Abstract: A directional fault location and isolation system for a three phase electric power circuit that identifies a faulted segment by determining the direction of the fault at multiple tap points in the electric power circuit. The directional fault controller, which may be a centralized controller or a number of peer-to-peer controllers located at the tap points, includes communication equipment for exchanging information with the monitoring equipment and the sectionalizing equipment at each sectionalizing control point, which includes the tap points and may also include the substations. The controller also includes processing equipment that determines the directionality of a fault on the power line at each current monitoring device, identifies a faulted line section by identifying a change in the directionality of the fault associated with the faulted line section, and operates one or more of the sectionalizing switches to isolate the faulted line section from the circuit.

Abstract: A high-impedance system that utilizes asynchronous, line-mounted single-phase current and voltage sensors with rolling data logs and a common clock or other event trigger to synchronize the signals to a common time scale whenever a fault event is detected. The use of asynchronous, single-phase current and voltage angle sensors with rolling data logs, along with a common clock to synchronize the signals to common time scale whenever a fault event is detected, avoids the need for simultaneous three-phase current measurement. Integration of information, triggered by the detection of a loss or sufficient change of current on three or four (with a neutral current) devices, is used to determine the presence and direction of high-impedance faults and then report it, typically to a central control center via SCADA or another communication system, which implements fault isolation.

Abstract: A communication and control system for a high voltage power line using an energy harvesting power supply to avoid batteries in the communication components maintained at line voltage. The energy harvesting power supply utilizes scavenged backscatter power received from a transceiver maintained at ground potential or a power supply with a super-saturating magnetic flux core, such as a mu-metal core, to harvest electromagnetic field energy from the power line. The communication equipment maintained at line voltage communicates information to the transceiver maintained at ground potential by modulating backscatter energy reflected from the beam transmitted by the ground level transceiver to minimize the power requirement of the communication equipment maintained at line voltage. Response equipment includes capacitors, voltage regulator, voltage sag supporter, circuit interrupter, remote communication equipment, reporting and analysis system.

Abstract: A current monitoring device (CMD) with a set of electromagnetic field sensors located within one or more grounded housings positioned within the combined electromagnetic fields generated by one or more electric power lines. The CMD includes electronics, typically located within the grounded housings, defining impedance networks that combine the measurements received from the field sensors to create output signal indicative of electric current values for the phase conductors. The housings can be conveniently attached and to transmission line towers, distribution line poles, and high voltage power line supports in transmission and distribution substations. The CMD controls response equipment, such as a circuit interrupter that responds to current disturbances detected by the CMD. The CMD may also include communication for sending the current values to a remote controller, such as a central control station, that implements a wide range of response equipment.

Abstract: A current pause device configured to enhance the operation of transmission and distribution line circuit interrupters by delaying the voltage build across the circuit interrupter arc gap for a time period sufficient to allow the dielectric characteristic of the medium within the arc to recover. This allows the circuit interrupter to break the circuit at a lower arc gap voltage than would occur without the current pause device. The current pause device includes a conductive arcing horn and an insulator interposed in the arcing horn to create a conductive gap in the arcing horn and a voltage protection arrangement to limit the voltage across the current pause device and thereby prevent a voltage breakdown across the current pause device. Specifically, the voltage protection arrangement includes a diode connected to the arcing horn in parallel with the insulator and a dielectric spark gap device connected in parallel across the insulator.

Abstract: An electric power monitoring and response system using electromagnetic field sensors located remotely beside the phase conductors. The system determines unknown system variables for one or more three-phase power lines based on measured values obtained form the field sensors and, in some cases, known power system values. For a given physical configuration, the field sensors may include a magnetic or electric field sensors, and the known system values as well as the unknown system variables may include phase currents, phase voltages and distances defining the physical configuration of the system. The response equipment may be a display, a circuit interrupting device, a voltage regulator, a voltage sag supporter, a capacitor bank, communication equipment, and reporting system.

Abstract: A voltage sag and over-voltage compensation device for an AC electric power distribution system employing cascaded switching devices and a pulse-width modulated transformer. Each stage of the cascaded switching device includes a switching element located within a full-bridge rectifier circuit to allow bi-directional switching through each switching element (i.e., switching through the same switching element during the positive and negative portions of the AC voltage cycle). Each full-bridge rectifier also includes a snubber circuit connected in parallel with a corresponding switching element to absorb the current discharge caused by switching the input power supply to the transformer through the corresponding switching device under non-zero current conditions.

Abstract: A voltage sag and over-voltage compensation device for an AC electric power distribution system employing cascaded switching devices and a pulse width modulated autotransformer. The autotransformer typically includes lower, center, and upper poles or taps with cascaded switching devices for selectively connecting the voltage source (i.e., a phase of the distribution line) between the lower pole and the center or upper poles. Each stage of the cascaded switching device includes a switching element located within a full-bridge rectifier circuit to allow bi-directional switching through each switching element (i.e., switching through the same switching element during the positive and negative portions of the AC voltage cycle).