Abstract: A virtual circuit breaker having an electrical relay and a control circuit, the control circuit including a load and wire protection (“OC”) detection unit, a microprocessor and a driver. The OC detection unit is configured to monitor a power flow and the electrical relay is effective to control it. The driver is effective to cause the relay to stop the power flow upon receipt of a deactivation command. The OC detection unit is effective to cause the driver to receive a deactivation command if the OC detection unit senses that a short circuit condition or an overload condition exists. The microprocessor of the control unit is configured so as to be capable of, at least, receiving input from the OC detection unit and sending output to the driver.

Abstract: A method of monitoring the grading margin between at least two time-current characteristics of Intelligent Electronic Devices (IEDA, IEDB) installed in an electrical power system, each Intelligent Electronic Device comprising a counting means, the grading margin comprising a safety margin set by a user, characterized in that it comprises, when a fault occurs which causes a fault current in the electrical power system, a step of providing a warning to the user when the safety margin is infringed upon.

Abstract: An overcurrent fault protection method includes detecting an overcurrent fault in a variable frequency electric power generation system having a first main generator connected to a first alternating current bus through a first generator line contactor, a second main generator connected to a second alternating current bus through a second generator line contactor and an auxiliary power generator connected to a plurality of bus tie contactors, through a third generator line contactor, and connected to at least one of the first and second alternating current buses through the plurality of bus tie contactors, in response to detecting the overcurrent fault, locking out one or more of the plurality of bus tie contactors and in response to a continued detection of the overcurrent fault, opening at least one of the first second and third generator line contactors.

Abstract: A DC supply unit includes a first current blocking device arranged to allow current to flow in a first direction through the first current blocking device, and to block current that flows in a second direction opposite the first direction. In this context, the first direction is the flow direction of current during normal operation of the DC supply network. The DC supply unit further includes a first switching unit arranged in anti-parallel connection with the first current blocking device, wherein the first switching unit is controllable in its on-state to selectively allow reverse current during normal operation of the DC supply network to flow through the first switching unit in the second direction so as to bypass the first current blocking device and in an off-state to block current in the second direction when a fault occurs in the DC supply network.

Abstract: An electrical circuit for driving a bus is described that includes a plurality of branches coupled to at least one signal line at a termination of the bus and a transmit data input configured to receive data that the electrical circuit drives across the bus. The electrical circuit also includes an over-current validation unit coupled to the transmit data input which is configured to validate an over-current condition detected at a first branch of the plurality of branches based at least in part on the data at the transmit data input. The electrical circuit also includes a branch control unit coupled to the over-current validation unit which is configured to disable at least one of the plurality of branches in response to a validated over-current condition at the first branch.

Abstract: An electrical circuit comprising a power supply, a load, first and second trunks disposed therebetween and control means adapted to control the electrical status of the first and second trunks, in which the control means comprises monitoring means adapted to monitor the current and/or voltage of the first and second trunks and to detect current and/or voltage events which are indicative of faults occurring thereon, and isolation means adapted to isolate the first or second trunk when the monitoring means detects a current and/or voltage event which is indicative of a fault occurring thereon, in which the first and second trunks are electrically connected and arranged in parallel such that the power supplied to the load is distributed substantially equally between them, and in which the control means comprises compensation means adapted to prevent the isolation means from isolating one of said first or second trunks when a current and/or voltage event which is indicative of a fault occurs thereon which is caus

Abstract: A current differential relay apparatus includes a ratio-differential-characteristic determining unit determining an operation in a ratio differential characteristic based on an operation level Id and a suppression level Ir, a first-current-range determining unit determining that it is activated when Id>a1Ir+b1 is satisfied, a second-current-range determining unit determining that it is activated when Id>a2Ir+b2 is satisfied with relationships a1?a2 and b1?b2 being satisfied where a1, a2, b1 and b2 are real numbers, and an AND operator, a reset unit, and a flip flop which determine that it is an operation in a ratio differential characteristic when both first and second current ranges are activated, and which continue the operation until an operation in the first range is reset.

Abstract: A safety shut-off system and method for eliminating power to a load in the event of smoke detection. The system may comprise a device located at the appliance for detecting a signal from a smoke detector, and cutting power to the appliance only when the appliance is in use. The device may be synchronized with any standard smoke alarm signal to reduce the number of false positive shut-offs. The system may also comprise a smoke alarm hard-wired to a circuit breaker, for shutting off power to all appliances on a particular breaker upon receipt of a signal from the smoke alarm, and only when the appliances on the breaker are in use. The system may also have the ability to shut off one breaker, multiple breakers, or all breakers at different time increments to actively prevent and reduce the damages caused by fires.

Abstract: A fault current limiter (FCL) for limiting a fault current in a power line during a fault condition. The FCL includes a magnetic coupling circuit for monitoring current in the power line through magnetic coupling; a sensing circuit for sensing the current in the power line and providing a signal indicative of the sensed current; a control circuit receiving the signal indicative of the sensed current in the power line and determining whether the sensed current indicates that the fault condition exists; and high and low impedance paths that are connected in parallel. The high impedance path includes a discharging impedance circuit for limiting the fault current. The low impedance path includes a reactor circuit and a switching unit having an ON state for conducting current through the low impedance path and an OFF state for conducting current through the high impedance path.

Abstract: A system for combining multiple direct current power sources is provided. The system is operable to combine multiple feeds from an array of power generating elements, such as solar panel arrays and combine the feeds into a single voltage output. The system includes a current monitoring assembly operable to monitor the current from each input to evaluate whether there is a malfunction or other problem associated with a particular output. The system also includes a noise detection assembly for monitoring the current to evaluate whether there is a malfunction or other problem. An alarm or other signal can be provided to inform the operator of which power generating element in the array need to be analyzed in response to the output from the current monitoring assembly and the noise detection assembly.

Abstract: Power modules and related methods are providing configured to supply power from a power source to a power consuming unit. The power module configured to disconnect power in the power module in case of excess currents through the circuit breakers.

Abstract: To prevent demagnetization of a permanent magnet synchronous rotating machine, a rotating machine control device according to the present invention is a rotating machine control device comprising: a power converter having a switch part on each of a positive side and a negative side for each phase; and short circuit detection unit for detecting a short circuit of the switch part, wherein a command to turn on positive-side switches and negative-side switches of a plurality of phases of the switch part is issued in the case where the short circuit detection unit detects the short circuit.

Abstract: An apparatus includes at least one Rogowski coil and a processor. The at least one Rogowski coil is positioned within an electrical power distribution network to detect a first traveling wave current caused by a fault on an electrical power transmission line of the network, generate a first signal indicative of detection of the first traveling wave, detect a second traveling wave current caused by the fault on the transmission line, and generate a second signal indicative of detection of the second traveling wave. The processor is adapted to receive the first signal and the second signal and to determine, based on the first signal and the second signal, where on the transmission line the fault occurred.

Abstract: Magnetic field current sensing devices, systems and methods are disclosed. In an embodiment, a current sensor includes a semiconductor die; an isolation layer disposed on the semiconductor die; at least one anchor pad disposed on the isolation layer; a current input and a current output galvanically isolated from the semiconductor die; at least one bond wire coupled to the current input and the current output, a longitudinal portion of the at least one bond wire disposed between the current input and the current output being stitched to the at least one anchor pad; and at least one sensor element arranged to sense a magnetic field induced by a current flowing in the at least one bond wire.

Abstract: Provided is a short-circuit isolator capable of earlier detection of recovery from short circuit of a disconnected line and reconnecting the line.

Abstract: Active inrush current control includes activating a load, the activating causing inrush current to flow, switching a semiconductor switching device to a current limiting state in response to the inrush current flow, the current limiting state being one of at least three states of the semiconductor switching device and the current limiting state dissipating the inrush current, and switching the semiconductor device to a full current flow state in response to the dissipating, the full current flow state not inhibiting current flow.

Abstract: A system and method for operating a semi-conductor based circuit breaker as a transient current limiter includes a semi-conductor switch that operates in a linear mode during a transient event and thereby reduces the transient current passing through the switch.

Abstract: A fault current limiter (FCL) for limiting a fault current in a power line during a fault condition. The FCL includes a magnetic coupling circuit for monitoring current in the power line through magnetic coupling; a sensing circuit for sensing the current in the power line and providing a signal indicative of the sensed current; a control circuit receiving the signal indicative of the sensed current in the power line and determining whether the sensed current indicates that the fault condition exists; and high and low impedance paths that are connected in parallel. The high impedance path includes a discharging impedance circuit for limiting the fault current. The low impedance path includes a reactor circuit and a switching unit having an ON state for conducting current through the low impedance path and an OFF state for conducting current through the high impedance path.

Abstract: A system and method for protecting a power system. A generator is tripped in response to identifying a current on the generator that is greater than a first current threshold for a first time delay. The generator is also tripped in response to identifying the current on the generator that is greater than a second current threshold for a second time delay. The first current threshold is larger than the second current threshold and the first time delay is shorter than the second time delay.

Abstract: Transformer differential protection is provided by measuring a plurality of currents corresponding to a first set of windings and a second set of windings of a transformer, and compensating the currents based on their respective flows through either the first set of windings or the second set of windings. The compensated currents may be intentionally augmented to compensate for magnetizing inrush and/or stationary overexcitation conditions associated with the transformer. Augmentation based on stationary overexcitation, for example, may be based on either harmonic restraint or an addition of a V/Hz ratio to a restraining signal. A complex current ratio is calculated corresponding to the plurality of compensated currents. The complex current ratio may be based on a two-terminal equivalent power apparatus. Then, an alpha plane analysis is applied to the complex current ratio. Based on the alpha plane analysis, a power apparatus that includes the transformer is selectively tripped.

Abstract: Disclosed is a unit rack for power storage having a plurality of cell modules which are series- or parallel-connected with each other; a housing for accommodating the cell modules; a receiving part of a circuit breaker, formed or installed in the housing, and having a ground clearance higher than the highest ground clearance of the cell modules; a circuit breaker received in the receiving part and connected between the connection lines; and a receiving part cover for closing the receiving part of the circuit breaker.

Abstract: A circuit interrupter apparatus includes circuit interrupter and a device. The circuit interrupter includes separable contacts, an operating mechanism structured to open and close the separable contacts, and a trip mechanism cooperating with the operating mechanism to trip open the separable contacts. The trip mechanism includes a zone selective interlocking input and a zone selective interlocking output. The device includes a first input electrically interconnected with the zone selective interlocking input, a second input electrically interconnected with the zone selective interlocking output, and an indicator circuit structured to indicate that the zone selective interlocking input occurred at the first input or that the zone selective interlocking output occurred at the second input.

Abstract: A power distribution system for a dynamically positioned vessel may include: a plurality of busses including a first bus to which a load is connectable; a plurality of switches including a first switch and a second switch, wherein the plurality of busses is connected via the switches in a interjacent manner to form a ring, the first bus is connected between the first switch and the second switch, and the power distribution system is configured to concurrently open the first switch and second switches, if a first current flowing via the first switch towards the first bus is above a predetermined current threshold for longer than a predetermined time and a second current flowing via the second switch towards the first bus is above the predetermined current threshold for longer than the predetermined time, thereby disconnecting the first bus from the ring while all other buses remain connected together.

Abstract: A grounding apparatus includes a current detector configured to detect a current flowing in the ground line, a fuse inserted in series in a part of the around line and configured to melt when the current flowing in the ground line exceeds the first protection setting value, not destroying the current detector, and then exceeds the first protection setting value, causing a complete grounding fault, and a determination device configured to give an open command to the circuit breaker when the current detected by the current detector exceeds the first protection setting value of the circuit breaker.

Abstract: A current differential relay apparatus includes a ratio-differential-characteristic determining unit determining an operation in a ratio differential characteristic based on an operation level Id and a suppression level Ir, a first-current-range determining unit determining that it is activated when Id>a1Ir+b1 is satisfied, a second-current-range determining unit determining that it is activated when Id>a2Ir+b2 is satisfied with relationships a1?a2 and b1?b2 being satisfied where a1, a2, b1 and b2 are real numbers, and an AND operator, a reset unit, and a flip flop which determine that it is an operation in a ratio differential characteristic when both first and second current ranges are activated, and which continue the operation until an operation in the first range is reset.

Abstract: A battery is protected without realizing the state of every vehicle element connected to the battery or the battery input/output current. A current limit value setting unit sets a current limit value for limiting the battery input/output current in accordance with state of the battery. A limiting current ratio calculation unit calculates a ratio of the current limit value set by the current limit value setting unit to a detected battery current value. A request limit coefficient calculation unit calculates a limit coefficient for limiting a request value for driving respective vehicle components based on the ratio calculated by the limiting current ratio calculation unit. In addition, a final request value calculation unit calculates as a final request value for the respective vehicle components, respective multiplication values resulting from multiplying the respective request values for the respective components by the limit coefficient calculated by the request limit coefficient calculation unit.

Abstract: The apparatus for preventing a secondary accident by short of sensing lines in a high voltage battery using a fuse, includes: a plurality of battery modules provided with a plurality of battery cells; a battery pack including a plurality of battery modules; a battery management system (BMS) for monitoring and controlling voltage of each battery cell provided in each battery pack to monitor the status of each battery cell; sensing lines connected between the battery module and the battery management system to sense voltage of each battery cell of each battery pack; and a passive safety device to be connected in series to a terminal of each battery cell provided in each battery pack when a short accident that a closed circuit is formed in the sensing line occurs.

Abstract: A power distribution and communication system includes nodes connected by power lines and communication links. The system receives power from one or more power sources. Each node contains at least one power port, data port and load port. Associated with each power port and load port is a port monitor for measuring current flowing into or out of the port and the voltage difference between the port outlet and ground, which measurements are passed to a processing element. The processing element and monitor analyze measured values to detect fault conditions. Upon fault condition detection, the port is disabled by opening a switch, disconnecting the port from the system voltage. The processing element receives power directly from the power line, thus receiving power from a live power line even if the associated power port is disabled allowing the processing element to enable a disabled node following a failure.

Abstract: A safety shut-off system and method for eliminating power to a load in the event of smoke detection. The system may comprise a device located at the appliance for detecting a signal from a smoke detector, and cutting power to the appliance only when the appliance is in use. The device may be synchronized with any standard smoke alarm signal to reduce the number of false positive shut-offs. The system may also comprise a smoke alarm hard-wired to a circuit breaker, for shutting off power to all appliances on a particular breaker upon receipt of a signal from the smoke alarm, and only when the appliances on the breaker are in use. The system may also have the ability to shut off one breaker, multiple breakers, or all breakers at different time increments to actively prevent and reduce the damages caused by fires.

Abstract: A plant for transmitting electric power includes a high voltage DC line, a DC breaker connected in series therewith and configured to break a fault current upon occurrence of a fault, a device configured to detect occurrence of a fault current, a control unit configured to control the DC breaker for protecting equipment connected to the DC line upon occurrence of the fault current and a device configured to dissipate energy stored in a faulty current path of the DC line between the location and the device's upon occurrence of the fault to the moment of the control of the DC breaker. The energy dissipating device includes a series connection of an energy consuming braking resistor and a free-wheeling rectifying member connected between ground and the DC line to conduct current while forming a free-wheeling path therethrough upon the control of the DC breaker upon occurrence of the fault.

Abstract: A method to protect a circuit having at least a first circuit breaker, and a second circuit breaker arranged upstream of said first circuit breaker, said first circuit breaker having configuration settings selectable between a normal mode and an alternate mode, the alternate mode setting including a reduced energy let-thru (RELT) mode setting having a RELT mode trip time delay. The method including determining if said first circuit breaker is configured in said RELT mode, determining a. dynamic delay time for opening said second circuit breaker, wherein said dynamic delay time is based at least in part on said RELT mode trip time delay of said first circuit breaker, and triggering said second circuit breaker to open after said dynamic delay time has elapsed.

Abstract: A circuit interrupter apparatus includes circuit interrupter and a device. The circuit interrupter includes separable contacts, an operating mechanism structured to open and close the separable contacts, and a trip mechanism cooperating with the operating mechanism to trip open the separable contacts. The trip mechanism includes a zone selective interlocking input and a zone selective interlocking output. The device includes a first input electrically interconnected with the zone selective interlocking input, a second input electrically interconnected with the zone selective interlocking output, and an indicator circuit structured to indicate that the zone selective interlocking input occurred at the first input or that the zone selective interlocking output occurred at the second input.

Abstract: System of current protection of a primary electrical distribution box supplied by at least one electrical energy generator and delivering electrical energy to at least one load and/or to at least one secondary distribution box, comprising a line contactor for each generator arranged between the primary electrical distribution box and said generator, the primary electrical distribution box comprising an electrically conductive frame. The system of protection comprises an electrical connection member capable of electrically coupling the frame of the box to an external metal structure coupled to the earth, a current sensor capable of measuring a current flowing through said electrical connection member, and control means capable of controlling the line contactors so as to electrically decouple at least one generator from the primary electrical distribution box if a current flowing through said electrical connection member is detected.

Abstract: A power supply system having a spot network is disclosed. The spot network may include first and second power output lines, and first and second accessory power circuits connected in parallel to the first and the second power output lines, respectively. Each of the first and the second accessory power circuits may have a transformer and a circuit breaker connected together to protect the spot network by coordinating impedance of the transformer with trip characteristics of the circuit breaker.

Abstract: Power modules and related methods are providing configured to supply power from a power source to a power consuming unit. The power module includes circuit breaking means configured to disconnect power feeding means in the power module in case of excess currents through the circuit breaking means.

Abstract: A circuit interrupter apparatus includes circuit interrupter and a device. The circuit interrupter includes separable contacts, an operating mechanism structured to open and close the separable contacts, and a trip mechanism cooperating with the operating mechanism to trip open the separable contacts. The trip mechanism includes a zone selective interlocking input and a zone selective interlocking output. The device includes a first input electrically interconnected with the zone selective interlocking input, a second input electrically interconnected with the zone selective interlocking output, and an indicator circuit structured to indicate that the zone selective interlocking input occurred at the first input or that the zone selective interlocking output occurred at the second input.

Abstract: A differential protection system has a differential protection device at each end of a line section of an electrical power transmission line, such that it can selectively identify and safely disconnect even high-impedance faults on the monitored line section.

Abstract: A power distribution system distributes power to each section of a building via a main line which is wired to pass through each section of the building. The power distribution system is equipped with a plurality of sensors which are provided at each section of the building and which monitor the current value of the main line in the respective sections.

Abstract: A low voltage DC power supply is provided in a load center for distributing electrical power from electrical power utility lines to multiple branch circuits via a load center bus connected to the utility lines, each of the branch circuits having a circuit breaker coupled to a processor that is shared by multiple circuit breakers in the load center. The low voltage DC power supply includes a switch mode low voltage power supply connected to the processor for supplying the processor with a DC power input, and a line-derived power supply and a fault-derived power supply coupled between the utility and the switch mode power supply for supplying DC inputs to the switch mode power supply.

Abstract: An electrical switching apparatus is for another apparatus including a number of insulators, a number of temperature sensors operatively associated with the number of insulators, and a number of conductors operatively associated with the number of insulators. The electrical switching apparatus includes a number of separable contacts, an operating mechanism structured to open and close the separable contacts, a number of sensors structured to sense a number of currents flowing through the separable contacts and through the conductors, a processor structured to input the sensed currents from the sensors, and an output. The processor calculates at least one of: (a) a thermal age of the other apparatus from a number of sensed temperatures from the temperature sensors, and (b) the thermal age of the other apparatus from the sensed currents. The output includes the thermal age of the other apparatus.

Abstract: A compressor monitoring system includes current and voltage monitors, current and voltage averaging modules, a control module, and a switch. The current monitor measures a current drawn by a motor of a compressor. The current averaging module generates first and second average current values based on the current measured by the current monitor. The voltage monitor measures a utility power voltage. The voltage averaging module generates first and second average voltage values based on the voltage measured by the voltage monitor. The control module selectively generates a fault signal when a first ratio is greater than a first predetermined threshold and a second ratio is less than a second predetermined threshold. The first ratio is based on the first and second average current values. The second ratio is based on the first and second average voltage values. The switch deactivates the motor when the fault signal is generated.

Abstract: A system and method for operating a semi-conductor based circuit breaker as a transient current limiter includes a semi-conductor switch that operates in a linear mode during a transient event and thereby reduces the transient current passing through the switch.

Abstract: A current differential relay device is described. The device has two transmission parts provided in parallel and communicating with an other end of a power transmission line through two transmission paths and transmitting and receiving a quantity data of electricity of each of the terminals to and from an other end in the form of the digital data obtained through analog/digital conversion. Two current differential operation parts are connected to each of the two transmission parts and perform a current differential operation independently for each of the transmission paths by using the digital data of the quantity data of electricity of the one end of the power transmission line and of the other end of the power transmission line. A signal generation part generates a trip signal from the current differential operation result of the two current differential operation parts.

Abstract: An overcurrent cutoff device includes a heat generating unit located in series with a path leading from a battery B for a vehicle to a motor via a wire, and a heat sensing unit with characteristics varying with the temperature supplied from the heat generating unit. The overcurrent cutoff device cuts off overcurrent by activating a switching element, based on a signal in accordance with the temperature obtained from the heat sensing unit. The overcurrent cutoff device includes an overcurrent detecting element in which the heat generating unit and the heat sensing unit are integrally covered with a molded resin section.

Abstract: A method and apparatus is disclosed for providing protection against arc flash during maintenance on a low voltage power circuit including a circuit breaker having a specified trip function for responding to a fault is provided. The specified trip function is overridden with a maintenance trip function that results in reduced arc energy in the fault during a trip over arc energy during a trip with the specified trip function. The specified trip function is restored following maintenance.

Abstract: An electrical switching apparatus includes a plurality of poles each having a Rogowski coil and a conductor passing through an opening thereof, and a processor circuit including a sensor circuit including a plurality of inputs each electrically interconnected with an output of the Rogowski coil of a corresponding pole. The sensor circuit further includes a number of outputs having values each corresponding to current flowing through the conductor, a memory including for each corresponding pole an offset value and a gain correction factor for the sensor circuit, and a gain correction factor for the Rogowski coil, a number of routines, and a processor cooperating with the sensor circuit and the routines to provide for each pole a corrected current value as a function of a corresponding one of the values, the sensor circuit offset value and gain correction factor, and the Rogowski coil gain correction factor.

Abstract: A direct current feeder protection system includes six conductors, four current sensors sensing four currents flowing in four of the conductors, four circuit interrupters interrupting currents flowing in the four conductors, and a processor cooperating with the current sensors to input four sensed currents, and to output a number of commands to the circuit interrupters. The processor includes a routine detecting a number of: a directional current fault of the sensed currents, a differential current fault of the sensed first and third currents or the sensed second and fourth currents, and a residual current fault of the sensed first and second currents or the sensed third and fourth currents, and to responsively output the commands. The first, fifth and third conductors are electrically connected in series with two of the circuit interrupters, and the second, sixth and fourth conductors are electrically connected in series with the other circuit interrupters.

Abstract: In a motor control device that drives a plurality of motors with one DC power supply, detection of a short circuit fault occurring in the motors is realized with an inexpensive configuration. In order to drive the plurality of motors (105, 106), a current detection resistor (404, 405) is arranged between a connection point on positive terminal sides of a plurality of electric power converters (401, 402) connected in parallel to a DC power supply (403) and a positive terminal of the DC power supply, or also between a connection point on negative terminal sides of the plurality of electric power converters and a negative terminal (ground) of the DC power supply, to thereby detect the short circuit fault based on a voltage of the current detection resistor.

Abstract: According to one aspect of the invention, a plug-in module is provided for installing in a power distribution assembly. In one embodiment, the plug-in module may include an overcurrent protection device, a power cable, which may include a first end coupled to the overcurrent protection device, and a second end coupled to the first end, one or more receptacle outlets attached to the second end and electrical contacts coupled to the overcurrent protection device and configured to couple the plug-in module to a plurality of stationary electrical conductors of the power distribution assembly.

Abstract: Embodiments of a multi-level power hierarchy are described. This power hierarchy contains a higher level, which includes a first sub-circuit, and a lower level, which includes a second sub-circuit and a third sub-circuit. Moreover, the second sub-circuit and the third sub-circuit are included in branches in the power hierarchy and are separately electrically coupled to the first sub-circuit. A given sub-circuit in a given level includes programmable power protection which is configured to protect sub-circuits at higher levels of the power hierarchy from power variations associated with changes in load on branches at lower levels of the power hierarchy, thereby providing failure isolation in the power hierarchy.