Patents Assigned to Areva T&D SA
  • Publication number: 20070140891
    Abstract: Process for the preparation of a semiconducting ceramic based on doped tin oxide SnO2 by a process of “PADO” (Precursor Alloy Direct Oxidation) type applied to an alloy of tin and of doping metals or by a process of “PADO” type applied to tin, the doping metals being added in the form of oxides to the powder subjected to sintering.
    Type: Application
    Filed: October 3, 2006
    Publication date: June 21, 2007
    Applicant: AREVA T&D SA
    Inventors: Mehrdad Hassanzadeh, Celine Machado-Bailly, Renaud Metz, Ramon Puyane
  • Publication number: 20070111590
    Abstract: An electrical contact member, suitable for electrically interconnecting two conductive members in series, which members can move relative to each other and are part of an electrical apparatus. The electrical contact includes a strength-imparting base layer made of an electrically conductive material, and a coating layer formed from metallic silver and configured to come into contact with the two electrically conductive members. The coating layer has a micro-structure formed by pure silver crystals, with a presence of nodules made of silver and of an additional metallic material formed by at least one additional metal that is different from silver.
    Type: Application
    Filed: December 28, 2004
    Publication date: May 17, 2007
    Applicant: AREVA T&D SA
    Inventors: Jean-Luc Bessede, Pierre Giannini, Oana Visata
  • Patent number: 7208958
    Abstract: A sensor for picking up partial discharges in an electrical equipment tank filled with a dielectric fluid includes an antenna responsive to the electromagnetic waves generated by such partial discharges. In the sensor, the antenna is formed by two electrodes that are separated from each other by a dielectric resonator. With this arrangement, the sensor has improved sensitivity in the UHF range, while being of dimensions that are considerably smaller than dimensions of a conventional antenna for use in the UHF range.
    Type: Grant
    Filed: February 25, 2004
    Date of Patent: April 24, 2007
    Assignee: Areva T&D SA
    Inventor: Kuppuswamy Raja
  • Patent number: 7199324
    Abstract: The invention relates to a hybrid circuit-breaker which, for each pole, comprises a dielectric-gas interrupting chamber (1) which contains a first contact (1A) and a moving second contact (1B) that are disposed longitudinally to a first axis (AA?) and in which the first contact (1A) is connected to a first terminal (3A) of the network, said interrupting chamber (1) being connected in series with a vacuum bottle (2) which contains a fixed contact (2A) and a moving contact (2B) that are disposed longitudinally to a second axis (BB?) and in which the fixed contact (2A) is connected to a second terminal (3B) of the network, actuating means acting via a single control (4) to move said moving contacts between respective open positions and respective closed positions.
    Type: Grant
    Filed: March 25, 2005
    Date of Patent: April 3, 2007
    Assignee: Areva T & D SA
    Inventor: Michel Perret
  • Patent number: 7183774
    Abstract: The invention provides a method of detecting partial discharges in an electrical appliance insulated in a receptacle and a system of diagnosing the state of the appliance using this method. With the help of an UHF antenna placed in the receptacle of the appliance, the method includes analyzing the spectrum (RS1) of the electromagnetic signal picked up by the antenna and of identifying within the spectrum one or more frequencies of interest (B1, B2), for each of which the signal has an amplitude greater than a predetermined threshold value. To identify the frequency/frequencies of interest, the spectrum of the signal received by the antenna is compared with a reference spectrum (RS2).
    Type: Grant
    Filed: June 1, 2004
    Date of Patent: February 27, 2007
    Assignee: Areva T&D SA
    Inventor: Raja Kuppuswamy
  • Patent number: 7161873
    Abstract: A method of detecting and localizing a source of partial discharge in an electrical apparatus placed in an enclosure containing an acoustically-conductive fluid.
    Type: Grant
    Filed: March 25, 2005
    Date of Patent: January 9, 2007
    Assignee: Areva T&D SA
    Inventors: Raja Kuppuswamy, Sebastien Louise, Niemet Nzihou
  • Publication number: 20060259281
    Abstract: This invention relates to a method for detection of the position of a wave front in a signal received by a detector. This method consists of: converting the signal into a digital signal, defining a working group of N successive samples in the digital signal, and possibly processing the samples in the working group, calculating the energy of the signal from the processed samples in the working group, if any, in terms of the root mean square over a sliding window, the window comprising an optimum number Lopt of samples (Lopt is less than N), the position of the wave front corresponding to the position of the sample for which the energy of the signal exceeds a threshold D that depends on the value of the energy of the signal previously at the wave front, for the first time.
    Type: Application
    Filed: March 27, 2006
    Publication date: November 16, 2006
    Applicant: AREVA T&D SA
    Inventors: Raja Kuppuswamy, Philip Moore, IIiana Portugues, Sebastien Louise
  • Patent number: 7102866
    Abstract: A protection system for an electrical power line system of the type comprising radially connected power line sections, wherein a first electrically upstream one of the line sections is connectable to a power source. The protection system comprises at least one relay installed at or near at least the upstream end of each line section to protect that line section, each relay having an associated circuit breaker. The relays are provided with a first set of accelerated overcurrent functions and a second set of under-current/under-voltage functions, the relays being directional and the first and second sets of functions being time graded in reverse to each other.
    Type: Grant
    Filed: May 7, 2003
    Date of Patent: September 5, 2006
    Assignee: Areva T&D SA
    Inventor: Zhiqian Bo
  • Patent number: 7090176
    Abstract: A support for high-voltage or medium-voltage electrical plant comprises four columns placed on a support surface and connected in pairs by crossmember assemblies. The columns are each articulated to rotate about a first horizontal axis at their end resting on the support surface and about a second horizontal axis on a top crossmember at their other end. The first and second axes are parallel. Two opposite crossmember assemblies allow the two columns connected by one or the other of these two assemblies to move in a stable manner in their rotation plane.
    Type: Grant
    Filed: February 17, 2004
    Date of Patent: August 15, 2006
    Assignee: Areva T&D SA
    Inventors: Michel Chavot, Jean Louis Habert
  • Publication number: 20060145705
    Abstract: A sensor for picking up partial discharges in an electrical equipment tank filled with a dielectric fluid includes an antenna responsive to the electromagnetic waves generated by such partial discharges. In the sensor, the antenna is formed by two electrodes that are separated from each other by a dielectric resonator. With this arrangement, the sensor has improved sensitivity in the UHF range, while being of dimensions that are considerably smaller than dimensions of a conventional antenna for use in the UHF range.
    Type: Application
    Filed: February 25, 2004
    Publication date: July 6, 2006
    Applicant: AREVA T&D SA
    Inventor: Kuppuswamy Raja
  • Publication number: 20060091112
    Abstract: A device for the actuation of the movable contacts of a hybrid circuit breaker allows the following time diagram to be implemented: command the opening of the interrupting chamber, offset the opening of the vacuum switch so as to allow the interrupting chamber contacts to separate at a minimum speed and in a way that is synchronous with the separation of the vacuum switch contacts, close the vacuum switch while keeping the interrupting chamber in the open position. Moreover, closing the interrupting chamber does not act upon the contacts of the vacuum switch. The actuation device can be found in a number of embodiments, and allows the vacuum interrupter to be controlled when the circuit breaker is triggered or closed.
    Type: Application
    Filed: October 21, 2005
    Publication date: May 4, 2006
    Applicant: AREVA T&D SA
    Inventors: Andre Neveu, Andre Cimala, Alain Girodet, Mehdi Lebiad, Gwenael Marquezin
  • Publication number: 20060039171
    Abstract: The invention relates to an on-load transformer tap changing system wherein the secondary or primary of a transformer comprises at least one first and one second taps (p1, p2). A main connection circuit (tra-I2) is used for the permanent connection of the first tap (p1) or the second tap (p2) to an output terminal (b2) of the secondary or primary of the transformer. Secondary connection circuits (I1, I3) are each used to connect a tap (p1, p2) temporarily and directly to said output terminal (b2) of the secondary or primary of the transformer. Each of said connection circuits (I1, tra-I2, I3) comprises one or more insulated gate bipolar transistors and the system can be controlled without zero current value transition detection in the secondary winding. Application: Power transformers.
    Type: Application
    Filed: July 19, 2005
    Publication date: February 23, 2006
    Applicant: AREVA T&D SA
    Inventors: Jean-Paul Lavieville, Witold Weber, Mohamed Ryadi, Milan Saravolac
  • Patent number: 6995330
    Abstract: A high for medium voltage gas insulated earthing switch comprises at least one conducting bar in an enclosure, with a corresponding earthing contact and a phase contact fixed to the said bar that will be electrically connected to the earthing contact to earth the said bar. The earthing contact is installed fixed in the enclosure facing the phase contact, leaving a free space (E) between this phase contact and the earthing contact. A switching element is installed free to move in the enclosure between the phase contact and the earthing contact, and comprises firstly a switching contact that short circuits the space left free (E) to electrically connect the earthing contact and the phase contact when the earthing switch is closed, and secondly an at least partly electrically insulating support on which the switching contact is fixed such that the switching contact is electrically isolated from the phase contact and from the earthing contact when the earthing switch is in an open position.
    Type: Grant
    Filed: August 16, 2004
    Date of Patent: February 7, 2006
    Assignee: Areva T & D SA
    Inventor: Carmelo Gimeno
  • Publication number: 20050248430
    Abstract: The current transformer comprises at least two partial circuits (CBn) each comprising a Rogowski type winding (Cn), each of said the partial circuits being made in the form of an angular portion of a complete circuit (CB) which surrounds at least one primary conductor (10, 10A, 10B, 10C) of the transformer over 360°. The winding (Cn) of each partial circuit (CBn) is constituted by a go winding (Cn0) and by a return winding (Cn1) which extend over the angular extent (?n) of the partial circuit (CBn). For each partial circuit (CBn), the go and return windings are electrically connected in series, both having turns wound in the same direction so as to form a single winding (Cn) which presents a pair of adjacent electrical terminations (T1n, T2n) connected to an acquisition system (7, 7?).
    Type: Application
    Filed: May 6, 2005
    Publication date: November 10, 2005
    Applicant: AREVA T&D SA
    Inventors: Jean-Pierre Dupraz, Lionel Lucot, Olivier Chuniaud, Bernard Regnier
  • Publication number: 20050243649
    Abstract: A method of detecting and localizing a source of partial discharge in an electrical apparatus placed in an enclosure containing an acoustically-conductive fluid.
    Type: Application
    Filed: March 25, 2005
    Publication date: November 3, 2005
    Applicant: AREVA T&D SA
    Inventors: Raja Kuppuswamy, Sebastien Louise, Niemet Nzihou
  • Publication number: 20050205726
    Abstract: A support for high-voltage or medium-voltage electrical plant comprises four columns placed on a support surface and connected in pairs by crossmember assemblies. The columns are each articulated to rotate about a first horizontal axis at their end resting on the support surface and about a second horizontal axis on a top crossmember at their other end. The first and second axes are parallel. Two opposite crossmember assemblies allow the two columns connected by one or the other of these two assemblies to move in a stable manner in their rotation plane.
    Type: Application
    Filed: February 17, 2004
    Publication date: September 22, 2005
    Applicant: AREVA T&D SA
    Inventors: Michel Chavot, Jean Habert
  • Patent number: 6917006
    Abstract: An operating mechanism for a rectilinear motion circuit-breaker, for performing an open-close-reopen cycle, and operating on an operating rod of the circuit-breaker and including closing and opening springs. The opening spring operates on the operating rod. The closing spring operates on a crank end whose other end is connected to a shaft fastened to a flywheel and on which is mounted a closing cam cooperating with a roller on the operating rod. A closing pawl retains the closing spring in a compressed position, opening the closing pawl releasing the closing spring to rotate the cam, thereby closing the circuit-breaker and rearming the opening spring. A rearming motor couples to the shaft by a freewheel. A pawl triggers opening retaining the operating rod against force of the opening spring in the closed position of the circuit-breaker and is adapted to receive an opening command.
    Type: Grant
    Filed: February 14, 2003
    Date of Patent: July 12, 2005
    Assignee: Areva T&D SA
    Inventor: Félix Bachofen
  • Publication number: 20050099187
    Abstract: This invention relates to a method of diagnosing one fault on a transformer winding using a Frequency Response Analysis (FRA). This invention is adapted more particularly to power transformers. The method comprises the following steps: measure the impedance of the said winding as a function of the frequency, the said measurement being represented in the form of a first voltage gain k, compare the said impedance measurement with a reference measurement represented in the form of a second voltage gain k?. The method also comprises a step to determine the relative variation of the first resonant frequency exceeding 10 kHz, the said relative variation being obtained by comparing the said first and second gains k and k?.
    Type: Application
    Filed: October 1, 2004
    Publication date: May 12, 2005
    Applicant: AREVA T&D SA
    Inventor: Simon Ryder
  • Publication number: 20040246000
    Abstract: Method for detecting partial discharges and diagnostic system for electrical apparatus.
    Type: Application
    Filed: June 1, 2004
    Publication date: December 9, 2004
    Applicant: AREVA T&D SA
    Inventor: Raja Kuppuswamy