Abstract: A system comprising an interface configured to condition a signal associated with a power system; a clock module configured to generate a synchronization signal; and a module coupled to the interface and configured to digitize the signal from the interface; filter the digitized signal; and generate a time-shifted, digitized signal in response to the filtering and the synchronization signal.

Abstract: The invention compares geographically remote locations on a power grid by determining at each location the amount of change to phasor measurements for a period of time, and then comparing the determined change values from each location to determine relative differences in values as an indicator of the stability of the power grid. One embodiment calculates the product of the node's most recent phasor and a complex conjugate of that nodes previous phasor sample to produce a phase difference phasor for that node. The various phase difference phasors are sent to a monitoring location (which may be local for one of the phasors) and comparisons made among the phase difference phasors to assess the amount of load imbalance among the nodes that are being compared.

Abstract: A uniquely configured electrical power transmission data recorder system generates a first data stream. The first data stream is a digitized form of an electric power signal being monitored. The data recorder calculates a second data stream from the first data stream. The second data stream is a phasor representation of the electrical power signal being monitored. Vectors of the second data stream are provided at a lower frequency than vectors of the first data stream. The data recorder system associates different fault triggers with each of the data streams. When the data recorder detects a condition that activates one or more of the fault triggers, it generates a power fault record. The power fault record has a prefault portion corresponding to a time period before a fault is detected and a postfault portion corresponding to a time period after the fault ceases. The system may include a number of different processors dedicated to different power monitoring and data recording tasks.

Abstract: A temperature compensation system includes a first oscillator to generate a number of pulses which vary from a desired frequency as a function of temperature of the first oscillator. The system also includes a second oscillator to generate digital pulses at a corrective frequency which is greater than the desired frequency. A sensor provides an temperature signal for the first oscillator. A digital memory has a digital error table addressable by a signal corresponding to the temperature signal to provide a number of pulse errors corresponding to temperature error for each of the number of pulses. Each pulse error is a function of the corrective frequency and a temperature versus frequency characteristic of the first oscillator. An accumulator receives each pulse error to generate a cumulative error corresponding to one of the number of pulses. A variable delay device counts a quantity of corrective pulses from second oscillator to provide a delayed output pulse in accordance with the desired frequency.

Abstract: A fault detection system for monitoring at least one operating parameter of an AC power transmission line includes current and/or voltage transducers connected to the transmission line for providing an analog signal representative of at least one time varying parameter of the AC power transmission. An analog-to-digital (A/D) converter samples the analog signal and produces digital sample words representing the signal. The digital sample words are provided by a data bus to a high speed DSP module which includes a number of fault trigger components for operating on the digital sample words to detect a disturbance. The DSP module generates a trigger signal when a disturbance is detected by one of the fault trigger components.