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: 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: 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. In one embodiment those comparisons are done by determining “relative” phase change rate phasors by calculating the product of one incoming phase difference phasor with the conjugate of another incoming phase difference phasor.

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 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.

Abstract: A current limiting circuit breaker having for each pole, a pair of main contacts separable upon operation of a thermally and electromagnetically operable tripping device and a pair of auxiliary contacts for current limiting in series with the main contacts and in parallel with a transformable resistor having a positive temperature coefficient of resistance. The auxiliary contacts are separable when an electromagnet is energized by a fault current which simultaneously energizes a field magnet to produce a transverse magnetic field across the auxiliary contacts and the arc formed between them when separating. This simultaneous action of electromagnet and field magnet coacting for rapid contact separation and lengthening of the arc upon flow of a fault current serves to increase arc voltage almost instantaneously to that of the source, about which time the fault current is totally shunted into the resistor.