the longitudinal axis of the cylindrical arrangement. A rigid foundation member is situated in the plane of each coil within the concentrically innermost turn. Turns of each coil are structurally connected either directly to the foundation member or indirectly to the foundation member by being intermediately joined to a turn already joined to the foundation member. The concentric turns of each coil are separated by a predetermined distance through the use of interposed spacer members situated at desired axial and circumferential locations. Such coils present a spiral pancake appearance and are cooperatively disposed in the cylindrical arrangement between radially inner and outer supporting structures. Appropriately shaped wedges are disposed between selected coils and internal/external supporting members to account for the skewed or spiral manner in which each of the coils is arranged in the substantially cylindrical arrangement. Radial tie rods extending between the radially internal and external support members structurally integrate those members so as to insure structural integrity of the cylindrical arrangement. The radially external support member is preferably configured to extract load components from individual coil turns exposed at the cylindrical arrangement's outer periphery by either having radially inwardly directed struts extending between adjacent turns or having notches within which the radially outer conductor turns, when canted, are receivable.

Support structure for dynamoelectric machine stators spiral pancake

Surface currents are induced in dynamoelectric machine rotor body portions by negative sequence currents during unbalanced load operation. The surface currents are shunted away from retaining rings which are respectively situated on opposite axial ends of the rotor and function to restrain radial movement of conductor end turn portions which extend axially beyond the rotor's body portion. The retaining rings are shrink fitted on both ends of the rotor's body portion so as to structurally extend that body portion in both axial directions. Shunting the rotor surface currents away from the retaining rings provides an operating temperature therein of sufficiently low level to maintain high electrical joint integrity between the retaining ring and rotor. A mantle of highly conductive material surrounds both retaining rings in intimate electrical contact therewith. The mantle thickness is at least one-half depth of electrical current penetration for the rotor surface current's frequencies. The mantle is electrically connected to the rotor body portion preferably through interference fits with radial extensions of slot wedges which are situated in longitudinal slots formed in the rotor body radially outside electrical conductors disposed in those slots. The wedges constitute electrically conductive material and provide longitudinal electrical conductor retention in the rotor slots during high speed rotor rotation. Components joined through the interference fit include the mantle and the wedges' radial extensions. A material softer and of higher electrical conductivity than either of those joined components is preferably interposed as a plating material on either or both components.

Dynamoelectric machine having shielded retaining rings

A rotating electrical machine having a winding configuration and insulating system permitting very high voltage operation. The phase coils of the armature winding are arrayed in outwardly spiralling paths about the rotor. Smooth and continuous interphase spaces are formed between the coils for containment of interphase insulating layers. Each interphase layer comprises laminated sheets of permeable material impregnated with a dielectric liquid. The phase coils are formed into inner and outer layers with each coil layer subdivided into a plurality of sections having series connected turns. Spaces between or within the layers contain dielectric liquid which is circulated for cooling the winding. Intracoil insulation between the coil layers is comprised of laminated sheets of permeable material impregnated with a dielectric liquid. The coil sections are coupled in series in a manner to minimize the maximum voltage differentials between the conductors and adjacent coil sections. In another embodiment the turns of each coil are arranged in adjacent layers separated by intracoil insulation material. The adjacent layers are further subdivided into pairs of sublayers formed of parallel conductors separated by a cooling duct through which a dielectric liquid circulates.

Cooling and insulating system for extra high voltage electrical machine

An electrical rotating machine having winding coils with turns disposed in a pancake configuration which spirals outwardly about the axis of rotation of the machine. The coils are interleaved circumferentially about the axis with uniform and smooth inter-coil spacing for placement of electrical insulation of the type suitable for high voltage applications. The spiral pancake coils when assembled provide a generally cylindrical winding configuration which is conducive to being well-supported by the stator shield.

Cooled spiral winding for electrical rotating machine stator

A dynamoelectric machine having a stator portion with internally cooled windings disposed therein which are electrically and hydraulically connected to a system of conduits each of which conducts both electricity and coolant. The system of conduits provides electrical and coolant communication to the terminating portions of the windings and supplies coolant to intermediate end turn portions of the windings. Each conduit branches at one end into several members, one of which becomes a phase lead when electrically connected to a terminating portion of a winding while the remaining members conduct coolant in an electrically insulated manner to the winding's terminating and end turn portions.

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Pittsburgh, PA, United States of America

Carl Flick