Abstract:
A method for determining the DC current flowing through an AC power meter. The internal impedance of the distribution transformer is first sensed, then the DC voltage in the AC voltage waveform is measured and finally the measured DC voltage is converted to DC current.
Abstract:
A system and methods that enable a restoration scheme for power distributi on systems that is independent of power distribution system component configuration, the number of power distribution system components, and component settings are provided. In a power distribution system, a number of intelligent reclosers having restoration control modules are deployed that execute a restoration scheme. The intelligent reclosers constantly poll cooperating power distribution lines to determine changes in current or voltage provided by the power distribution lines. In the event of a power distribution system fault, the reclosers act in accordance to a predefined restoration scheme to reanimate the unaffected portions of the failing power distribution system.
Abstract:
An electronic energy meter senses input voltage and current signals and processes them to generate a plurality of power measurements. The meter includes a processing system (14/16) for selecting one of the plurality of power measurements and for generating a pulsed test signal related to the selected power measurement for testing the operation of the meter, and an optical communications port (40) coupled to the processing system for transmitting the pulsed test signal from the meter to a testing device external to the meter.
Abstract:
A shift register [Fig. 1 (20)] is utilized to provide a 90° delay in a pulse width modulated current signal [Fig. 2 (E)I to determine volt-amperes reactive. The shift register is associated with a clock (22) that provides a preselected frequency that, in combination with the number of stages in the shift register, delays the pulse width modulated current signal by an amount equivalent to one-quarter period (π/2) of the current waveform in the metered circuit. After delaying the pulse width modulated signal by 90°, the shifted signal is multiplied (24) by a voltage signal [Fig. 3 (G)] that represents the voltage in the metered circuit and the resulting product signal (Fig. 3 (1)] is input to a voltage-to-frequency converter (28).
Abstract:
Unique systems, methods, techniques and apparatuses of a substation phasor data concentrator (ssPDC) is disclosed herein. One exemplary embodiment is a method for operating an electrical substation including a merging unit (MU), a phasor measurement unit (PMU), and a substation phasor data concentrator (ssPDC). The method includes receiving, with the MU and the PMU, input information corresponding to a set of electrical characteristics of the electrical substation; measuring, with the MU, the input information; measuring, with the PMU, the input information; a and estimating, with the ssPDC, electrical characteristics of the electrical substation using the received false measurement and the one of the MU measurement and the PMU measurement, determining in substantially real time the false measurement does not correspond to the set of electrical characteristics using the estimated electric characteristics, and replacing the false measurement with the received the one of the MU measurement and the PMU measurement.
Abstract:
Methods and systems for secured control of circuit breakers in an electric power substation against undesired direct operation. Consequences of a malicious action are prevented or mitigated using a validation approach that either blocks the command or ensures a negligible effect on system operation. An example method, suitable for implementation in a monitoring device in an electric power substation, includes receiving a command to open or close a circuit breaker. In response, one or more state parameters for the electric power network that comprises the substation are then predicted, the predicted state parameters reflecting an operating state for the network under the assumption that the received command is executed. The method further comprises comparing the predicted one or more state parameters to corresponding operational limits. Execution of the command is then blocked, in response to determining that one or more of the predicted state parameters violate the corresponding operational limits.
Abstract:
Systems and methods for identifying faulted segment(s) in a multiphase power network may include receiving a current measurement that was measured during a fault, obtaining a set of equivalent sequence impedances for the segments, building a set of sequence bus impedance matrices, selecting a segment, calculating coefficients for the segment based on the set of equivalent sequence impedances for the segment and the sequence bus impedance matrices, calculating an estimated per unit fault distance for the segment based at least partially on the current measurement and the coefficients, identifying the segment as a potentially faulted segment if the estimated fault distance for the segment is between about zero and about one, and repeating for each of the segments the calculating coefficients, calculating an estimated per unit fault distance, and identifying as a potentially faulted segment if the estimated fault distance for the segment is between about zero and about one.
Abstract:
A system and method for delivering targeted information to a user is provided. The user initiates a request for information by capturing or scanning a bar code associated with an object. The bar code is decoded and the decoded information is presented to the user. The decoded information and GPS coordinates of the user's scanning device is used to directly route the user to detailed information about the object that was scanned or the appropriate service department for servicing the object. The detailed information about the object includes but is not limited to product and system specifications, technical manuals and CAD drawings. A history of product scans is stored on the user's device and available for upload to the cloud. A portal is provided for accessing product scans and installed base information stored on the cloud.
Abstract:
Arc resistant enclosures for dry-type transformers. More particularly, transformer enclosures having one or more arc-resistant features, including arc channels, arc fault dampers, and arc fault plenums, and methods for providing same.