Class / Patent application number | Description | Number of patent applications / Date published |
361047000 | In a polyphase system | 21 |
20090296289 | High Resistance Ground Protection Employing AC Drive Characteristics - A method and apparatus for identifying a ground fault in a motor drive system that includes at least one three phase power conditioner that is linked to three phase supply lines and to positive and negative DC buses, the method comprising the steps of controlling the power conditioner at an operating frequency to convert power, while controlling the power conditioner to convert power, controlling the power conditioner to apply a common mode signal on each of the three phase supply lines where the common mode signal has a frequency that is different than the operating frequency, sensing the common mode signal on at least one of the three phase supply lines and when the common mode signal on the at least one of the three phase supply lines is greater than a threshold level, indicating that a ground fault has occurred. | 12-03-2009 |
20100014198 | Method, Apparatus and Computer Program Product for Fault Protection - An apparatus is provided for fault protection. The apparatus may include one or more electronic components configured to receive a single phase-to-ground fault signal and a double phase-to-ground fault signal subsequent to receiving the single phase-to-ground fault signal. The one or more of electronic components may be further configured to provide for a delay while the single phase-to-ground fault signal indicates that a single phase-to-ground fault is present on the ungrounded power system and the double phase-to-ground fault signal indicates that the double phase-to-ground fault is present on the ungrounded power system. The delay may allow for an opportunity to isolate a phase-to-ground fault on a first phase from a phase-to-ground fault on a second phase. Associated methods and computer program products are also provided. | 01-21-2010 |
20100091419 | MOTOR DRIVE GROUND FAULT DETECTION - A motor drive ground fault detection device operates by computing the total RMS voltage of all the phases, and comparing the total RMS voltage to a threshold to determine if a ground fault has occurred. | 04-15-2010 |
20100118451 | MULTIPLE-POLE CIRCUIT BREAKER WITH SHARED CURRENT SENSOR FOR ARCING FAULT DETECTION - A multi-pole circuit breaker for a power distribution system having multiple line conductors carrying AC currents that are out of phase with each other, and a common neutral conductor, comprises first and second current sensors, a ground fault detection circuit, and an arcing fault detection circuit. The first current sensor is adapted to be coupled to both of the line conductors and to the neutral conductor and produces a first output signal indicative of the resultant of the electrical currents flowing in the line and neutral conductors. The ground fault detection circuit receives the first output signal and produces a trip signal in response to the detection of a ground fault. The second current sensor comprises a coil wound on a toroidal core and is adapted to be coupled to both of the line conductors in a manner that the electrical currents in the line conductors flow in opposite directions inside the toroidal core, thus inducing in the coil a second output signal that is a function of the difference of the electrical currents in the line conductors. The arcing fault detection circuit receives the second output signal and includes a processor programmed to analyze the second output signal and produce a trip signal in response to the detection of an arcing fault. | 05-13-2010 |
20100328825 | SYSTEM AND METHOD FOR DETECTING A FAULT CONDITION - A system and method for detecting a fault condition by a relay is provided. The system includes means for detecting phase currents through three electrical phases, means for detecting a ground fault current, a processor configured to perform a current-based function based upon at least one of the phase currents and a filter. The processor is configured to perform current-based functions based on whether the filter is enabled or disabled. | 12-30-2010 |
20110075304 | SYSTEM AND METHOD FOR POLYPHASE GROUND-FAULT CIRCUIT-INTERRUPTERS - A ground-fault circuit-interrupter (GFCI) system is provided that provides reliable and timely tripping of faulted circuits while minimizing so-called “nuisance” tripping. The GFCI includes a voltage unbalance detection device coupled to the main bus circuit for detecting a voltage unbalance during a fault condition. A computer processor in communication with the voltage unbalance detection device is programmed to determine when an actual fault condition exists based on a state of the voltage unbalance and certain predetermined among the fault signal generated by a GFCI unit in the main bus circuit and the fault signals generated by GFCI units in individual feeder circuits. | 03-31-2011 |
20110085272 | Systems and Methods for Generator Ground Fault Protection - A generator winding-to-ground fault detection system is disclosed that includes a signal injection source in electrical communication with a winding of an electric power generator via an injection transformer. The winding may be coupled to ground via a winding-to-ground path and the signal generation source may generate an injection signal capable of being injected to the winding using the injection transformer. The disclosed system may further include a protection module in communication with the signal injection source and the electric power generator configured to receive the injection signal and a signal relating to the current through the winding-to-ground path, and to determine the occurrence of a winding-to-ground fault condition based at least in part on the injection signal and the signal relating to the current through the winding-to-ground path. | 04-14-2011 |
20110149448 | SHORT-CIRCUIT DISTANCE RELAY - A short-circuit distance relay is provided which has a high accuracy and an excellent reliability such that the relay can determine the fault phase based on impedance values measured by each phase, prevent misjudgment and unnecessary operation due to overreach without depending on the power system conditions, and operate even if multiple faults occur. An impedance calculation part ( | 06-23-2011 |
20110199707 | PHOTOVOLTAIC ARRAY GROUND FAULT DETECTION METHOD FOR UTILITY-SCALE GROUNDED SOLAR ELECTRIC POWER GENERATING SYSTEMS - Various methods and apparatus are described for a photovoltaic system. In an embodiment, a hybrid grounding circuit as well as a ground fault monitoring circuit are in the inverter circuitry with its switching devices that generate three-phase Alternating Current (AC) voltage. The three-phase AC voltage is supplied to a utility power grid interface transformer, where a primary-side common node of the Utility Power grid interface transformer is connected to Earth ground. Each inverter has 1) its own set of isolation contacts to connect as well as isolate this particular inverter from the utility grid interface transformer, and 2) control components in the ground fault monitoring circuit for controlling operation of the isolation contacts based off a presence of the ground fault detected by the ground fault monitor circuit for that inverter. The inverter circuit receives a DC voltage supplied from its own set of ungrounded Concentrated PhotoVoltaic modules. | 08-18-2011 |
20120140365 | DUAL-COMPARATOR RESTRICTED EARTH FAULT PROTECTION - An intelligent electronic device may provide restricted earth fault protection to components of an electrical power delivery system using both an amplitude comparator and a phase angle comparator configured to independently detect faults. The IED may include selection logic configured to select the output of one of the phase angle comparator and the amplitude comparator, to the exclusion of the other, based on system conditions. Accordingly, when system conditions are such that a phase angle comparator is better suited to detect a fault, selection logic may select the output of the phase angle comparator. Similarly, when system conditions are such that an amplitude comparator may better detect a fault, selection logic may select the output of the amplitude comparator. A protection system may further include an in-zone fault detector configured to detect in-zone faults. | 06-07-2012 |
20130329321 | POWER DISTRIBUTION SYSTEM INCORPORATING GROUND FAULT INTERRUPT PROTECTION - A power distribution system includes multiple uniform power distribution modules and multiple uniform mating connectors. A portion of the mating connectors are connected to the power distribution modules directly and the remainder are connected to the power distribution modules via a ground fault interrupt adapter. | 12-12-2013 |
20140071565 | METHOD AND PROTECTIVE DEVICE FOR DETECTING A SYMMETRICAL SHORT-CIRCUIT IN A MULTIPHASE ELECTRICAL POWER SUPPLY NETWORK - A first protective device monitors a first section of a power supply network for a symmetrical short-circuit and a second protective device monitors a second section for a symmetrical short-circuit. The second protective device is a reserve protective device, which emits a shut-off command to a power switch after a time lag when a symmetrical short-circuit in the first section is recognized. An oscillation recognition unit emits an oscillating signal which blocks the shutoff command if an oscillation in the power supply network has been recognized. External symmetrical short-circuits can be disconnected independently of an occurring oscillation, when the second protective device has recognized a symmetrical short-circuit in the first section, before the oscillation recognition unit recognizes an oscillation in the power supply network, the shut-off command is emitted independently of the presence of an oscillating signal if the lag time has elapsed. | 03-13-2014 |
20140153145 | METHOD AND SYSTEM FOR OPEN NEUTRAL PROTECTION CIRCUIT - An open neutral protection method and apparatus including a blocking diode arrangement to prevent connection of power in circuits when the power source has an open neutral. In particular, when more than one branch circuits are connected to a power supply with more than one hot power lines, blocking diodes prevent back feed currents from activating relays connecting the power source to the branch circuits when the power source has an open neutral. | 06-05-2014 |
20140168830 | THREE-PHASE GROUND FAULT CIRCUIT INTERRUPTER - A three-phase GFCI device is disclosed. The three-phase GFCI device may include contactors, a contactor control module configured to cause the contactors to close during normal operation of the GFCI device and open based on receiving a fault signal, a current detection module, a transient suppression module, a miswire detection module, a ground-fault test module, a ground load detection module, and a fail-safe module. In some examples, the GFCI device may include the stated modules in accordance with the UL 943C standard. | 06-19-2014 |
20140285930 | METHODS PROVIDING CONTROL FOR ELECTRO-PERMANENT MAGNETIC DEVICES AND RELATED ELECTRO-PERMANENT MAGNETIC DEVICES AND CONTROLLERS - Methods may be provided to control an electro-permanent magnetic device powered from an AC mains power source provided through first and second power lines of a controller, wherein a first switch is provided on the first power line between the AC mains power source and the electro-permanent magnetic device and a second switch is provided on the second power line between the AC main power source and the electro-permanent magnetic device. In particular, a sequence of switching pulses may be transmitted through the first and second switches to change a magnetic state of the electro-permanent magnetic device. Related controllers are also discussed. | 09-25-2014 |
20150124358 | FEEDER POWER SOURCE PROVIDING OPEN FEEDER DETECTION FOR A NETWORK PROTECTOR BY SHIFTED NEUTRAL - A feeder power source for a network power system includes a network transformer having a delta three-phase primary winding and a three-phase secondary winding; a three-phase primary feeder electrically connected to the delta three-phase primary winding; a three-phase secondary bus electrically connected to the three-phase secondary winding; and a three-phase electrical switching apparatus structured to open and close the three-phase primary feeder. A network protector includes a network relay and a three-phase circuit breaker structured to open and close the three-phase secondary bus. A first circuit is electrically connected between at least one phase of the three-phase primary feeder and ground, and is structured to unbalance shunt impedance to the three-phase primary feeder ground. A second circuit detects a shift in system neutral and detects that the three-phase primary feeder is opened by the three-phase electrical switching apparatus. | 05-07-2015 |
20150325998 | High-Voltage Direct Current Power Distribution and Fault Protection - A power distribution system including a high-voltage direct current unit (HVDCU) configured to receive an amount of high-frequency alternating current (AC) input power from a power source and convert the input power into high-voltage DC power, a negative voltage distribution rail and a positive voltage distribution rail that are together configured to supply the high-voltage DC power to at least one control unit (CU) electrically disposed between the negative voltage distribution rail and the positive voltage distribution rail and the CU being configured to convert the high-voltage DC power into output power compatible with at least one load and supply the output power to the loads associated with it. | 11-12-2015 |
20150326004 | ARC-FREE CAPACITOR TRIP DEVICE - An apparatus includes an energy storage module that receives power from an AC power source. The energy storage module is sized to store electrical energy received from the AC power source that is sufficient to open one or more contacts when the AC power source is not present. The contacts disconnect electrical power to a load and the electrical energy is stored in a DC energy storage device. A connection module connects the energy storage device in series with a trip contact, a trip circuit, and an auxiliary contact. The trip contact closes in response to a trip signal. The trip circuit disconnects the one or more contacts in response to being energized, and the auxiliary contact opens in response to opening of the one or more contacts and disconnects power to the trip circuit. A disconnect module periodically disconnects electrical power from the trip circuit and the auxiliary contact. | 11-12-2015 |
20150349512 | LEAKAGE CURRENT DETECTION INTERRUPTER WITH SELF-TESTING FUNCTION AND OVER-TEMPERATURE PROTECTION FUNCTION - A leakage current detection interrupter (LCDI) with self-testing function, which includes: a leakage current detection unit, including multiple current-carrying wires and at least one leakage current detection wire for detecting a leakage current of the current-carrying wires; a phase protection unit, coupled to at least one current-carrying wire on the input side of the multiple current-carrying wires, and coupled to at least one current-carrying wire on the output side of the multiple current-carrying wires via the leakage current detection unit, to form a current loop; wherein the phase protection unit can generate a control signal to disconnect the electrical coupling between the LCDI and the power source. By using a temperature controlled module, the leakage current detection unit and the phase protection unit, an LCDI with self-testing function is achieved. When there is a leakage current in the current-carrying wires, or the current-carrying wire is open, or the temperature of the electrical appliance exceeds a predefined range, or the leakage current detection wire is broken, the LCDI can disconnect its electrical coupling with the power source, ensuring the safety of the appliance and enhancing the quality of the electrical grid. | 12-03-2015 |
20160134101 | METHOD AND MEANS FOR COMPLEX, UNIVERSAL EARTH FAULT PROTECTION IN POWER HIGH AND MEDIUM VOLTAGE SYSTEM - A method and apparatus for earth fault in power high and/or medium voltage system may enhance a protection system for special technical task, which is to measure residual current, the invention is, that for earth fault protection in power system or a part of power system, for example, but not limited to, cable connectors, wherein residual current is determined indirectly by the calculation from the phase current values, obtained from the output signals of Rogowski-coil based current sensors. | 05-12-2016 |
361048000 | With more than three wires | 1 |
20120147508 | Three phase multi-generator ground fault circuit - A ground loop detection and prevention system includes multiple electric power generators driven by one or more rotational power sources. Each of the electrical generators has a set of generator windings with a neutral point. A transformer having a number of primary windings as well as a secondary winding is connected to the neutral points via the primary transformer windings. An interrupter device such as a GFCI is connected across the transformer's secondary winding, such that when a ground loop current occurs in any of the generator windings, the interrupter device detects the loop and stops the operation of the generators. | 06-14-2012 |