Abstract: A circuit protection system is provided that provides a dynamic delay time to an upstream circuit breaker if a fault is detected in a circuit where the dynamic delay time can be based upon the location of the fault, such as the nearest downstream circuit breaker.

Abstract: A method and apparatus for collecting power distribution system data is provided. The method includes communicatively coupling a plurality of node electronic units to a digital network, communicatively coupling at least one central control processing unit (CCPU) to the digital network, executing a data capture software module running on the at least one CCPU wherein the module includes a data capture buffer and a secondary buffer, and activating the data capture module in response to a triggering event. The apparatus includes a plurality of node electronic units, at least one central control processing unit (CCPU), and a data capture software module running on the at least one CCPU wherein the module includes a data capture buffer and a secondary buffer wherein the module is configured to collect data in the data capture buffer and the secondary buffer, and the module is configured to activate in response to a triggering event.

Abstract: A method and system for determining a configuration of a redundant critical control system is provided. The method includes receiving power distribution system operating characteristic information, using a computer, determining a plurality of alternative configurations of the power distribution system that are consistent with the operating characteristic information and determining efficiency characteristics of each of the alternative configurations, and selecting a configuration from the plurality of alternative configurations. The system includes a computer system configured to receive power distribution system operating characteristic information, determine a plurality of alternative configurations of the power distribution system that are consistent with the operating characteristic information and determine life-cycle cost characteristics of each of the alternative configurations, and select a configuration from the plurality of alternative configurations.

Abstract: A method and apparatus for monitoring a centrally controlled power distribution system is provided. The method includes sampling an electrical current flow in the centrally controlled power distribution system, transmitting the sampled current signals to a central control processing unit, determining a ground fault presence and location based on the current signals received from all of the node electronics units, and isolating the determined ground fault by opening circuit breakers supplying power to the fault. The apparatus is configured to sample an electrical current flow in the centrally controlled power distribution system, transmit the sampled current signals associated with each circuit breaker to a central control processing unit, determine a ground fault presence and location based on the current signals received from all of the node electronics units in the power distribution system, and isolate the determined ground fault by opening circuit breakers supplying power to the fault.

Abstract: A method for communicating information bundled in digital message packets via a digital network communication system is provided. The digital network communication system a sample source and each packet includes a header and a communication payload area. The method includes sampling the source at a first sample rate, selecting at least one decimation of the samples based on at least one of a plurality of algorithmic data rates and a channel bandwidth, determining a packet rate based on a plurality of algorithmic latency requirements, and transmitting the digital message packet containing decimated data on the digital network.

Abstract: A method for synchronizing a plurality of processors within a computer system is provided. The computer system includes a plurality of processors that are each communicatively coupled to a respective network wherein each network is independent of each other network. The method includes receiving a plurality of input signals at a first rate from at least one source, transmitting the input signals to a reference object, and transforming the input signal to a known temporal reference. The apparatus is configured to receive a plurality of input signals at a first rate from at least one source, transmit the input signals to a reference object, and transform the input signal to a known temporal reference.

Abstract: A method and system for monitoring and controlling a power distribution system is provided. The system includes a plurality of circuit breakers and a plurality of node electronic units. Each node electronic unit is mounted remotely from an associated circuit breaker that is electrically coupled with one of the node electronic units. The system also includes a first digital network, and a first central control unit. The first central control unit and the plurality of node electronic units are communicatively coupled to the first digital network. The method includes receiving digital signals from each node electronic unit at the central control unit, determining an operational state of the power distribution system from the digital signal, and transmitting digital signals to the plurality of node electronic units such that the circuit breakers are operable from the first central control unit.

Abstract: A method and apparatus for operating a centrally controlled power distribution system is provided. The power distribution system includes a plurality of circuit breakers, each circuit breaker coupled to a single node electronics unit, the node electronics unit includes a plurality of processors and a memory, and the node electronics unit is communicatively coupled to at least one central control processing unit through an associated network. The method includes triggering a first node electronics unit process with a processor interrupt, and triggering a second node electronics unit process with at least one of a background polling of process execution flags and scheduled processor interrupts. The apparatus includes a software program code segment configured to trigger a first node electronics unit process with a processor interrupt, and trigger a second node electronics unit process with at least one of a background polling of process execution flags and scheduled processor interrupts.

Abstract: A method for predicting zero crossings of fault currents in a multi-phase power system includes sensing a fault current in each respective phase, estimating parameters of a model of each respective fault current, and independently using the estimated parameters for each respective fault current to predict a zero crossing of the respective fault current.

Abstract: A method of detecting faults on a power transmission line system includes simultaneously measuring phase current samples at each phase of each transmission terminal; calculating real and imaginary phaselets comprising partial sums of the phase current samples; for each phaselet, calculating a respective partial sum of squares of each phase current sample; calculating the sums of the real and imaginary phaselets over a variable size sliding sample window; calculating real and imaginary phasor components from the phaselets and a sum of the partial sums of the squares over the sample window; using the sums of the real and imaginary phaselets, the real and imaginary phasor components, and the sum of the partial sums of the squares to calculate a sum of squares of errors between the phase current samples and a fitted sine wave representative of the real and imaginary phasor components; using the sum of squares of errors to calculate a variance matrix defining an elliptical uncertainty region; determining whether a

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.

Abstract: Methods and apparatus for facilitating current transmission through a circuit breaker are described. In an exemplary embodiment of the apparatus, a coupler that includes a copper conductive ring having an inner annular wall is provided. The coupler is electrically coupled to the line terminal. A bore extends through the ring, and the bore is sized so that the shaft can extend therethrough. A plurality of copper bristles extend radially inward from the ring inner annular wall, and the bristles are in electrical contact with the conductive ring. The bristles also are in electrical contact with shaft when shaft extends through ring bore. At least some bristles extend sufficiently radially inward from the ring inner wall so that free ends of at least some bristles are in electrical contact with the shaft when the shaft extends through the bore.

Abstract: A method of detecting faults on a power transmission line system includes simultaneously measuring phase current samples at each phase of each transmission terminal; calculating real and imaginary phaselets comprising partial sums of the phase current samples; for each phaselet, calculating a respective partial sum of squares of each phase current sample; calculating the sums of the real and imaginary phaselets over a variable size sliding sample window; calculating real and imaginary phasor components from the phaselets and a sum of the partial sums of the squares over the sample window; using the sums of the real and imaginary phaselets, the real and imaginary phasor components, and the sum of the partial sums of the squares to calculate a sum of squares of errors between the phase current samples and a fitted sine wave representative of the real and imaginary phasor components; using the sum of squares of errors to calculate a variance matrix defining an elliptical uncertainty region; determining whether a

Abstract: A drive system comprises a rotor position and velocity tracker adapted to decouple fundamental frequency effects of a zero sequence signal of an induction machine from the zero sequence signal and to use a resulting error signal to estimate a position and a velocity of a rotor of the induction machine.

Abstract: A method of detecting faults on a power transmission line system includes simultaneously measuring phase current samples at each phase of each transmission terminal; calculating real and imaginary phaselets comprising partial sums of the phase current samples; for each phaselet, calculating a respective partial sum of squares of each phase current sample; calculating the sums of the real and imaginary phaselets over a variable size sliding sample window; calculating real and imaginary phasor components from the phaselets and a sum of the partial sums of the squares over the sample window; using the sums of the real and imaginary phaselets, the real and imaginary phasor components, and the sum of the partial sums of the squares to calculate a sum of squares of errors between the phase current samples and a fitted sine wave representative of the real and imaginary phasor components; using the sum of squares of errors to calculate a variance matrix defining an elliptical uncertainty region; determining whether a

Abstract: A radio frequency (RF) or other form of detector detects discharges of an insulated system which can occur when electrical insulation becomes wet, for subsequent analysis and decision processes. Additionally, for RF detection, a frequency selector can be used to select a “quiet” region of the discharge spectrum before demodulation and further analysis and decision. Finally, redundant sets of such filters avoid the need to continuously reconfigure the detection system.

Abstract: A method of detecting faults on a power transmission line system includes simultaneously measuring phase current samples at each phase of each transmission terminal; calculating real and imaginary phaselets comprising partial sums of the phase current samples; for each phaselet, calculating a respective partial sum of squares of each phase current sample; calculating the sums of the real and imaginary phaselets over a variable size sliding sample window; calculating real and imaginary phasor components from the phaselets and a sum of the partial sums of the squares over the sample window; using the sums of the real and imaginary phaselets, the real and imaginary phasor components, and the sum of the partial sums of the squares to calculate a sum of squares of errors between the phase current samples and a fitted sine wave representative of the real and imaginary phasor components; using the sum of squares of errors to calculate a variance matrix defining an elliptical uncertainty region; determining whether a

Abstract: A method for internal fault detection comprises determining whether a local current on a local transmission line terminal exceeds a variable first fault level threshold; if so, determining whether a remote current on a remote transmission line terminal exceeds a variable second fault level threshold; and if so, comparing phases of the local and remote currents. The method can include determining local and remote uncertainty factors for the local and remote currents and using the uncertainty factors to adjust the variable thresholds. The method can further include measuring a current on a local transmission line terminal and bandpass filtering the measured current to obtain the local current.

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.

Abstract: A method for synchronizing clocks includes: sensing currents at multiple terminals; exchanging current and time stamp data between local and remote terminals; estimating a frequency deviation between local clock and power system frequencies; estimating a time based phase deviation with the time stamp data; estimating a current based phase deviation between the currents at the local and remote terminals; and using the frequency, time based phase, and current based phase deviations to synchronize the local clock. An integer counter value of the clock can be controlled by adjusting the integer counter value based on a sum of fractional counter values to increase clock resolution.