Feeder Protection In Distribution Networks Patents (Class 361/62)
  • Patent number: 6420799
    Abstract: An electrical power supply system for a vehicle is provided, which can eliminate proliferation of adverse effect on other control modules caused within one of a plurality of control modules. This is accomplished by provision of the power supply system comprising: battery 10 for supplying power; power line PL in a loop lay-out; a plurality of control modules BCM 100, VCM 110, FIM 120, DDM 130, RIM 140, CCM 150 and PDM 160 for a plurality of accessory systems, which are connected via said power line PL in loop lay-out, wherein a power control module (PCM) 20 for controlling the engine is connected to the power supply source via another power line 22 different from the power line PL.
    Type: Grant
    Filed: October 21, 1999
    Date of Patent: July 16, 2002
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Shinichi Sakamoto, Tatsuya Yoshida, Mitsuru Koni, Hiroyuki Saito, Kiyoshi Horibe
  • Patent number: 6417582
    Abstract: A safety switching arrangement has at least two break switches (12a, 12b, 12c) which are connected in series to an evaluation unit (11), in which case the evaluation unit (11) initiates a safety signal, in particular an alarm signal and/or disconnection signal, when at least one of the break switches (12a, 12b, 12c) opens, and determines which of the break switches (12a, 12b, 12c) has opened.
    Type: Grant
    Filed: March 10, 2000
    Date of Patent: July 9, 2002
    Assignee: Sick AG
    Inventors: Franz Josef Dold, Jens Niehus
  • Patent number: 6407896
    Abstract: A power system includes a cable connector (120), a cable (110) comprised of a plurality of wires (211, 212, and 213), and a circuit (230, 421, 422, or 500) for sensing a connection for the cable connector. The circuit is located adjacent to the cable connector and is capable of sensing a predetermined connection condition of the connection of the cable connector. Each wire has an end located within the cable connector.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: June 18, 2002
    Assignee: Motorola, Inc.
    Inventors: Charles C. Hill, John H. Kelly, Kevin Loutfy, Naufel Chafic Naufel
  • Patent number: 6407897
    Abstract: A network protector is provided with diagnostics which alert a utility of component problems in detail. Selected measurements are used to assess the condition of various components such as for example, main contact electrical resistance, a blown fuse, the availability of sufficient voltage for charging the springs which close the main contacts and adequate voltage for tripping the contacts open. These abnormal operating conditions are transmitted to a remote station at the utility so that proper maintenance can be efficiently provided.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: June 18, 2002
    Assignee: Eaton Corporation
    Inventors: Robert Yanniello, John R. Moffat, Steven E. Meiners, Joseph C. Engel, Thomas J. Kenny
  • Patent number: 6392856
    Abstract: A voltage recovery system and its method of operation provides voltage protection to a load connected to a distribution network of a utility power system or network by boosting the voltage on a distribution line, during a momentary voltage sag caused by a fault or other contingency. The method includes voltage protection from a voltage recovery system to a load connected to a distribution network of a utility power network. A voltage protection characteristic required by the load is selected. On the basis of electrical characteristics of the voltage recovery system and the distribution network, a determination is made as to whether the voltage recovery system is capable of providing the required first voltage protection characteristic.
    Type: Grant
    Filed: April 24, 2000
    Date of Patent: May 21, 2002
    Assignee: American Superconductor Corporation
    Inventors: Arnold P. Kehrli, Bradley D. Nelson
  • Patent number: 6385022
    Abstract: A protective relay that derives and processes power system data from multiple user-configurable data source points. Data from multiple source points can be combined in the relay as a single source of data useful to perform a wide variety of monitoring and protection tasks. Multiple digital signal processing modules can be used to provide additional processing resources, including the ability to provide protection and revenue-class metering in a single device.
    Type: Grant
    Filed: June 3, 1999
    Date of Patent: May 7, 2002
    Assignee: General Electric Company
    Inventors: Ara Kulidjian, Jeff Mazereeuw
  • Patent number: 6373669
    Abstract: In switchgear with superordinate power circuit-breakers and a plurality of subordinate power circuit-breakers, the superordinate power circuit-breaker must be triggered in the event of failure of the subordinate power circuit-breakers. This is accomplished as follows: electrical post-arc currents are detected after current zero, the electrical post-arc currents are compared with a predetermined limit value, and if the limit value is exceeded, a signal is effected for triggering the superordinate power circuit-breaker in the switchgear. This method can advantageously be implemented in particular in the case of vacuum circuit-breakers with at least one vacuum interrupter. The associated arrangement has a device which monitors the subordinate power circuit-breakers and, if appropriate, triggers the superordinate power circuit-breaker.
    Type: Grant
    Filed: February 15, 2000
    Date of Patent: April 16, 2002
    Assignee: Siemens Aktiengesellschaft
    Inventors: Werner Hartmann, Wilfried Haas, Jörg Kieser, Harald Kurzmann
  • Patent number: 6369995
    Abstract: A protection relay device for distribution equipment is provided with breakers respectively disposed at branches of a distribution system having the branches in a hierarchical structure, relays respectively disposed at the branches and detecting a short-circuit failure in a lower-rank section and outputting a detection signal, and a central control device receiving the detection signals output by the relays, determining a short-circuit failure section where a short-circuit failure has occurred from the detection signal received, and operating the relay of the branch corresponding to the short-circuit failure section to open the breaker corresponding to the relay.
    Type: Grant
    Filed: December 29, 1999
    Date of Patent: April 9, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kazuhiko Kagawa, Eiji Moritoh
  • Patent number: 6342995
    Abstract: A lighted escutcheon plate for power distribution equipment includes an escutcheon plate in electrical communication with a power distribution circuit; and a plurality of LED bulbs, generally green or alternatively red, mounted on the escutcheon plate, so as to provide a visual indication of an open circuit status by lighting when the power distribution circuit is opened. The plate also includes a plurality of LED bulbs, generally red or alternatively green, mounted on the escutcheon plate, so as to provide a visual indication of a close circuit status by lighting when the power distribution circuit is closed. For tripped circuit conditions the plate includes a plurality of LED bulbs, generally yellow or amber, mounted on the escutcheon plate, so as to provide a visual indication of a trip circuit status by lighting when the power distribution circuit is tripped.
    Type: Grant
    Filed: March 2, 2000
    Date of Patent: January 29, 2002
    Assignee: Instrument Transformers, Inc.
    Inventor: Kent Jones
  • Patent number: 6341055
    Abstract: A differential relay for protecting a power apparatus portion of a power system, such as a bus line, includes incoming and outgoing power lines on which incoming and outgoing currents are present. The incoming and outgoing currents of each phase are applied through current transformers and then through filtering and normalizing circuits prior to application to the differential relay. The differential relay includes a circuit for determining the presence of an external fault, and maintains security by avoiding a tripping action of the relay for said external faults.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: January 22, 2002
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventor: Armando Guzman-Casillas
  • Patent number: 6341054
    Abstract: A control system is used in an intelligent power distribution network. The power distribution network includes multiple branches, each of which is connected to a power source, electrical devices connected to the branches, and a normally-open device connected between two or more branches. The control system includes control elements, each control elements being associated with an electrical device connected to a branch of the distribution network. The control system also includes a master control element associated with the normally-open device. The master control element communicates with the control elements and, when a fault occurs on the distribution network, prevents the normally-open device from closing when information from the control elements indicate that conditions potentially disruptive to the distribution network would occur if the normally-open device were closed.
    Type: Grant
    Filed: December 10, 1999
    Date of Patent: January 22, 2002
    Assignee: McGraw-Edison Company
    Inventors: Dennis Alan Walder, Thomas Gerard Dolnik
  • Patent number: 6320732
    Abstract: The present invention provides a power distribution system with a split section panelboard that provides two interior sections. Each section is supplied power from a separate power source. A common bus bridges the two sections. Remotely-operated circuit breakers for both the sections are connected to the common bus. A power interface unit converts power from one of the power sources to provide low voltage power for the circuit breaker motors and a control unit. The control unit in the panelboard controls the operation of the circuit breakers of both the sections.
    Type: Grant
    Filed: July 15, 1999
    Date of Patent: November 20, 2001
    Assignee: Square D Company
    Inventors: Charles C. Norman, Todd M. Munyon, Scott Jordan
  • Patent number: 6292340
    Abstract: This invention relates to an arrangement for sensing a change in pressure from a first state to a second state. This is function in a grid system which has a fault undetected by flow measurement devices. This arrangement consisting of remote monitors powered by a communication system with a stand alone power supply which will sense a significant change in pressure. The monitors, with time delay built in, transmit this change in status to a central host computer for grid system analysis. In normal means for stabilizing the grid system, a remote signal is sent from the host computer to an isolation device for isolating the fault from the remainder of the network system. Subsequently, the host computer notifies the operating department with written notice of the isolation action.
    Type: Grant
    Filed: April 9, 1999
    Date of Patent: September 18, 2001
    Assignee: Electrical Materials Company
    Inventors: Timothy M. O'Regan, James Hannas
  • Patent number: 6275366
    Abstract: The present invention relates to an apparatus and method for distributing electrical power from power substation circuits. The apparatus of the present invention is responsive to overcurrent conditions and selectively actuates a switching network so as to restore power to at least a portion of the users connected to the faulty circuit of the power distribution system.
    Type: Grant
    Filed: July 6, 1999
    Date of Patent: August 14, 2001
    Assignee: KeySpan Technologies, Inc.
    Inventors: Lawrence J. Gelbien, Philip B. Andreas, Werner J. Schweiger
  • Patent number: 6252753
    Abstract: An electrical power distribution system having geographically separated plural generation stations and geographically separated loads is improved by dynamically offsetting a nominal real power operating point of a main control system driving a power control element that variably feeds electrical power onto a network of transmission lines between the stations and the loads in response to deviations in frequency and/or phase of alternating current power on the network. The generation station can include an actuator control circuit for driving the control element in response to a power setting signal, the actuator control circuit incorporating a delay component, an offset signal connection downstream of the actuator control circuit bypassing the delay component. Preferably the system further includes means for monitoring a threshold level of the deviations, and means for inhibiting the means for dynamically offsetting until the deviations exceed the threshold level.
    Type: Grant
    Filed: December 18, 1998
    Date of Patent: June 26, 2001
    Assignee: Southern California Edison Co.
    Inventor: Bharat Bhargava
  • Patent number: 6252751
    Abstract: A method and apparatus for distributing alternating electrical current to motors via a direct current bus is provided. The method and apparatus is directed towards a system wherein a plurality of motors may be controlled by individual motor drives. AC power is supplied to a single active rectifier circuit (as opposed to one per motor) which maintains unity power factor in the AC power and which develops DC power for a DC distribution system. The DC distribution system, which comprises a set of controllable contactors, is in turn coupled to a plurality of motor drive units which convert the DC power into properly conditioned AC power for operating associated motors. The system operates in response to commands issued by a programmable controller. In the event of a fault in one of the drive units, fault isolation may be accomplished by individually turning off each motor drive in sequence via the associated contactor to determine the faulty drive unit.
    Type: Grant
    Filed: August 8, 2000
    Date of Patent: June 26, 2001
    Assignee: Hamilton Sundstrand Corporation
    Inventor: Gregory Z. Rozman
  • Patent number: 6222714
    Abstract: A substation for distributing electric power includes protective relays whose trip points are made to be a function of temperature, the protective relays being used to control the opening and closing of circuit breakers for protecting against fault conditions in at least one of the power input and power output portions of the power distribution system. In one embodiment, a temperature probe which is used to sense the temperature at a selected point of the substation supplies the temperature information to a microcontroller which is programmed to set the trip point of selected protective relays as a function of the sensed temperature.
    Type: Grant
    Filed: March 15, 2000
    Date of Patent: April 24, 2001
    Inventor: Gary R. Hoffman
  • Patent number: 6219623
    Abstract: The invention in the simplest form is a method and apparatus for reliably protecting against island situations with one or multiple power sources connected to an electric distribution grid. The method and apparatus detects variations in the voltage and frequency of the grid. An observed change in grid voltage causes a change in output power that is sufficient to cause an even larger change in grid voltage when the utility AC power source is disconnected. An observed change in grid frequency causes a change in phase or reactive output power that is sufficient to cause an even larger change in grid frequency. If several shifts in voltage or frequency happen in the same direction, the response to the change is increased in an accelerating manner.
    Type: Grant
    Filed: November 24, 1998
    Date of Patent: April 17, 2001
    Assignee: Plug Power, Inc.
    Inventor: Robert H. Wills
  • Patent number: 6198613
    Abstract: A method and apparatus for distributing alternating electrical current to motors via a direct current bus is provided. The method and apparatus is directed towards a system wherein a plurality of motors may be controlled by individual motor drives. AC power is supplied to a single active rectifier circuit (as opposed to one per motor) which maintains unity power factor in the AC power and which develops DC power for a DC distribution system. The DC distribution system, which comprises a set of controllable contactors, is in turn coupled to a plurality of motor drive units which convert the DC power into properly conditioned AC power for operating associated motors. The system operates in response to commands issued by a programmable controller. In the event of a fault in one of the drive units, fault isolation may be accomplished by individually turning off each motor drive in sequence via the associated contactor to determine the faulty drive unit.
    Type: Grant
    Filed: December 23, 1998
    Date of Patent: March 6, 2001
    Assignee: Hamilton Sundstrand Corporation
    Inventor: Gregory Z. Rozman
  • Patent number: 6195242
    Abstract: A method and system to deter cable television (CATV) service theft is disclosed. The method includes identifying a critical area along the service line of the service installation susceptible to tampering. Next a protective means is selected that will provide additional security from tampering to the critical area based on the specific characteristics of the critical area (e.g. light-weight sheathing). Finally, the protective means is applied to the critical area. The method and system are suited for protecting any utility delivered by a service line (e.g., electricity and telephone).
    Type: Grant
    Filed: August 11, 1998
    Date of Patent: February 27, 2001
    Inventor: Tillman C. Ward
  • Patent number: 6169337
    Abstract: The electric power breaker for breaking the electric power is placed on the midpoint of the electric power line from the battery power supply, and the electric power line is extracted from the electric power breaker. In addition, the electric power supply terminal is placed on the midpoint on the electric power line, from which the electric power is supplied to the individual electric load. The electric power distribution and the electric power supply operation to the electric loads are controlled by the multiplex communication. A semiconductor device having a self protection function is used as the switching device for supplying the electric power. The electric power line covered by the electric conductive material is arranged in a loop topology so as to start from the connection point to the battery and pass through the designated positions in the vehicle and return to the battery.
    Type: Grant
    Filed: August 25, 1999
    Date of Patent: January 2, 2001
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Tatsuya Yoshida, Hiroyuki Saito, Shinichi Sakamoto, Mitsuru Koni, Kiyoshi Horibe
  • Patent number: 6163082
    Abstract: The electric power breaker for breaking the electric power is placed on the midpoint of the electric power line from the battery power supply, and the electric power line is extracted from the electric power breaker. In addition, the electric power supply terminal is placed on the midpoint on the electric power line, from which the electric power is supplied to the individual electric loads. The electric power distribution and the electric power supply operation to the electric loads are controlled by the multiplex communication. A semiconductor device having a self protection function is used as the switching device for supplying the electric power. The electric power line covered by the electric conductive material is arranged in a loop topology so as to start from the connection point to the battery and pass through the designated positions in the vehicle and return to the battery.
    Type: Grant
    Filed: August 25, 1999
    Date of Patent: December 19, 2000
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Tatsuya Yoshida, Hiroyuki Saito, Shinichi Sakamoto, Mitsuru Koni, Kiyoshi Horibe
  • Patent number: 6160690
    Abstract: A distribution control system that can isolate a fault section without fail, even if control of load break switches becomes impossible because of a communication error between a control center and a feeder terminal unit. If a communication error takes place between the control center and a particular feeder terminal unit, for example, feeder terminal units associated with the particular feeder terminal unit change the operation mode of their controlling load break switches from non-voltage unopened mode to non-voltage open mode.
    Type: Grant
    Filed: April 13, 1999
    Date of Patent: December 12, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tadashi Matsumoto, Mitsuru Mitani
  • Patent number: 6160696
    Abstract: An electrical power system includes an inverter having a plurality of insulated gate bipolar transistors (IGBTs) and capacitors for converting DC power to AC power and at least one power bus bar including an interconnecting bus bar and a plurality of extension bus bars. The area between the conductors of the interconnecting bus bar and the extension bus bars is minimized to reduce the inductance between the IGBTs and the capacitors. The extension bus bars are each coupled to the interconnecting bus bar and a respective one of the IGBTs and capacitors. An IGBT can be removed from the inverter without removing the interconnecting bus bar or any other IGBT. The capacitors can be positioned at ninety degree angles with respect to the interconnecting bus bar. In one embodiment, the IGBTs are additionally positioned at ninety degree angles with respect to the interconnecting bus bar. In an alternate embodiment, the IGBTs are positioned parallel with respect to the interconnecting bus bar.
    Type: Grant
    Filed: May 4, 1998
    Date of Patent: December 12, 2000
    Assignee: General Electric Company
    Inventors: Ronald Barry Bailey, Dimitrios Ioannidis
  • Patent number: 6147845
    Abstract: A system interconnection device connected between two systems, such as a commercial bus line carrying power from a commercial power line and a private bus line carrying power from a private power generator, is able to connect and disconnect the two systems, and, in the event of a fault, has a current-limiting effect, thus preventing instantaneous voltage drop of the respective bus lines. In the system interconnection device, unit parallel circuits made up of diodes and DC reactors are serially connected so that the diodes thereof have opposite directions. With this structure, in realizing operations equivalent to those of a conventional system interconnection device having a DC reactor between DC terminals of a single-phase rectifying bridge circuit, the number of diodes, which are rectifying elements, can be halved.
    Type: Grant
    Filed: April 7, 1999
    Date of Patent: November 14, 2000
    Assignee: Nissin Electric Co., Ltd.
    Inventors: Yoshio Matsubara, Masakuni Asano, Noriaki Tokuda
  • Patent number: 6141196
    Abstract: A method for obtaining a power system phasor includes sampling a power system signal at instants determined by a nominal power system frequency to provide a plurality of data samples; using the data samples to estimate a phasor having an elliptical trajectory; generating a deviation formula representing a frequency deviation between actual and nominal power system frequencies; and using the deviation formula to perform a coordinate transform of the estimated phasor to provide a scaled phasor having a substantially circular trajectory. If the data samples are unevenly spaced, a method in another embodiment includes minimizing squares of errors between the unevenly spaced data samples and an approximating sinusoidal function of the data samples.
    Type: Grant
    Filed: March 2, 1998
    Date of Patent: October 31, 2000
    Assignee: General Electric Company
    Inventors: William James Premerlani, David Jeremiah Hoeweler, Albert Andreas Maria Esser, James Patrick Lyons, Gerald Burt Kliman, Rudolph Alfred Albert Koegl, Mark Gerald Adamiak
  • Patent number: 6141192
    Abstract: An arcing fault protection system for a switchgear enclosure includes a switching device for rapidly diverting current from the source bus of an electrical distribution system in response to the detection of arcing faults in the system. The switching device, which may comprise a mechanical switch, a solid-state switch or hybrid device, quickly diverts current carried on the source bus to effectively extinguish arcing fault currents present in the distribution system, preventing the generation of gases at high pressures and/or temperatures so as to protect the switchgear equipment from damage.
    Type: Grant
    Filed: November 12, 1998
    Date of Patent: October 31, 2000
    Assignee: Square D Company
    Inventor: Ruben D. Garzon
  • Patent number: 6127741
    Abstract: A vehicular use power feed apparatus comprising a battery and a plurality of power distribution units connected in a loop via power feed lines. Each power distribution unit has a current monitoring circuit, a current amount determination circuit, and a current direction determination circuit, detects the direction of current and magnitude of current flowing through the power feed line, and thereby detects an occurrence of a short-circuit. A control unit exchanges information regarding occurrence of short-circuits with adjoining power distribution units via a multiplex signal transmission unit so as to pinpoint the trouble point. The control unit operates the relay switch circuits on the two sides to break the connection so as to isolate the trouble point in cooperation with the control unit of the adjoining power distribution unit. The other relay switch circuit is operated to establish a connection so as to establish a new power feed line.
    Type: Grant
    Filed: March 16, 1998
    Date of Patent: October 3, 2000
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Yutaka Matsuda, Toshitaka Hara, Takezo Sugimura, Satoshi Kawai
  • Patent number: 6101075
    Abstract: The system first identifies the existence of a fault involving ground using the phase angle difference between negative sequence and zero sequence current on the power line. Phase angle differences within three specific ranges provide an indication of the presence of particular faults. Once a particular fault has been identified, such as a BC-to-ground fault, the fault condition is monitored to determine if the fault evolves, such as to a C-to-ground fault from the BC-to-ground fault. If an evolution is recognized, the protective relay is reset so as to coordinate its operation with downstream protective elements for the evolved fault.
    Type: Grant
    Filed: September 10, 1998
    Date of Patent: August 8, 2000
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventor: Jeffrey B. Roberts
  • Patent number: 6084758
    Abstract: Circuit breakers in an electric power distribution system, such as in a residence or a light commercial facility, are remotely reclosed using a power line communications system such as an X10 or CEBus system, which transmits a reclose signal over the power conductors to a recloser controlling the separable contacts of the circuit breaker in the load center. A remote master unit which generates the reclose signal is connected to an unaffected branch circuit, preferably by plugging into a receptacle located in a convenient part of the house or office remote from the load center. The reclosers may be addressed individually or globally.
    Type: Grant
    Filed: October 26, 1998
    Date of Patent: July 4, 2000
    Assignee: Eaton Corporation
    Inventors: Robert J. Clarey, Joseph Charles Engel
  • Patent number: 6034861
    Abstract: A network protector system is provided in which the internal bussing of the network protector enclosure is constructed to adapt a four-pole circuit breaker for a three-pole network protection operation. This is provided by joining the central two bus conductors of the four line transformer input busses to make a single stab connection which interconnects with two central poles of the four-pole circuit breaker. The load output of the four-pole circuit breaker is interconnected with are overlapping stab which in turn is connected to a signal output bus bar so that the network protector system essentially converts a four-pole circuit breaker and line transformer system to a three-pole output system.
    Type: Grant
    Filed: November 23, 1998
    Date of Patent: March 7, 2000
    Assignee: Eaton Corporation
    Inventors: Steven E. Meiners, Michael F. Magazine, Douglas M. Brandt
  • Patent number: 6023399
    Abstract: In a decentralized control system configuring a network between plural field devices for measuring and controlling the controlled objects and plural upper-level apparatus for communicating data to the field devices and controlling the field devices, and forming a control loop among the devices, in which the field device has a normal communication means for communicating with other devices in a normal operation mode, and an emergency communication means for communicating with other devices in an emergent operation mode, in which the normal communication means and the emergency communication means use their own communication signals and the emergency communication means operates in an asynchronous communication mode. In addition, on the network, a shutdown control means is formed for transmitting a shutdown command signal to the shutdown target control device if necessary by detecting the abnormal state of the individual devices.
    Type: Grant
    Filed: September 22, 1997
    Date of Patent: February 8, 2000
    Assignee: Hitachi, Ltd.
    Inventor: Makoto Kogure
  • Patent number: 6005759
    Abstract: A system for monitoring and controlling an electrical distribution network comprises an electrical distribution substation having a local area network (LAN), a feeder subsystem and a gateway. The feeder subsystem is coupled to the substation and receives electrical energy therefrom for distribution to customers, and includes slave devices for performing switching functions. The gateway provides remote access to the slave devices and the LAN.
    Type: Grant
    Filed: March 16, 1998
    Date of Patent: December 21, 1999
    Assignee: ABB Power T&D Company Inc.
    Inventors: David G. Hart, William L. Peterson, David Uy, W. Michael Egolf
  • Patent number: 5982595
    Abstract: A redundant communications scheme for a protective relay which allows high-speed, reliable, and fault tolerant communications between peer protective devices in a power distribution network. Communications over a selectable primary communication channel are interrupted and switched to a secondary communication channel, which can operate according to a different communication protocol, when a fault is detected on the primary communication channel. The fault detection and switching is performed transparently to the main protective relay processor.
    Type: Grant
    Filed: June 5, 1998
    Date of Patent: November 9, 1999
    Assignee: General Electric Company
    Inventor: Marzio Pozzuoli
  • Patent number: 5956220
    Abstract: An adaptive distance relaying system provides improved performance for parallel circuit distance protection. The system utilizes the parallel circuit's current, when available, in conjunction with measurements of voltage and current on the protected line to compensate for the zero sequence current mutual coupling effect. The sequence current ratio (zero or negative sequence) is used to avoid incorrect compensation for relays on the healthy circuit. If the parallel circuit current is not available and the line operating status is, the best zero sequence current compensation factors are selected accordingly as a next level adaptation. If both the parallel circuit current and line operating status are unavailable, a fallback scheme that offers better results than classical distance protection schemes is employed.
    Type: Grant
    Filed: February 5, 1998
    Date of Patent: September 21, 1999
    Assignees: ABB Power T&D Company Inc., ABB Network Partner AB
    Inventors: Damir Novosel, Yi Hu, Murari M. Saha
  • Patent number: 5943202
    Abstract: Intrinsically compressed device coded data is sent in radio packets with end use programs expanding the coded data for other purposes. Intelligent electronic devices are physically combined with radio communication mean to avert the coupling of interfering electromagnetic transients into the system processing and sending the data.
    Type: Grant
    Filed: September 23, 1996
    Date of Patent: August 24, 1999
    Inventor: Robert W. Beckwith
  • Patent number: 5940260
    Abstract: The present invention relates to an apparatus and method for distributing electrical power from power substation circuits. The apparatus of the present invention is responsive to overcurrent conditions and selectively actuates a switching network so as to restore power to at least a portion of the users connected to the faulty circuit of the power distribution system.
    Type: Grant
    Filed: December 22, 1997
    Date of Patent: August 17, 1999
    Inventors: Lawrence J. Gelbien, Philip B. Andreas, Werner J. Schweiger
  • Patent number: 5933308
    Abstract: An arcing fault protection system for a switchgear enclosure includes a grounding device for rapidly grounding the source bus of an electrical distribution system in response to the detection of arcing faults in the system. The grounding device, which may comprise a mechanical switch, a solid-state switch or hybrid device, quickly diverts current carried on the source bus to ground to effectively extinguish arcing fault currents present in the distribution system, preventing the generation of gases at hazardous pressures and/or temperatures so as to protect the switchgear equipment from damage and to prevent injury to operating personnel.
    Type: Grant
    Filed: November 19, 1997
    Date of Patent: August 3, 1999
    Assignee: Square D Company
    Inventor: Ruben D. Garzon
  • Patent number: 5895988
    Abstract: A safety system for electronic devices having multiple power inputs includes dedicating a different power detector to each power input and includes disabling all of the power inputs upon detection that one input has been disabled. Each of the power inputs is typically a power cord that provides electrical energy to a discrete electrical circuit. Thus, the safety system permits the electronic device to use a different power supply for each electrical circuit, while ensuring that there is no erroneous assumption that disconnecting one of the power cords will de-energize the entire electronic device. In the preferred embodiment, the paths to the power supplies are disabled by opening relay switches, with the switches that are specific to a power cord being in a logical AND arrangement.
    Type: Grant
    Filed: August 21, 1997
    Date of Patent: April 20, 1999
    Assignee: Siemens Business Communication Systems, Inc.
    Inventors: Shmuel Shaffer, William J. Beyda, Peter Kozdon
  • Patent number: 5892645
    Abstract: A protection apparatus for a spot network substation has a plurality of receiving lines connected between a network bus and a plurality of power sources. Each receiving line is connected to a primary switching device, a network transformer and a protector CB. A detector for detecting a phase of each receiving line voltage and a judging unit for judging the detected phase are provided on the primary side of each network transformer. A previously stored basic phase is compared with the detected phase of the receiving line voltage. If there is a lag in the detected phase of the receiving line voltage, it is judged to be a power-stop of the corresponding power source and the protector CB is tripped.
    Type: Grant
    Filed: July 29, 1997
    Date of Patent: April 6, 1999
    Assignees: Hitachi, Ltd., The Tokyo Electric Power Co., Inc.
    Inventors: Yoshiyasu Watanabe, Toru Tanimizu, Kazuo Kano, Yasunobu Kanou, Toshio Horikoshi, Koji Kondou, Ryutaro Yamamoto, Nobuhiro Kuroda
  • Patent number: 5886861
    Abstract: An arc fault detector turns on an electronic switch connecting a power distribution cable to ground thereby actuating a cable limiter to isolate the power distribution cable in response to an arc fault even though the arc fault itself does not create a low enough impedance fault to actuate the cable limiter directly. The electronic switch can be a sacrificial low cost silicon controlled rectifier which is destroyed by the ground fault it creates as long as the let-through current of the cable limiter is below the explosion current of the SCR. A single arc fault detector and SCR which fails as a short circuit can be used to actuate cable limiters at both ends of a short power distribution cable fed at both ends, or preferably separate protection can be provided adjacent both cable limiters.
    Type: Grant
    Filed: September 15, 1997
    Date of Patent: March 23, 1999
    Assignee: Eaton Corporation
    Inventor: Robert Neville Parry
  • Patent number: 5835319
    Abstract: A junction box architecture includes a main circuit breaker, plurality of branch circuit breakers, and an arc detection unit. The main circuit breaker input is connected to main power supply lines, e.g., phase 1 and phase 2 power lines. The main circuit breaker output is connected to respective inputs of branch circuit breakers and to an input of the arc detection unit. The arc detection unit includes an enable output and is configured to generate an enable signal on the enable output. The enable output is coupled to enable inputs of each branch circuit breaker. When no enable signal is present on an enable input of any one branch circuit breaker, the one breaker will not trip. In general, for any one circuit breaker to trip, the breaker must simultaneously detect a high frequency current in the associated branch circuit and receive an enable signal from the arc detection unit.
    Type: Grant
    Filed: April 16, 1997
    Date of Patent: November 10, 1998
    Assignee: General Electric Company
    Inventors: Kenneth Brakeley Welles, II, Thomas Michael Palmer
  • Patent number: 5818673
    Abstract: An electric power distribution system is shown where even if supply of electric power is interrupted, other normal electric part systems can be operated. A number of electric power distribution portions are supplied with electric power through at least two systems of electric power lines. The amounts of electric currents in the two systems of the trunk lines respectively are detected and monitored by a sensor and each current detection portion. Moreover, a controller controls a switch corresponding to a sensor which has detected an abnormal value among output values from a number of current detection portions to make non-conductive the trunk line from which the abnormal value has been detected. If a fault takes place in, for example, the trunk line between the electric power distribution portions, the two ends of the trunk line respectively are disconnected by the switch.
    Type: Grant
    Filed: April 2, 1997
    Date of Patent: October 6, 1998
    Assignees: Harness System Technologies Research, Ltd., Sumitomo Wiring Systems, Ltd., Sumitomo Electric Industries, Ltd.
    Inventors: Akio Matsumaru, Motonori Kido, Yoshiyuki Miyazaki, Hideaki Toyama
  • Patent number: 5784237
    Abstract: A control method and apparatus is provided for isolating network faults via the communication between neighboring network locations and the control of sectionalizing switches at the network locations. Control apparatus is provided at particular network locations which responds to detected fault conditions and communicates the detected fault condition to the control apparatus at neighboring network locations. The appropriate control apparatus, in response to the information received from neighboring network locations, opens a sectionalizing switch to isolate the fault condition. In one particular arrangement, each control apparatus that detects a fault condition sends a signal to appropriate source-side, neighboring control apparatus to inhibit the source-side control apparatus from opening their respective sectionalizing switches. Further, any control apparatus that detected a fault condition and that does not receive an inhibiting signal, controls its sectionalizing switch to open.
    Type: Grant
    Filed: November 29, 1996
    Date of Patent: July 21, 1998
    Assignee: S&C Electric Company
    Inventor: Andrew M. Velez
  • Patent number: 5784238
    Abstract: A coordinated cluster-tool energy distribution system provides a systems level approach to supplying all process energy needs for such industrial applications as those found in the semiconductor manufacturing industry, e.g. a single-wafer or multiple chamber processing chamber. The system is preferably provided as an integrated whole, rather than as a piece-meal collection of various energy distribution elements.
    Type: Grant
    Filed: August 1, 1996
    Date of Patent: July 21, 1998
    Assignee: Applied Materials, Inc.
    Inventors: Eric A. Nering, Dan R. Fleming
  • Patent number: 5773980
    Abstract: A one-terminal process for locating a fault associated with a multi-phase electric power transmission system is disclosed. The process is based on the principle that the impedance in a fault can be determined by correcting errors due to the interaction of fault resistance and load current. The fault may be a phase-to-ground fault or a multiple-phase fault.
    Type: Grant
    Filed: January 30, 1997
    Date of Patent: June 30, 1998
    Assignee: ABB Power T&D Company, Inc.
    Inventor: Lifeng Yang
  • Patent number: 5754382
    Abstract: A power transmission system includes a transmission line unit for three phases connected to three gas insulated transmission lines and a standby transmission line unit for a phase connected to a standby gas insulated transmission line connected with each other. A connection bus is provided at a branch part of each breaker in the transmission line unit for three phases, via the breaker. The connection bus is connected to a branch bus provided between the breaker in the transmission line unit of a gas insulated switch gear for three phases and the main buses, and to the standby transmission line unit.
    Type: Grant
    Filed: August 19, 1996
    Date of Patent: May 19, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Takanobu Aoyama, Tadasuke Yamamoto
  • Patent number: 5737166
    Abstract: Protective equipment in a bipole converter station of an installation for power transmission by means of a high voltage direct current having main circuits on the dc side of the station. The main circuits have two separate pole parts, one part for each one of the two poles of the station, and a bipole part that is common to both poles. Measuring means in the station form measurement signals which correspond to operating quantities of the station. The measurement signals are supplied to the protective equipment. The protective equipment, dependent on the measurement signals and in their quarters with predetermined algorithm, takes measures to avoid permanent faults by influencing the operation of the station. The protective equipment has a pole protective means for each pole part and a bipole protective means for protection of the bipole part.
    Type: Grant
    Filed: April 1, 1996
    Date of Patent: April 7, 1998
    Assignee: Asea Brown Boveri AB
    Inventor: Ingvar Hagman
  • Patent number: 5719787
    Abstract: A method for on-line dynamic contingency screening of electric power systems employs a sequence of contingency classifiers which are based on a method for finding the controlling unstable equilibrium point of the power system known as the boundary of stability region based controlling unstable equilibrium point method (BCU method). Dynamic security assessment of the power system is accomplished by evaluating the power system's response to a plurality of postulated disturbances known as contingencies. The BCU classifiers determine which of these contingencies are definitely stable, and require no further analysis. Other contingencies which are either classified as being unstable or undecided are then applied to a time-domain simulation program to determine if they are in fact unstable, and therefor warrant further action.
    Type: Grant
    Filed: May 15, 1996
    Date of Patent: February 17, 1998
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Hsiao-Dong Chiang, Cheng-Shan Wang
  • Patent number: 5712756
    Abstract: A substation includes standard arresters installed near a bushing of a power transmission line entrance and at a connecting bus of a transformer and one or more high voltage arresters having a discharge voltage 10 to 30% higher than a standard arrester. Each high voltage arrester uses zinc oxide elements and is disposed on a line side of a line entrance breaker and/or near an open end of a double main bus in the substation.
    Type: Grant
    Filed: March 4, 1996
    Date of Patent: January 27, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Jun Ozawa, Kazuya Ooishi, Katsuji Shindo, Takahide Matsuo, Yoshitaka Yagihashi, Takeo Yamazaki