Patents Represented by Attorney, Agent or Law Firm Hanh T. Pham
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Patent number: 6327162Abstract: A static series voltage regulator (SSVR) for an electric power distribution system protects a load on a feeder branch from voltage dips by boosting voltage under certain conditions. The SSVR contains a 3-phase voltage source inverter and a source bridge, fed from a source, supplying the dc side of the inverter. A series transformer is connected between the power source and a load coupling the inverter output to appear between the power source and the load. A surge filter connected in parallel with the series transformer protects the load from fast front voltage pulses produced by the inverter, and isolation and bypass switches isolate the inverter and series transformer from the power source and load. The inverter is controlled so that during normal operation it acts as a short on the series transformer, and, during a fault that causes a dip in the source voltage, it injects voltage in series with the source voltage to provide a boost action to maintain load voltage at a desired magnitude and balance.Type: GrantFiled: March 21, 1996Date of Patent: December 4, 2001Assignee: General Electric CompanyInventors: Einar V. Larsen, Kara Clark, Reigh Walling
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Patent number: 5821464Abstract: A power busway distribution section length which may be adjusted before, during, or after installation to better facilitate proper busway location and reduce installation and modification costs. The section length comprises two busway stubs which slide independently between a center busway splice-plate joint. Overlapping sheet metal enclosures are used to provide protection from inadvertent contact with live bus bars and allow the busway section length to be adjusted to a discrete length.Type: GrantFiled: August 23, 1996Date of Patent: October 13, 1998Assignee: General Electric CompanyInventors: Eric J. Graham, Clarence W. Walker, Louis A. Rosen
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Patent number: 5774328Abstract: An electronic energy meter register enclosure which, in one embodiment, includes ribs and snaps configured to engage and snugly hold a printed circuit board in place is described. Openings in a meter frame align with openings in the enclosure, and threaded bolts securely engage the enclosure to the meter frame. The enclosure also includes, in the one embodiment, a snap which snaps on the rear bearing of the meter for facilitating holding the register enclosure in place. The enclosure further includes a shroud, and sidewalls of the shroud are configured to be closely positioned proximate the sides of the meter frame to reduce amount of ambient light allowed in the cavity of the shroud. The combination of the meter disc, the meter mechanical register, the meter frame and the shroud almost completely shields the electrical components of the register circuit board from harmful UV exposure that would create degradation and excessive heat build-up.Type: GrantFiled: April 15, 1996Date of Patent: June 30, 1998Assignee: General Electric CompanyInventors: William O. Rector, Patrick J. Horan, David Dopp
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Patent number: 5764155Abstract: A dynamic data exchange (DDE) server which allows external programs to access power management data is presented. The DDE server provides a mnemonic cross reference between register items and standardized, alphanumeric parameter names. This mnemonic interface allows the user to retrieve data from a device without knowledge of the actual device register item number. Also, the DDE server automatically performs time synchronizing for all supported devices and provides a consistent waveform and event interface. The DDE server is optimized for either the Modbus RTU or Ethernet protocol. The DDE server includes toolkit functions which are used to maintain DDE communication and protocol timers and to maintain active topic and item lists. The DDE server acts as a link between a client requesting device data and a field device which can provide the data. The DDE server communicates to the field device through communication ports and to the client via DDE message link.Type: GrantFiled: April 3, 1996Date of Patent: June 9, 1998Assignee: General Electric CompanyInventors: Veronica Kertesz, Don Whitehead, James Burke, Harshad Tanna, Subhash Garg, A. Rajeshwar Rao, S. S. Lakshmi, S. Mishra, J. Lakshminarayana, Pradeep Kumar Tamanna, B. Ravi Kumar, M. Kailashnath
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Patent number: 5715390Abstract: An electricity meter having a protected enabling scheme for activating meter options and upgrades is presented. The meter has a unique serial number, which includes bit-flags indicating which options have already been enabled, stored in the non-volatile RAM. Each option which is not enabled must be requested and a password verified before it can be utilized. At least one password is stored in a read protected location in the non-volatile RAM. The meter is in communication with a computer, e.g., a desktop or laptop type of computer. The password is generated by processing a secret software key and the unique serial number of the meter with an authentication algorithm. The computer is loaded with an upgrade software program, which includes the authentication algorithm. A hardware key which stores a secret software key is attached to a parallel port of the computer.Type: GrantFiled: November 30, 1995Date of Patent: February 3, 1998Assignee: General Electric CompanyInventors: Mark E. Hoffman, John E. Hershey
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Patent number: 5673196Abstract: Line voltage and line current signals are sensed on a power line having at least one conducting path. The sensed line voltages and line currents are converted into a digital signal. A phase-to-neutral voltage signal and phase current signal are computed from the digital signal to thereby define a phase of the power line. An interval of orthogonality is determined from the sensed voltage and current signals, coinciding with passage of an integral number of cycles of a fundamental frequency reference signal which is computed from the computed phase-to-neutral voltage signal. A vector metering quantity is computed for the determined interval of orthogonality from the computed phase-to-neutral voltage signal and the computed phase current signal. The vector metering quantities to be computed may be identified and computed based upon an associated detent. The vector metering quantity is also computed based on an identified circuit topology.Type: GrantFiled: November 30, 1995Date of Patent: September 30, 1997Assignee: General Electric CompanyInventors: Mark E. Hoffman, Roland J. Provost, Thomas Maehl, Gregory P. Lavoie, Mark J. Plis, David D. Elmore, Warren R. Germer, Jeffrey W. Mammen, Donald F. Bullock, Sivarama Seshu Putcha, Daniel A. Staver, Arthur C. Burt, Curtis W. Crittenden, Ellen D. Edge
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Patent number: 5668705Abstract: A wide range single-phase/polyphase switching power supply is presented. The power supply comprises first and second full wave bridge circuits. The rectified outputs of the bridge circuits are connected to a preregulator circuit, i.e., a FET circuit, where the primary input voltage from bridge circuits is limited. The output of the preregulator circuit is presented to a filter circuit. A current mode controller circuit operates at a fixed frequency with a variable duty cycle. An output of the current mode controller circuit drives the gate of a switching FET, at the fixed frequency and variable duty cycle. The aforementioned filtered voltage signal and the drain of the switching FET are connected across a first winding on the primary side of a flyback transformer. A second winding on the primary side of the flyback transformer is connected across Vcc, the supply voltage of the current mode controller circuit.Type: GrantFiled: November 30, 1995Date of Patent: September 16, 1997Assignee: General Electric CompanyInventors: Richard A. Balch, Raymond B. Ridley, David D. Elmore, Warren R. Germer