Corona-prevention Patents (Class 310/196)
  • Patent number: 4403163
    Abstract: Conductor bar for electric machines operating at high voltage, including at least two subconductor packets being disposed side by side and being formed of mutually insulated subconductors, the subconductors being intertwined in such a manner that each subconductor occupies each possible physical position in at least one location within the conductor bar, an insulating sleeve, a semiconductor layer applied to the insulating sleeve, a further semiconductor layer disposed between the subconductor packets and the insulating sleeve, the conductor bar having a straight portion and narrow sides having a given width, a narrow-side subconductor bar crossing from one subconductor packet to another, the narrow-side subconductor bar being disposed at a given height filling a portion of the given width of the narrow side leaving a remaining width, hardenable cement layers being disposed substantially at the given height flanking the narrow-side conductor bar in vicinity of the crossing and filling the remaining width.
    Type: Grant
    Filed: August 19, 1981
    Date of Patent: September 6, 1983
    Assignee: Brown, Boveri & Cie AG
    Inventors: Rainer Armerding, Rupert Helmling, Waldemar Kopp, Harry Wagner, Peter Ehrt, Emil Boser
  • Patent number: 4388546
    Abstract: Arrangement for controlling the internal potential in generator rods by means of a band consisting of semi-conductive web, which is wound helically about the wiring assembly composed of insulated conductor elements. In order to obtain a possibly uniform potential over the entire rod length, the band is reinforced by electrically conductive threads spaced in longitudinal direction, whereby the electrically conductive threads are d-c coupled at a contact point with each other and with a conductor element.
    Type: Grant
    Filed: January 15, 1982
    Date of Patent: June 14, 1983
    Assignee: Kraftwerk Union Aktiengesellschaft
    Inventor: Wilhelm Schwanzer
  • Patent number: 4347454
    Abstract: The bars or coils of the stator winding of an electric machine are provided, in the region of the slots, with one or more additional wrappings having a larger cross-section than the slot. These wrappings are set in corresponding recesses in the laminated stack, whereby the bars are made secure in the axial direction.
    Type: Grant
    Filed: August 16, 1979
    Date of Patent: August 31, 1982
    Assignee: Siemens Aktiengesellschaft
    Inventors: Klaus Gellert, Gunter Nagel, Franz J. Pollmeier
  • Patent number: 4207482
    Abstract: An insulated electrical member is made, having in combination, an electrical member covered with insulation and a conducting varnish, where an abrasion resistant stress grading system covers at least part of the conducting varnish, the stress grading comprising: (1) a first base layer of resinous paint containing non-linear SiC having a resistivity value of between 2,000 to 4,000 Meg. Ohm/Square, in contact with the conducting varnish, (2) a second overlapping layer of resinous paint containing non-linear SiC having a resistivity value of between 4,000 to 6,000 Meg. Ohm/Square and containing at least one fibrous support, covering the first base layer and (3) an overcoat of an arc and track resistant resinous insulating varnish; where, at the point of overlap of the SiC layers, the thickness ratio of the base SiC layer:overlapping SiC layer is from 1:1 to 1:15.
    Type: Grant
    Filed: November 14, 1978
    Date of Patent: June 10, 1980
    Assignee: Westinghouse Electric Corp.
    Inventors: Charles L. Neumeyer, Herbert E. Pietsch
  • Patent number: 4095627
    Abstract: According to the invention, electrically conductive paths are formed between the coil armor and the core laminations of dynamoelectric machines for inhibiting corona. This is achieved by injecting an uncured, semiconducting, elastomeric material between the coil sides and slot walls through the use of an injector tool inserted between them, and thereafter curing the material. The uncured material has a viscosity which enables it to be forced under pressure into these spaces, and when cured it has a resistance high enough not to form eddy current paths between laminations and yet low enough to conduct charge from the coil armor to the core. It is also capable of retaining its strength, elasticity, conductivity, etc., and remaining in place between the coils and core under vibrations, coolant flow, electric stresses, repeated temperature changes, etc., for the normal operating life of the machine.
    Type: Grant
    Filed: February 10, 1976
    Date of Patent: June 20, 1978
    Assignee: Canadian General Electric Company
    Inventors: Palmer Lonseth, Hubert Gerald Panter, Donald G. Moorby
  • Patent number: 3975653
    Abstract: A creeping discharge and partial discharge-prevention means for a stator coil end of a rotary electric machine is disclosed. It includes an grounding electrode on an insulator of the stator coil end of the rotary electric machine, a first electrical stress grading coated layer on the insulator of the coil end including the end of the grounding electrode, a shield insulator made of insulation material around the first electrical stress grading coated layer including the end of the grounding electrode, a shield electrode electrically connected to the grounding electrode around the shield insulator, and a second electrical stress grading coated layer coated on the shield insulator including the end of the shield electrode.
    Type: Grant
    Filed: March 13, 1975
    Date of Patent: August 17, 1976
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takeshi Kawakami, Tsutomu Tani, Takatoshi Ishikawa, Syoji Hirabayashi