Liquid Insulating Medium Patents (Class 336/58)
  • Publication number: 20080197955
    Abstract: An electric apparatus, preferably a transformer, is hermetically sealed and filled with a dielectric liquid. Devices for recording heat-related volume variations of the dielectric liquid are contained in the apparatus. Volume variations are compensated with the aid of a gas cushion, which is thermally uncoupled from the dielectric liquid. The largest part of the gas cushion is arranged in a container separated from the dielectric liquid expansion tank. All the components of volume compensating devices are constructed in such a way that the operation of used monitoring devices, in particular, also the protection against Buchholz relais waves is maintained. The invention makes it possible to hermetically seal the transformer, thereby substantially reducing the aging of the dielectric liquid and the cellulose-based insulating material of the apparatus. Furthermore, the inventive device makes it possible to avoid the use of air-dehumidifiers and respective conduits.
    Type: Application
    Filed: July 14, 2006
    Publication date: August 21, 2008
    Applicant: SIEMENS AKTIENGESELLSCHAFT
    Inventor: Jorg Findeisen
  • Patent number: 7330096
    Abstract: A fault current limiter (FCL) comprises: an air core flat clock spiral inductor comprising wound electrically conductive material and insulated turns; and two terminations configured for attaching the spiral inductor in series with a power carrying conductor.
    Type: Grant
    Filed: November 2, 2004
    Date of Patent: February 12, 2008
    Assignee: General Electric Company
    Inventors: Manoj Ramprasad Shah, William James Premerlani, Patricia Chapman Irwin, Guanzhong Gao, Nancy Ellen Frost, Karen Broadwell Lausier
  • Patent number: 7317598
    Abstract: A device for preventing the explosion of an electric transformer equipped with a tank filled with combustible coolant fluid, includes a pressure relief element to decompress the tank, a reservoir arranged downstream of the pressure relief element and at least one stopper valve on the reservoir such that the reservoir is hermetic in order to collect a fluid that passes through the pressure relief element.
    Type: Grant
    Filed: June 22, 2006
    Date of Patent: January 8, 2008
  • Patent number: 7205874
    Abstract: The invention deals with increasing the quality of insulating mineral oil in transformers, by providing an isolating layer of flowing nitrogen over the oil's surface to keep ambient air from combining or absorbing with or in the oil, also providing a kidney or filter to remove undesirable contaminants such as water, oxygen, free radicals and debris from the oil, and providing a means of sensing trace gases produced in the oil responsive to transformer conditions and mixed with nitrogen flow to diagnose transformer conditions of interest such as hot-spots, short circuits, insulation failure or similar indicators of failure or incipient failure or need for service, the trace gas analysis being capable of remote monitoring and interpretation. The invention has application in the field of transformers where it is useful to provide self-sufficient and environmentally equipment and methods to prolong service life and reliability between service or inspection of medium, high, and extra-high voltage power.
    Type: Grant
    Filed: May 22, 2006
    Date of Patent: April 17, 2007
    Assignee: InSoil Canada Ltd.
    Inventor: Ioan A. Sabau
  • Patent number: 7205875
    Abstract: An inductor includes an elongate magnetic core, a coil wrapped around the core and a spacer that separates the coil from the core to provide a coolant passage between the coil and the core. The coolant passage may include an air passage that extends substantially parallel to an axis of the core and that has first and second openings proximate respective first and second ends of the core. The coil may include a twisted bundle of individually insulated conductors. The inductor may be housed in a flux-tolerant compartment, i.e., a conductive aluminum structure that supports eddy currents with relatively acceptable resistive losses.
    Type: Grant
    Filed: May 14, 2004
    Date of Patent: April 17, 2007
    Assignee: Eaton Power Quality Corporation
    Inventors: George W. Oughton, Jr., Lei Winston Zeng, Larry Van Lynam
  • Patent number: 7049922
    Abstract: The invention deals with increasing the quality of insulating mineral oil in transformers, by providing an isolating layer of flowing nitrogen over the oil's surface to keep ambient air from combining or absorbing with or in the oil, also providing a kidney or filter to remove undesirable contaminants such as water, oxygen, free radicals and debris from the oil, and providing a means of sensing trace gases produced in the oil responsive to transformer conditions and mixed with nitrogen flow to diagnose transformer conditions of interest such as hot-spots, short circuits, insulation failure or similar indicators of failure or incipient failure or need for service, the trace gas analysis being capable of remote monitoring and interpretation. The invention has application in the field of transformers where it is useful to provide self-sufficient and environmentally equipment and methods to prolong service life and reliability between service or inspection of medium, high, and extra-high voltage power.
    Type: Grant
    Filed: December 5, 2002
    Date of Patent: May 23, 2006
    Assignee: Insoil Canada Ltd.
    Inventor: Ioan A. Sabau
  • Patent number: 6985061
    Abstract: An arrangement and a method for use in installation procedures for subsea transformers. A central, hole or tube is included in an encapsulation enclosing a transformer that is to be installed. Three core elements of the transformer are arranged symmetrically around the hole or tube forming a triangle or a delta. The transformer is lowered towards a a foundation placed on the sea floor wherein a guide pin is mounted. When the transformer has found its way to the foundation, the guide pin will enter the tube, and the transformer will slide down onto the guide line pin. The tube is terminated by a funnel shaped opening, thus making it easier not to miss the guide pin by the tube opening. The transformer is horizontally oriented by means of orientation keys localized within the tube.
    Type: Grant
    Filed: July 2, 2001
    Date of Patent: January 10, 2006
    Assignee: Vetco Aibel AS
    Inventors: Gunnar Hafskjold, Nils Arne Soelvik
  • Patent number: 6914195
    Abstract: An oil-filled pole-mounted distribution transformer comprises a tank housing a transformer core-coil assembly immersed in cooling oil. The tank is made of a corrosion-proof composite material and a radiator is provided for cooling the oil. The radiator is external to the tank and has a hot oil inlet and a cool oil outlet located at different levels into the tank for causing a natural circulation of oil through the radiator by thermal siphoning.
    Type: Grant
    Filed: April 30, 2003
    Date of Patent: July 5, 2005
    Assignee: VA Tech Transformateurs Ferranti-Packard (Quebec) Inc.
    Inventors: Marc-Antoine Archambault, Bernard Lefebvre, Viet Pham, Daniel Bastarache, Christian Fournelle, René Laprise, Guy Morissette
  • Patent number: 6909349
    Abstract: A system (27) for reducing the temperature of cooling oil for a power transformer (12) includes a heat exchanger (44) interposed in the cooling oil system. The heat exchanger (44) relies upon a liquid-to-liquid exchange of heat from the heated oil to a coolant flowing through the heat exchanger. In one embodiment, the coolant provided to the heat exchanger is obtained from an absorption chiller (65). Heat energy is provided to the chiller (65) from a heat storage device (80). In a specific embodiment, the heat storage source (80) can be a phase change material device. In a preferred cooling system, a programmable controller (55) determines the activation and operation of the system. The controller (55) can sense transformer or cooling oil temperature to trigger activation. In a preferred embodiment, the controller (55) compares a current temperature history against a temperature profile to anticipate increased cooling requirements.
    Type: Grant
    Filed: November 17, 2000
    Date of Patent: June 21, 2005
    Assignee: Trexco, LLC
    Inventors: Robert L. Longardner, Anthony M. Visnesky, Jr.
  • Patent number: 6905638
    Abstract: In one aspect, the present invention provides a dielectric fluid for use in electrical equipment comprising a vegetable oil or vegetable oil blend. In another aspect the invention provides devices for generating and distributing electrical energy that incorporate a dielectric fluid comprising a vegetable oil or vegetable oil blend. Methods of retrofilling electrical equipment with vegetable oil based dielectric fluids also are provided.
    Type: Grant
    Filed: July 15, 2003
    Date of Patent: June 14, 2005
    Assignee: Cooper Industries, Inc.
    Inventors: Jerry L. Corkran, C. Patrick McShane, Kevin J. Rapp, Gary A. Gauger, Richard A. Harthun
  • Patent number: 6873236
    Abstract: A fault current limiter (FCL) comprises: an air core flat clock spiral inductor comprising wound electrically conductive material and insulated turns; and two terminations configured for attaching the spiral inductor in series with a power carrying conductor.
    Type: Grant
    Filed: October 24, 2001
    Date of Patent: March 29, 2005
    Assignee: General Electric Company
    Inventors: Manoj Ramprasad Shah, William James Premerlani, Patricia Chapman Irwin, Guanzhong Gao, Nancy Ellen Frost, Karen Broadwell Lausier
  • Patent number: 6838968
    Abstract: In order to cool the windings, core and optionally the wall of the element (1) receiving the windings (3,4) and the core (2) as effectively as possible, conducting surfaces (5, 6, 8,15) are disposed inside said element in such a way that the flow of coolant initially passes along the windings (3,4), followed by the limbs (21,22) of the core surrounded by the windings, and subsequently the other areas (23, 24, 1). Said arrangement of conducting surfaces is particularly suitable for use with transformers having superconductive windings made of HTSL conductor material.
    Type: Grant
    Filed: October 2, 2003
    Date of Patent: January 4, 2005
    Assignee: Siemens Aktiengesellschaft
    Inventors: Wolfgang Nick, Reinhard Schlosser, Heinz Schmidt, Peter van Hasselt
  • Patent number: 6709496
    Abstract: An air demoisturizer for an oil expansion vessel of an electrical power unit like an oil-filled transformer, tap changer or choke, has a heating element in the body of absorbent and utilizes a heat-regeneratable absorbent which is cut off by a moisture detector from the oil expansion vessel when the absorbent is saturated and is thermally regenerated. The demoisturizing column is provided in line with an oil receiver through which the dry air is passed before reaching the oil expansion vessel.
    Type: Grant
    Filed: November 13, 2002
    Date of Patent: March 23, 2004
    Assignee: Messko Albert Hauser GmbH & Co. KG
    Inventors: Karsten Viereck, Rainer Brill, Kurt Kugler, Werner Krüger
  • Patent number: 6661322
    Abstract: A sound-insulating device for a stationary induction machine with an active part, an insulating fluid surrounding the active part, and a tank enclosing the insulating fluid. The sound-absorbing device includes a gas-filled cavity and a resilient member surrounding the gas-filled cavity, thus obtaining a sound-insulating device that is extremely compressible. In the induction machine, the device is arranged between the active part and the tank of the induction machine and is spaced from the inside of the tank. The sound-insulating device preferably has an extent in one plane, whereby the device has a membrane portion facing the active part and a membrane portion facing the tank. Preferably, at least one of the membrane portions has at least one corrugated region, and a spacing membrane is arranged in the cavity making contact with the membrane portion at at least two points.
    Type: Grant
    Filed: March 22, 2002
    Date of Patent: December 9, 2003
    Assignee: ABB T & D Technology Ltd.
    Inventor: Jan Anger
  • Publication number: 20030197583
    Abstract: Disclosed are a method and a device for cooling a high voltage transformer for a microwave oven, in which the high voltage transformer is sealed so as to separate a coil and a core from the outside and to improve a cooling effect, and in which electric connection lines leading from the high voltage transformer are effectively treated and a fixed structure of a container for accommodating the high voltage transformer is improved so as to protect users of the high voltage transformer from dangers such as an electrical shock occurring in inspecting the microwave oven, thereby improving performance and quality of the microwave oven and the high voltage transformer.
    Type: Application
    Filed: April 18, 2003
    Publication date: October 23, 2003
    Inventor: Bu-Sik Choi
  • Patent number: 6613250
    Abstract: In one aspect, the present invention provides a dielectric fluid for use in electrical equipment comprising a vegetable oil or vegetable oil blend. In another aspect the invention provides devices for generating and distributing electrical energy that incorporate a dielectric fluid comprising a vegetable oil or vegetable oil blend. Methods of retrofilling electrical equipment with vegetable oil based dielectric fluids also are provided.
    Type: Grant
    Filed: April 4, 2002
    Date of Patent: September 2, 2003
    Assignee: Cooper Industries, Inc.
    Inventors: C. Patrick McShane, Jerry L. Corkran, Richard A. Harthun, Gary A. Gauger, Kevin J. Rapp
  • Publication number: 20030155999
    Abstract: A reactor comprising a reacting vessel 31 that contains a fluid including high temperature and high pressure water under target reaction temperature and reaction pressure condition and performs a reaction treatment to a reactant by the fluid, a first pipe 25 connected to the reacting vessel 31 to supply the reactant to the reacting vessel 31, and a first partition means 50 for partitioning between first pipe 25 and the reacting vessel 31 so as to prevent a leakage of any one of the fluid, the reactant, and a reaction product from the reacting vessel 31 side to the first pipe 25 side. The first partition means 50 is comprised of for example a valve 51, a shaft 52, a weight 53, a supporting member 54, and a pipe 55, and normally, due to the weight 53, the valve 51 closes an opening of a bottom end of the pipe 55. That is, it isolates the pipe 55 and the inside of the reacting vessel 31.
    Type: Application
    Filed: April 8, 2003
    Publication date: August 21, 2003
    Inventors: Noritaka Sato, Tsutomu Noguchi
  • Patent number: 6563410
    Abstract: A small footprint power transformer constructed so as to exhibit improved heat dissipation characteristics and an enhanced flow of a cooling medium. The transformer construction achieves small footprint by superimposing the core legs with the windings in vertical relationship. Highly heat conductive plane dissipators are inserted between adjacent finished coil discs and extended beyond the winding structure, terminating in fins arranged to assure maximum heat transfer to a cooling medium flowing therepast resulting in substantial reduction of the temperature rise.
    Type: Grant
    Filed: November 16, 2000
    Date of Patent: May 13, 2003
    Inventor: Louis L. Marton
  • Patent number: 6549110
    Abstract: A compensating device suitable for use in railway car transformers has at least one compensation receptacle in fluid communication connection with the interior of the housing of a transformer and having a fluid volume. A separating element limits the fluid volume in the compensation receptacle. When a change occurs in the fluid volume in the compensation receptacle, the separating element is subject to a change in position. The separating element is designed in the form of a roll-over membrane. The circumferential edge of the membrane is connected to the side walls of the compensation receptacle at a distance form the bottom of the receptacle in a sealing manner. The connection is such that the roll-over membrane, in its rolled-up state, has a position in which it allows for the largest amount of fluid volume by substantially extending in one plane at a distance form the bottom.
    Type: Grant
    Filed: March 29, 2001
    Date of Patent: April 15, 2003
    Assignee: Hydac Technology GmbH
    Inventor: Herbert Baltes
  • Patent number: 6529108
    Abstract: In an electric apparatus, insulating cylinders having different diameters are arranged in a shape of multiple cylinders between the iron core and the low voltage winding, between the low voltage winding and the high voltage winding and on the periphery of the high voltage winding. Spacers are separately arranged between layers of the plurality of insulating cylinders to form a plurality of insulating medium paths. A flow stopping member for stopping the flow of the insulating medium in the insulating medium paths which is made of an insulating material with a low density is arranged at at least one of the upper and lower ends of each of the insulating medium paths.
    Type: Grant
    Filed: June 6, 2001
    Date of Patent: March 4, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Keiichi Ito, Kiyoyuki Ishikawa, Yasuji Yoshizumi
  • Patent number: 6522229
    Abstract: The invention relates to a transformer tank generally shaped like a rectangular prism and filled with insulating liquid and assembled mainly by welding. The tank comprises a detachably fastened transformer cover plate and a transformer core placed in the transformer tank while the cover plate is detached. In accordance with the invention, at least one of the substantially vertical walls of the transformer tank comprises a detachable wall portion whose detachment allows the transformer core to be removed from the transformer tank through an opening formed by the detachment of the wall portion. In this way the transformer can be repaired on site without having to lift the transformer core from the transformer tank in the conventional manner, which would require free space above the transformer.
    Type: Grant
    Filed: October 3, 2001
    Date of Patent: February 18, 2003
    Assignee: ABB Technology AG
    Inventors: Sakari Laine, Kari Seppänen, Timo Rintamäki
  • Patent number: 6456179
    Abstract: A container (2) with an oil immersed core (1) and windings has corrugated walls. Bushing insulators (9,10) have pressure-resistant and water-resistant cable shoes (11). A tank encompasses another container (4) filled with insulating oil (3) and has pressure-resistant cable bushing (13) and connectors for electrical connections of the transformer.
    Type: Grant
    Filed: December 22, 2000
    Date of Patent: September 24, 2002
    Assignee: Merger Recipient ABB Oy
    Inventors: Johan Backa, Karl Engman, Torvald Haldin, Esa Virtanen
  • Patent number: 6398986
    Abstract: In one aspect, the present invention provides a dielectric fluid for use in electrical equipment comprising a vegetable oil or vegetable oil blend. In another aspect the invention provides devices for generating and distributing electrical energy that incorporate a dielectric fluid comprising a vegetable oil or vegetable oil blend. Methods of retrofilling electrical equipment with vegetable oil based dielectric fluids also are provided.
    Type: Grant
    Filed: April 9, 1999
    Date of Patent: June 4, 2002
    Assignee: Cooper Industries, Inc
    Inventors: C. Patrick McShane, Jerry L. Corkran, Richard A. Harthun, Gary A. Gauger, Kevin J. Rapp
  • Patent number: 6384703
    Abstract: A sealed transformer for use in charging the batteries of an electric automobile includes a housing that contains the secondary windings, a core and a dielectric fluid. A removable primary winding coupler is inserted into the housing to complete a magnetic circuit. During operation of the magnetic circuit, heat is continuously generated by the primary and secondary windings and the core. The fluid undergoes a first phase change and boils as it absorbs the generated heat. The boiling fluid absorbs additional heat and undergoes a second phase change is it turns into a vapor. The heat of vaporization is released into thin windows formed in the transformer housing when the vapors contact the relatively cooler windows and re-condense into a liquid. A continuous cycle of boiling, vaporizing, and condensing occurs during operation of the transformer to cool the transformer and to improve the power density of the transformer.
    Type: Grant
    Filed: December 11, 2000
    Date of Patent: May 7, 2002
    Assignee: General Motors Corporation
    Inventors: Sergio Ramos, Victor O. Asbury
  • Patent number: 6217634
    Abstract: The present invention monitors and removes contaminants from dielectric fluids by utilizing an apparatus having a chamber and tube configuration. The chamber encloses a plurality of tubes which include porous hollow fibers with an inert polymer coating. Conduits route the dielectric fluid to and from operative equipment. An atmosphere control device creates an atmospheric condition within the chamber that causes contaminants within the dielectric fluid to migrate through the tubes into the chamber, thereby producing refined dielectric fluid. The method of the present invention removes contaminants from a dielectric fluid. The dielectric fluid is routed from operative equipment and passes through tubes enclosed within a chamber. An atmospheric condition is created within the chamber to cause contaminants within the dielectric fluid to migrate into the chamber. A refined dielectric fluid is produced which is directed back to the operative equipment.
    Type: Grant
    Filed: August 27, 1999
    Date of Patent: April 17, 2001
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Nicola Dominelli, David R. Pugh, Gordon R. Ashby, David Casson
  • Patent number: 6185099
    Abstract: Electronic power system is connected at an input to an electrical supply cable (24) and at an outlet to a conductive cable (17) connected to a system of current transmission, the whole of the device being adapted to be buried in the ground in a concrete box (1) such that the current transmission system will be able to transmit a current to an electrical machine such as an automobile that parks above it to receive a battery charge. A sealed metallic receptacle (2) in the form of a box filled with heat transfer liquid, is provided, a sealed compartment being located below the bottom (2a) of the latter box, in which is disposed the electronic power system of which at least one electronic power component is directly fixed to the lower surface of the bottom of the latter box, so as to give rise within the receptacle to stirring of the heat transfer liquid by thermosiphon effect.
    Type: Grant
    Filed: April 2, 1999
    Date of Patent: February 6, 2001
    Inventor: Claude Le Gal
  • Patent number: 6157282
    Abstract: This invention relates to a cooling system for a transformer. A winding defining a coil, including a duct having an open top and bottom, is sealed to a sleeve, thus forming a closed circulatory path. A fluid is retained and circulated within the circulatory path.
    Type: Grant
    Filed: December 29, 1998
    Date of Patent: December 5, 2000
    Assignee: Square D Company
    Inventor: Philip J. Hopkinson
  • Patent number: 6052060
    Abstract: Insulating oil in electric power transmission switchgear such as a load tap changer for a transformer is filtered for removal of accumulated water and carbon particles. The filter and associated circulation pump is usually located in a separate cabinet external to the switchgear with circulation conduits connecting the filter, the pump and the switchgear reservoir. To prevent or minimize equipment damage that is presaged by excessive insulating oil temperature, oil flow within the oil circulation conduits is monitored for temperature excesses. Alarms are issued and electrical loads are disconnected upon detection of an excess temperature event. If desired, provision may be made for disconnected the jeopardized equipment from its respective service load.
    Type: Grant
    Filed: March 9, 1998
    Date of Patent: April 18, 2000
    Assignee: Filmax, Inc.
    Inventors: David McMahan Butler, Johnny James Clark
  • Patent number: 5912215
    Abstract: A food grade, biodegradable dielectric composition and method for preparation thereof, comprising an unsaturated hydrocarbon alone, or in a blend with a food grade natural or synthetic hydrocarbon, which has been processed to remove polar contaminants and further including an antioxidant additive is disclosed.
    Type: Grant
    Filed: October 16, 1997
    Date of Patent: June 15, 1999
    Assignee: Electric Fluids, LLC.
    Inventors: Richard Sapienza, Robert Silverstein
  • Patent number: 5778863
    Abstract: To provide an ignition coil for an internal combustion engine which improves high-voltage sealing performance and moreover reduces housing outer diameter, an ignition coil for an internal combustion engine is made up of a transformer portion of cylindrical configuration housed within a housing chamber of a case, a control-circuit portion which is positioned on one end portion of this transformer portion and causes primary current of the transformer portion to be intermittent, and a connecting portion which is positioned on another end portion of the transformer portion and supplies secondary voltage of the transformer portion to a spark plug. The interior of the housing chamber is filled with insulating oil which has a flash point of 180.degree. C. or more, a total acid number of oxidation stability of 0.6 mgKOH/g or less, a pour point of -20.degree. C. or less with no cloudiness occurring before that temperature is reached, and a kinematic viscosity of not less than 20 cSt and not more than 180 cSt at 40.
    Type: Grant
    Filed: December 5, 1995
    Date of Patent: July 14, 1998
    Assignee: Nipponenso Co., Ltd.
    Inventors: Kazutoyo Oosuka, Masami Kojima, Shozo Ikezima
  • Patent number: 5736915
    Abstract: An electrical apparatus, such as a transformer, includes an expandable internal chamber that is nonventing and completely and permanently sealed from the ambient environment. The chamber houses a core and coil assembly or other current-carrying conductor and is completely filled with dielectric fluid having a pressure less than one atmosphere. The enclosure walls are flexible and are permitted to bow inwardly and outwardly as the volume of the dielectric fluid changes due to thermal expansion and contraction. A method of processing the dielectric fluid and filling and sealing the transformer at sub-atmospheric pressure is also disclosed.
    Type: Grant
    Filed: December 21, 1995
    Date of Patent: April 7, 1998
    Assignee: Cooper Industries, Inc.
    Inventors: Gary L. Goedde, Gary A. Gauger, John Lapp, James Vernon White, Alan Paul Yerges
  • Patent number: 5462685
    Abstract: A convection-cooled electromagnetic device, such as a transformer, and methods of cooling that utilize a ferrofluid as a cooling medium. The device's leakage magnetic field, which can be augmented by auxiliary magnets, draws the ferrofluid toward the device. As the fluid approaches the device its temperature rises, resulting in loss of magnetic properties and a decrease in density. The ferrofluid rises as its temperature approaches the Curie point, since the gravitational effect of density reduction begins to overcome the weakening magnetic attraction. Movement of hot ferrofluid is strongly assisted by the attraction exerted by the device on cooler, more intensely magnetic ferrofluid, which displaces the hot ferrofluid. The displaced ferrofluid cools as a result of movement from the heat source and through contact with the walls of the housing. Preferably, the Curie temperature of the ferrofluid is close to or slightly higher than the operating temperature of the device.
    Type: Grant
    Filed: December 14, 1993
    Date of Patent: October 31, 1995
    Assignee: Ferrofluidics Corporation
    Inventors: Kuldip Raj, Ronald Moskowitz
  • Patent number: 5341083
    Abstract: A contactless recharging system and method for recharging a battery storage device onboard an electric vehicle has a primary converter station for converting power from a power source into high frequency power at a selected charging rate. The vehicle has a secondary converter for converting high frequency power into DC power to charge the battery. The converters are coupled together by a contactless coupling of a conductor loop and a coupling link forming a coaxial winding transformer. The coupled link and loop carry a communication indicating the selected charging rate of the battery. The link has a magnetic core and a core-mounted conductor at least partially surrounded by the core. The core-mounted conductor selectively at least partially surrounds a portion of the loop to transfer power therebetween. The core-mounted conductor is coupled to one of the converters, and the loop is coupled the other converter.
    Type: Grant
    Filed: October 20, 1992
    Date of Patent: August 23, 1994
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Keith W. Klontz, Deepakraj M. Divan, Donald W. Novotny, Robert D. Lorenz
  • Patent number: 5336847
    Abstract: An nonflammable insulating liquid is obtained by adding an emulsifying agent having a volume ratio of 1 to 3% to an insulating liquid containing a fluorocarbon liquid of at least 25% in a volume ratio to cause emulsification. In this liquid mixture, when polyol ester or dimethylcyloxane is used as the insulating liquid, an nonflammable insulating liquid that does not cause pollution or an environmental problem can be obtained. When tricresyl phosphate is used as the insulating liquid, an nonflammable insulating liquid having a dielectric constant close to that of insulating paper can be obtained. A liquid pipe for circulating a fluorocarbon emulsion in a tank is provided outside the tank, and a pump and a stirrer are connected midway along the liquid pipe to constantly stir the fluorocarbon emulsion, thereby preventing it from being separated into two layers. When a radiator is provided to the liquid pipe, the stirring system for the fluorocarbon emulsion can also serve as the cooling system.
    Type: Grant
    Filed: April 30, 1992
    Date of Patent: August 9, 1994
    Assignee: Fuji Electric Co., Ltd.
    Inventor: Yoshitake Nakagami
  • Patent number: 5324886
    Abstract: An insulting-liquid immersed electrical machine comprises an electrical machine, a hermetically sealed tank containing the electrical machine, and insulating liquid arranged between the electrical machine and the tank, wherein the tank includes a deformable member through which gas and liquid cannot pass and whose shape is variable so that a receiving volume capable of receiving the insulating liquid between the tank and the electrical machine is variable. The insulating liquid completely fills the receiving volume in the tank, and a pressurizing arrangement is provided for adjusting the shape of the deformable member so that the pressure of the insulating liquid in the tank is kept at a suitable degree for preventing the insulating liquid from vaporizing.
    Type: Grant
    Filed: January 28, 1992
    Date of Patent: June 28, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Ryoji Nakatake, Yoshito Uwano, Takeshi Sakamoto
  • Patent number: 5250750
    Abstract: Heat transfer, lubricating, functional and/or insulating fluid compositions for use in apparatus such as electrical transformers contain up to 25 weight percent of one or more oil additives and a 1-octene and/or 1-decene dimer and/or a 1-octene and 1-decene co-dimer oil having improved low temperature properties which oil contains less than about 2.5 weight percent of, respectively, the 7-methylpentadecene, 9-methylnonadecene and, 7- and 9-methylheptadecene isomers. The dimers can be hydrogenated to provide the saturated counterparts of the isomers.
    Type: Grant
    Filed: September 8, 1992
    Date of Patent: October 5, 1993
    Assignee: Ethyl Corporation
    Inventors: Ronald L. Shubkin, Kevin J. Theriot
  • Patent number: 5047744
    Abstract: A transformer of the type used to produce high voltage for an electrostatic field apparatus has a hermetically sealed container. The container encloses a coil assembly having primary and secondary coils wound on a common core. Electrical terminals extend outward from the container and are connected to the coils. The interior volume of the container is completely filled with a thermally conductive, electrically non-conducting fluid. The internal pressure of the transformer is less than one atmosphere at 22.degree. C. The transformer can be operated in any mounting orientation of its rated power. A method of manufacturing the transformer is described by which gases are removed from the container so that it can be completely filled with the fluid.
    Type: Grant
    Filed: January 23, 1990
    Date of Patent: September 10, 1991
    Assignee: Plasma Technics, Inc.
    Inventors: Ralph M. Francis, Jr., John C. Mastopietro
  • Patent number: 4950837
    Abstract: The present invention is directed to a method for reducing PCB concentration in an electrical induction apparatus containing a dielectric fluid with greater than 500 ppm PCB to a level of less than about 50 ppm PCB. Dielectric fluid containing greater than 500 ppm PCB is drained from an electrical induction apparatus, and the drained apparatus then is filled with tetrachloroethylene as a first interim dielectric fluid. The apparatus is then electrically operated with the first interim dielectric fluid so as to attain about an equilibrium PCB concentration in the first fluid. The first interim dielectric fluid then is drained from the apparatus and replaced with fresh tetrachloroethylene as a second interim dielectric fluid. The apparatus then is electrically operated with the second interim dielectric fluid so as to attain about an equilibrium PCB concentration in the second fluid.
    Type: Grant
    Filed: July 18, 1989
    Date of Patent: August 21, 1990
    Assignee: General Electric Company
    Inventors: Craig W. Horneck, John B. McDermott, Daniel P. Smith, Shiro G. Kimura, Roger A. Shisler
  • Patent number: 4904972
    Abstract: A gas-insulated stationary induction electrical apparatus comprising a first closed vessel sealingly accommodating therein a main body having an iron core formed by laminating silicon steel sheets and also having at least one set of windings each consisting of a high-voltage winding and a low-voltage winding which are disposed apart from the iron core on both sides thereof, and a liquid medium for effecting cooling and insulation; a second closed vessel formed of an insulating material and sealingly accommodating therein the first closed vessel; and an insulating gas under a predetermined pressure which is sealed within the gap between the first and second vessels, wherein the induction apparatus main body is submerged in the liquid medium.
    Type: Grant
    Filed: June 28, 1989
    Date of Patent: February 27, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Etsunori Mori, Tadashi Kiuchi, Kiyoto Hiraishi, Masaru Watanabe
  • Patent number: 4843187
    Abstract: A gasket assembly including a base having a central opening and a circular slot having an undercut portion extending around the central opening, a circular gasket positioned in the circular slot and having a tapered side located proximate the undercut portion, and cementitious sealant material abutting the tapered side of the gasket and in the undercut portion for retaining the gasket in the slot. The gasket assembly is especially useful for the seal for the pressure relief valve of an electrical power transformer.
    Type: Grant
    Filed: February 5, 1988
    Date of Patent: June 27, 1989
    Assignee: Qualitrol Corporation
    Inventor: Wendell D. Johnson
  • Patent number: 4794982
    Abstract: A cast iron or steel heat transfer member is used in network protectors to provide optimum cooling while avoiding prior corrosion problems.
    Type: Grant
    Filed: December 28, 1987
    Date of Patent: January 3, 1989
    Assignee: Westinghouse Canada Inc.
    Inventor: Archibald Corkigian
  • Patent number: 4763093
    Abstract: A high-power pulse transformer for short, high-voltage and/or high-current pulses includes:a base plate in a container, an insulating, cooling dielectric liquid with a given heat transfer coefficient in the container;at least one magnet core on the base plate with self-enclosed magnet legs around a central window and wide sides with axes normal to the axis of the window;at least an undervoltage and an overvoltage winding in the liquid wrapped in each other around parts of the magnet core immersed in the liquid and linked to the magnet core and to each other, the windings including turns of substantially mutually doubly-wound electrically insulated metallic conductors having winding ends disposed in leadthroughs in the container walls, the conductors having surfaces with a heat transfer coefficient higher than that of the dielectric liquid;the turns of each winding being self-supported and spaced apart from the turns of the other winding by a first minimum spacing and spaced from the magnet core by a second mi
    Type: Grant
    Filed: August 21, 1986
    Date of Patent: August 9, 1988
    Assignee: Kraftwerk Union Aktiengesellschaft
    Inventors: Hans-Jurgen Cirkel, Willi Bette
  • Patent number: 4745966
    Abstract: A heat exchanger panel suitable for cooling fluid filled electrical apparatus, such as electrical distribution and power transformers, and method of constructing same, which withstands substantially higher pressures without adding significantly to the weight of the heat exchanger. The metallic sheet which is used to construct the heat exchanger panel includes edges which define a substantially rectangular configuration, with predetermined opposite edges therof being folded to increase the edge thickness of the sheet prior to forming the fins. The fins are formed via bend lines which extend from folded edge to folded edge. This provides at least twice the material thickness where the heat exchanger panel is welded to the tank of the associated apparatus, and at least four times the material thickness where the folded fin is welded to form the fin cavity.
    Type: Grant
    Filed: July 22, 1986
    Date of Patent: May 24, 1988
    Assignee: Westinghouse Electric Corp.
    Inventor: Randall N. Avery
  • Patent number: 4745677
    Abstract: An electromagnetic inductor means such as a transformer is improved by reducing the amount of condensable cooling liquid to a level approximating that actually needed to effect cooling; by injecting a resin into spaces between the casing and an insulating container surrounding the sides and bottom of the windings.
    Type: Grant
    Filed: June 6, 1986
    Date of Patent: May 24, 1988
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Masaru Shichi
  • Patent number: 4675637
    Abstract: A superconducting static machine having a magnetic circuit includes a magnetic circuit core at mere ambient temperature and very low (cryogenic) temperature windings (1A, 1B) and one or more magnetic circuit cores at considerably higher temperatures. The magnetic circuit core is disposed in a thermally-insulating chamber (3) which is itself disposed inside a very low temperature (9) containing the windings. The invention is particularly applicable to transformers.
    Type: Grant
    Filed: May 6, 1985
    Date of Patent: June 23, 1987
    Assignee: Alsthom-Atlantique
    Inventors: Alain Fevrier, Jean-Claude Kermarrec, Gerard Bottini
  • Patent number: 4644314
    Abstract: An expansion chamber 23 for a porcelain clad current transformer is formed by a base plate 231 secured on an insulating tube 22 housing a primary coil 21, and a unitary inverted cup-shaped envelope 232 removably mounted on the upper surface of the base plate. Primary terminals 26electrically connected to the coil within the expansion chamber are installed through the base plate to thereby facilitate the necessary connections before the chamber is assembled and filled with insulating oil.
    Type: Grant
    Filed: May 29, 1986
    Date of Patent: February 17, 1987
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takeo Fukatsu
  • Patent number: 4621302
    Abstract: An electrical insulating oil which is suitable for use in impregnating electrical appliances such as capacitors, cables and transformers, especially those in which plastic materials are used partially or totally as dielectrics or insulating materials, and electrical appliances that are impregnated with the above electrical insulating oil. The electrical insulating oil of the invention contains at least one monoolefin and/or diolefin having three condensed or non-condensed aromatic rings.
    Type: Grant
    Filed: March 13, 1985
    Date of Patent: November 4, 1986
    Assignee: Nippon Petrochemicals Company, Limited
    Inventors: Atsushi Sato, Keiji Endo, Shigenobu Kawakami, Hitoshi Yanagishita, Shozo Hayashi
  • Patent number: 4609900
    Abstract: In a high-voltager transformer including a closed casing, a magnetic core with at least one winding, a cooling liquid filling the casing and surrounding the winding, and insulated casing lead-throughs for connecting external lines to the winding, a compensating device forms part of the casing and is exposed to the cooling liquid for permitting expansion of the cooling liquid on being heated, and the cooling liquid is subjected to a pressure greater than that of the ambient air at all operating temperatures of the transformer.
    Type: Grant
    Filed: June 17, 1985
    Date of Patent: September 2, 1986
    Inventors: Bruno Bachhofer, Anton Locher
  • Patent number: 4607245
    Abstract: A gas insulated electromagnetic induction appliance in which a non-condensing insulating gas and a condensing insulating coolant are confined, comprises (a) a pressure detector for detecting a pressure within the container vessel; (b) a gas reservoir connected to the container vessel through a gas discharging passageway including a pipe line, a first gas valve, a compressor, and a gas diffuser; a gas feeding passageway including a pipe line and a second gas valve; and a liquid feeding passageway including a pipe line and a liquid valve; (c) a definite quantity of insulating coolant confined in the gas reservoir; (d) a liquid surface detector for detecting a quantity of the insulating coolant in the gas reservoir; and (e) control means which controls the gas valve, the liquid valve, and the compressor to thereby regulate a pressure in the container vessel and a quantity of the liquid in the gas reservoir.
    Type: Grant
    Filed: February 7, 1985
    Date of Patent: August 19, 1986
    Assignees: Mitsubishi Denki Kabushiki Kaisha, Yutaka Kuroda, Yoshio Yoshida, Yuichi Kabayama
    Inventors: Yutaka Kuroda, Yoshio Yoshida, Yuichi Kabayama, Tsugio Watanabe, Tetsuro Hakata, Takahiro Matsumoto
  • Patent number: 4588972
    Abstract: A transformer has a vertical winding assembly formed of a stack of pancake coils sandwiched between electrically insulating bases each provided on its surface contacted by an associated one of pancake coils with a plurality of cooling grooves extending in spaced relationship along turns of a rectangular electrically conductive wire forming the pancake coil and opening on the upper and lower portions of the base. A liquid refrigerant sprinkled on the winding assembly is arranged to flow through the cooling grooves via the upper open ends and be discharged via the lower open ends.
    Type: Grant
    Filed: December 13, 1984
    Date of Patent: May 13, 1986
    Assignees: Yoshinobu Harumoto, Yoshio Yoshida, Yuichi Kabayama, Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yoshinobu Harumoto, Yoshio Yoshida, Yuichi Kabayama, Hisao Kan, Tetsuro Hakata, Takahiro Matsumoto