| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 361035000 | Transformer protection | 61 |
| 20080232006 | GIC reducer - A device for reducing Geomagnetically-Induced Currents (GIC) in transformer apparatus of an AC power system that comprises a resistor (R | 09-25-2008 |
| 20090027815 | Protective Device Having a Circuit Breaker, in Particular a Low-Voltage Circuit Breaker - A protective device is disclosed having a circuit breaker for an electrical connection between a transformer and a load, wherein an overcurrent device is arranged between the transformer and the load. The overcurrent device has first magnetoelectric transducers arranged at each phase conductor and the neutral conductor, wherein the overcurrent device uses the transducer currents to in each case establish the presence of a first ground-fault current, and wherein the circuit breaker has a switching device, which interrupts at least the phase conductors between the transformer and the load in the event of the presence of a first ground-fault current (unrestricted earth fault). In order to also be able to determine the ground fault current between the transformer and the circuit breaker, at least one embodiment of the invention proposes providing in each case second magnetoelectric transducers at each phase conductor, the neutral conductor and a star-point conductor which is connected to the star point, using the transducer currents of the second transducer in each case to determine the presence of a second ground-fault current (restricted earth fault), and forming a signal for disconnecting the transformer in the event of the presence of a second ground-fault current. | 01-29-2009 |
| 20090059447 | METHOD AND DEVICE FOR FAULT DETECTION IN AN N-WINDING THREE-PHASE POWER TRANSFORMER - A method and a device for fault detection in an n-winding, three-phase power transformer. For each of the windings (Wi) the three phase currents (I | 03-05-2009 |
| 20090091867 | Transformer Through-Fault Current Monitor - A device is provided for monitoring through-fault current in an electric transformer on an electrical power system. The device generally includes a magnitude calculator for calculating the magnitude of current (e.g., a root means square value of current or magnitude of a fundamental of current) based on the current through the electric transformer. A through-fault energy calculator is further provided which is coupled to the magnitude calculator for calculating a through-fault energy value based on the magnitude of current or the calculated current through the transformer. An accumulator is coupled to the through-fault energy calculator for accumulating a plurality of through-fault energy values, and an alarm coupled to the accumulator for indicating that the accumulated through-fault energy values exceed a selected threshold. | 04-09-2009 |
| 20090097173 | INCOMING CURRENT SUPPRESSION DEVICE - A control unit of an electric power supply system causes, responsive to a closing command signal, a switch corresponding to R phase to be thrown at a timing when a stationary magnetic flux and a residual magnetic flux of R phase are coincident with each other and then subsequently causes other switches corresponding to S phase and T phase to be thrown at a timing which is delayed from a zero point of an alternating voltage of R phase by a predetermined phase angle of 0-30 degrees, such that the difference of the stationary magnetic flux and the residual magnetic flux of each of S phase and T phase is minimum. Therefore, an exciting incoming current which flows into a three-phase transformer at a time of throwing a three-phase breaker provided with interpole capacitors can be suppressed. | 04-16-2009 |
| 20090279216 | Adjustable Rating for a Fault Interrupter and Load Break Switch - A fault interrupter and load break switch includes a trip assembly configured to automatically open a transformer circuit electrically coupled to stationary contacts of the switch upon the occurrence of a fault condition. The fault condition causes a Curie metal element electrically coupled to at least one of the stationary contacts to release a magnetic latch. The release causes a trip rotor of the trip assembly to rotate a rotor assembly. This rotation causes ends of a movable contact of the rotor assembly to electrically disengage the stationary contacts, thereby opening the circuit. The switch also includes a handle for manually opening and closing the electrical circuit in fault and non-fault conditions. Actuation of the handle coupled to the rotor assembly via a spring-loaded rotor causes the movable contact ends to selectively engage or disengage the stationary contacts. | 11-12-2009 |
| 20100085668 | PHASE-CONTROL SWITCHING APPARATUS AND SWITCHING CONTROL METHOD FOR PHASE-CONTROL SWITCHING APPARATUS - A residual-magnetic-flux calculating unit includes a voltage-change-rate detecting unit that detects a transformer-voltage change rate from a phase voltage between a breaker and a transformer, a residual-magnetic-flux detecting unit that detects a residual magnetic flux remaining on the transformer based on the phase voltage, and a breaker-switching-state identifying unit that detects a switching state of the breaker. The residual-magnetic-flux calculating unit recalculates the residual magnetic flux based on the transformer-voltage change rate and a predetermined threshold while the breaker is in an open state. | 04-08-2010 |
| 20100142102 | Low Force Low Oil Trip Mechanism - A circuit breaker for a transformer includes means for interrupting circuitry in the transformer upon a fault condition in the transformer (the “fault interruption means”). The circuit breaker also includes means for interrupting the circuitry when a level of dielectric fluid in a tank of the transformer is unacceptably low (the “low oil trip means”). The fault interruption means includes a magnet, metal element, and first actuator. Upon the fault condition, the magnet and metal element separate, moving the first actuator to cause the electrical circuitry to open. The low oil trip means includes a float, insulating rod, and second actuator. When the dielectric fluid level drops to an unacceptably low level, the float and insulating rod drop, moving the second actuator to cause the circuitry to open. The low oil trip means operates independently of the fault interruption means, opening the circuitry without separating the magnet and metal element. | 06-10-2010 |
| 20110090606 | Countermeasure for EMP-E3 induced currents - A countermeasure for mitigating Electromagnetic Pulse E3 (EMP-E3) induced currents flowing through the neutral of a star-connected three-phase power transformer without compromising its neutral end insulation performance. It comprises an external neutral-grounding device; a first linear resistor (R | 04-21-2011 |
| 20110128656 | OUTPUT SHORT CIRCUIT PROTECTION FOR ELECTRONIC TRANSFORMERS - An overcurrent protection control circuit for an electronic transformer includes a feedback current detection circuit, an averaging circuit and an overcurrent shutdown circuit. The feedback current detection circuit detects feedback current of an output of the electronic transformer. The averaging circuit determines an average of the feedback current detected by the feedback current detection circuit. The overcurrent shutdown circuit is configured to shutdown the output of the electronic transformer based on the average of the feedback current exceeding a predetermined threshold. The predetermined threshold indicates a short circuit condition. | 06-02-2011 |
| 20110181989 | TRANSFORMER INRUSH CURRENT SUPPRESSION APPARATUS - Inrush current suppression apparatus for suppressing a transformer inrush current including a transformer side voltage measurement unit which measures a voltage at a side of a transformer, a residual magnetic flux calculation unit which calculates three line-to-line residual magnetic fluxes, a power supply side voltage measurement unit which measures a voltage at a side of a power supply, a stable-state magnetic flux calculation unit which calculates three line-to-line stable-state magnetic fluxes, based on the voltage at the side of the power supply, a phase determination unit which determines a phase in which phases of the three line-to-line stable-state magnetic fluxes are respectively the same in polarity as phases of the three line-to-line residual magnetic fluxes, and a closing unit which closes the circuit breaker in the phase determined by the phase determination unit. | 07-28-2011 |
| 20110216450 | TRANSFORMER FAILURE ANALYSIS SYSTEM - A transformer failure analysis system using a programmable chip in conjunction with a shock response spectrum analysis method to distinguish inrush current and fault current of a transformer and to monitor the phase of an AC power source inputting to the transformer by means of a phase detector. When an inrush current occurs, the programmable chip provides a control signal to delay the phase of the AC power source being inputted into the transformer, thereby suppressing the occurrence of the inrush current. When a fault current occurs, the control signal cuts off the AC power source from the transformer until the operator has tested the whole circuit architecture to debug and correct circuit application and eliminated the internal fault. | 09-08-2011 |
| 20120008239 | TRANSFORMER MODULE WITH MULTIPLE PROTECTIONS - The transformer module of the invention includes an isolation transformer having a primary winding with a first tap and a secondary winding with a second tap. A protection circuit is electrically connected to the first tap and the second tap. The protection circuit includes at least one protective element. | 01-12-2012 |
| 20120026630 | Method and Apparatus For Use In Monitoring Operation of Electrical Switchgear - An instrument transformer includes a current transformer configured to be coupled to a load, and to generate an analog signal that is proportional to a current flowing through the load. The instrument transformer also includes a protection module and a digitizer module that is coupled to the current transformer. The digitizer module is configured to receive an input signal that is proportional to the analog signal and to convert the input signal to a digital signal. The digitizer module includes a synchronization module for generating at least one timing signal and a fiber optic interface module coupled to the protection module and to the synchronization module for transmitting the digital signal to the protection module. | 02-02-2012 |
| 20120162829 | STAND-ALONE CIRCUIT BREAKER ASSEMBLY AND ASSOCIATED METHOD OF USE - A stand-alone circuit breaker assembly that includes a housing having a plurality of openings, a plurality of first bushings mounted through the openings in the housing for receiving electrical power from the distribution transformer, at least one circuit breaker, each circuit breaker having a plurality of input terminals and a plurality of output terminals, wherein the at least one circuit breaker is located inside the housing, a plurality of first electrical connectors electrically connected in one-to-one correspondence between the plurality of first bushings and the plurality of input terminals, a plurality of second bushings mounted through the openings in the housing for providing electrical power through the at least one circuit breaker, and a plurality of second electrical connectors electrically connected in one-to-one correspondence between the plurality of second bushings and the plurality of output terminals. The stand-alone circuit breaker can be utilized with a distribution transformer. | 06-28-2012 |
| 20120236442 | INTELLIGENT CONTROLLER - Described herein is an intelligent controller for management and control of electrical distribution transformer either located within the transformer or outside the transformer, housed in a separate enclosure and mainly comprising: a. input terminals ( | 09-20-2012 |
| 20120293896 | INRUSH-CURRENT SUPPRESSING DEVICE AND INRUSH-CURRENT SUPPRESSING METHOD - An inrush-current suppressing device includes a residual-magnetic-flux calculation unit that obtains a residual magnetic flux generated within a three-phase transformer, an input magnetic-flux-error calculation unit that obtains a closing-phase input magnetic-flux error, a closing-order determination unit that determines a closing order of phases of a three-phase breaker, a target-closing-phase/time setting unit that sets a time from a reference point to a target closing phase of a first closing phase as a first target closing time, and sets a time obtained by adding up a time from the reference point to a target closing phase of a second closing phase and a delay time set to exclude a period in which a magnetic flux in the first closing phase possibly saturates as a second target closing time, and a closing control unit that generates and outputs a closing control signal to close each phase at the target closing time. | 11-22-2012 |
| 20130155553 | MAGNETIZING INRUSH CURRENT SUPPRESSION APPARATUS - According to one embodiment, there is provided a magnetizing inrush current suppression apparatus including a transformer-side voltage measuring unit measuring a single-phase voltage, a conversion unit converting the single-phase voltage to a three-phase voltage, a residual magnetic flux calculation unit calculating residual magnetic fluxes, a voltage measuring unit measuring a voltage on the power source side, a steady magnetic flux calculation unit calculating steady magnetic fluxes, a phase determination unit determining a phase in which polarities of the steady magnetic fluxes match polarities of the residual magnetic fluxes, and a closing unit closing the circuit breaker in the phase. | 06-20-2013 |
| 20130163125 | MAGNETIZING INRUSH CURRENT SUPPRESSION APPARATUS - According to one embodiment, there is provided a magnetizing inrush current suppression apparatus including an interrupting phase detection unit that detects a phase when the transformer that converts a three-phase alternating-current voltage to a single-phase alternating-current voltage is disconnected, a single-phase alternating-current voltage measurement unit that measures the single-phase alternating-current voltage on the power system side of the circuit breaker, and a closing unit that closes the circuit breaker in the detected phase, based on the measured single-phase alternating-current voltage. | 06-27-2013 |
| 20130182355 | CONNECTION DEVICE FOR TRANSFORMER SUBSTATION MODULES - The present invention relates to a transformer substation ( | 07-18-2013 |
| 20130308229 | Self-Testing Features of Sensing and Control Electronics for a Power Grid Protection System - Systems and method for detecting potentially harmful harmonic and direct current signals at a transformer are disclosed. One system includes a protection circuit electrically connected to a transformer neutral, the transformer electrically connected to a power grid, the protection circuit including a DC blocking component positioned between the transformer neutral and ground and one or more switches selectively actuated to form a path between the transformer neutral and ground in the event of unwanted DC current at the transformer neutral. The system also includes a control circuit electrically connected to the protection circuit and positioned to selectively actuate the switches based on observed conditions within the protection circuit. The system further includes a plurality of test connections disposed within the protection circuit and useable to test electrical properties of the protection circuit. | 11-21-2013 |
| 20140192443 | MAGNETIZING INRUSH CURRENT SUPPRESSION DEVICE - According to one embodiment, there is provided a magnetizing inrush current suppression device. A closing phase determination unit determines a phase position for suppressing the magnetizing inrush current among phase positions in which the prospective magnetic flux calculated by the prospective magnetic flux calculation unit and the residual magnetic flux calculated by the residual magnetic flux calculation unit coincide between the lines of the minimum residual magnetic flux determined by the minimum residual magnetic flux determination unit, as a closing phase position. A closing unit simultaneously closes the three phases of the circuit-breaker at the determined closing phase position. | 07-10-2014 |
| 20150043108 | SYSTEM, APPARATUS, AND METHOD FOR REDUCING INRUSH CURRENT IN A TRANSFORMER - A system for reducing inrush current in a three phase utility transformer upon energization of the transformer by an applied three phase voltage utilizes a pre-flux circuit for establishing residual flux levels in the core segments of the primary windings of the transformer which are near the prospective flux levels established in the core segments by the applied voltage. The pre-flux circuit includes a pre-fluxing capacitor which, after being charged to a predetermined voltage level, is discharged serially through two of the primary windings to establish the predetermined flux levels in the core segments of the two windings, and a reduced flux level in the core segment of the remaining primary winding. The transformer is energized at the instant of positively-referenced peak phase voltage to the third primary winding such that prospective and residual flux approach a near-equal level in all three core segments and inrush current is reduced. The method may be applied to the secondary or tertiary windings instead of the primary windings. Additionally, an alternative method allows application of the pre-fluxing circuit to a delta-connected set of transformer windings. | 02-12-2015 |
| 20150124356 | Blocker of geomagnetically induced currents (GIC) - A device for mitigating Geomagnetically Ground Induced Currents (GIC) flowing from the neutral of a star-connected three-phase power transformer to ground without compromising its basic insulation, operation or integrity. Resistor (R | 05-07-2015 |
| 20150124357 | EXCITATION INRUSH CURRENT SUPPRESSING APPARATUS AND EXCITATION INRUSH CURRENT SUPPRESSING METHOD - According to one embodiment, an excitation inrush current suppressing apparatus comprising: bus voltage measurement equipment which measures each phase voltage of the single-phase AC-side bus; transformer voltage measurement equipment which measures a single-phase-side voltage of the transformer; phase detector which detects a cutoff phase when opening the circuit breaker by monitoring each phase voltage measured by the bus voltage measurement equipment and the single-phase-side voltage measured by the transformer voltage measurement equipment, holds the detected cutoff phase, and outputs the same phase as the held cutoff phase; and close command output device which closes the circuit breaker by the same voltage phase as the cutoff phase output from the phase detector. | 05-07-2015 |
| 20150311697 | TRANSFORMER PROTECTION CIRCUIT AND METHOD - Systems and methods for protecting an electrical component in an alternating current system that includes a transformer are disclosed. In one aspect, a circuit includes a switch assembly connected between a transformer neutral of a transformer and a ground and having an open position and a closed position. In normal operation, the switch remains in a closed position. The circuit further includes a DC blocking component positioned in parallel with the switch assembly and connected between the transformer neutral and the ground, a voltage probe connected between the transformer neutral and ground and configured to monitor an instantaneous voltage level at the transformer neutral, and a control circuit configured to control the switch assembly, the control circuit including a sensor configured to actuate the switch assembly to an open position at least upon detection of a harmonic signal in at least one phase of the transformer or a predetermined threshold of DC or quasi DC current between the transformer neutral and the ground. | 10-29-2015 |
| 20150333509 | Protective Circuit for a Current Transformer and Current Transformer with a Protection Circuit - A protective circuit for a current transformer for preventing a secondary voltage on a secondary circuit of the current transformer from exceeding a secondary voltage threshold. A protective circuit input can be coupled to the secondary circuit of the current transformer such that the secondary voltage is applied to the protective circuit input. A control unit is connected to the protective circuit input. A switch unit is connected to the protective circuit input and is operatively connected to the control unit. The control unit is adapted to provide a control signal to the switch unit in response to the secondary voltage exceeding the secondary voltage threshold. The switch unit is adapted to short-circuit the protective circuit input in response to the control signal provided by the control unit. The switch unit is implemented as a semiconductor circuit. | 11-19-2015 |
| 20160126725 | ELECTROSTATIC DISCHARGE PROTECTION FOR A TRANSFORMER BALUN - A balun includes an input coil and an output coil with first and second outputs that vary during normal operation. The output coil has a center point connection that remains substantially constant during normal operation. An ESD circuit provides a low impedance path between the center point connection and chip ground when the voltage at the center point connection is above a first threshold voltage or below a second threshold voltage and isolates the center point connection from chip ground otherwise. Another ESD protection circuit provides ESD protection for other input or output terminals of the integrated circuit by selectively coupling the other input or output terminals to chip ground. Thus, a charge that builds up between one of the balun outputs and another terminal on the integrated circuit can be safely dissipated. | 05-05-2016 |
| 20160126738 | SURGE SUPPRESSION SYSTEM FOR MEDIUM AND HIGH VOLTAGE - A system of surge suppressor units is connected at multiple locations on a power transmission and distribution grid to provide grid level protection against various disturbances before such disturbances can reach or affect facility level equipment. The surge suppressor units effectively prevent major voltage and current spikes from impacting the grid. In addition, the surge suppressor units included various integration features which provide diagnostic and remote reporting capabilities required by most utility operations. As such, the surge suppressor units protect grid level components from major events such as natural geomagnetic disturbances (solar flares), extreme electrical events (lightning) and human-generated events (EMPs) and cascading failures on the power grid. | 05-05-2016 |
| 20160149396 | System For Protection Of Dry Type Transformers - A system for transient over voltage protection of a three-phase transformer. Two surge arresters are series connected across each winding of the transformer and the center point connection of the two surge arresters is electrically connected to a middle location of the winding. Three additional surge arresters are electrically connected from each phase to ground in the case of either a delta or Y connected transformer; and/or connected from a neutral point to ground in the case of a Y connected transformer. The system allows for all of the surge arresters to be packaged as an integrated surge arrester system to minimize induced transient over voltages and high stresses on the transformer winding due to internal resonances. | 05-26-2016 |
| 20160181786 | APPARATUS FOR MITIGATION OF ADVERSE EFFECTS OF GEOMAGNETICALLY INDUCED CURRENTS ON TRANSFORMERS | 06-23-2016 |
| 20160197469 | SYSTEMS AND METHODS FOR ACTUATING A TRANSFORMER NEUTRAL BLOCKING SYSTEM | 07-07-2016 |
| 20180026444 | SURGE SUPPRESSION SYSTEM FOR MEDIUM AND HIGH VOLTAGE | 01-25-2018 |
| 361036000 | With differential sensing means | 11 |
| 20090147412 | Transformer inrush current detector - A differential protection system for power transformers using Rogowski coils as current sensors can support an inrush current detection method based on sensing lows in the derivative of the sensed current. Effective detection of power transformer inrush conditions can enable blocking of a protection relay during inrush where the differential current may exceed a differential threshold value indicative of a fault without the presence of an actual fault. The outputs of the Rogowski coils, being proportional to the first time derivative of the sensed current, may be useful in the inrush detection method. Also, with reduced saturation concerns, the Rogowski coil protection system may employ a single slope response with increased sensitivity. A discrete time sampling technique for identifying low di/dt portions within the sensed current also may be useful in detecting power transformer inrush conditions. | 06-11-2009 |
| 20100039737 | MAGNETIZING INRUSH CURRENT SUPPRESSION DEVICE FOR TRANSFORMER AND CONTROL METHOD OF SAME - To provide a magnetizing inrush current suppression device for transformer and control method of same, which accurately calculates the residual magnetic flux when a transformer installed in a non-solidly earthed system, is interrupted by circuit breakers, and which enables suppression of the magnetizing inrush current occurring when three single-phase circuit breakers or single-phase circuit breakers are used for simultaneously supplying power to three phases of the transformer, without providing a circuit breaker with a resistor or other equipment to enlarge the circuit breaker. The device has steady-state magnetic flux calculation means for calculating the line-to-line steady-state magnetic flux of three-phase power supplies, residual magnetic flux calculation means for calculating the primary line-to-line residual magnetic flux of the transformer when the circuit breakers interrupt the transformer, phase detection means for detecting a phase at which the polarity and magnitude of the calculated steady-state magnetic flux and residual magnetic flux coincide for each line-to-line. Closing control means firstly causes only two-phase of the circuit breakers, which are connected with the line-to-line, to close at the detected phase, and then causes the remaining one-phase circuit breaker to close. | 02-18-2010 |
| 20100296205 | SYSTEM AND METHOD FOR PREVENTING, PROTECTING OLTC FROM FIRE AND/OR TRANSFORMER FROM EXPLOSION - The present invention relates to a system and method for preventing, protecting OLTC from fire and/or preventing, protecting and/or detecting explosion and/or resulting fire of electrical transformer ( | 11-25-2010 |
| 20110063761 | Transformer Differential Protection - 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. | 03-17-2011 |
| 20120019963 | DEVICE AND METHOD FOR ELIMINATING TRANSFORMER EXCITATION LOSSES - The invention is a device and method for eliminating core excitation losses in a distribution transformer when the transformer is not supplying power to loads. The invention consists of sensors, a control circuit, a user interface and a power contactor. The power contactor is connected on the line side of a transformer and is opened or closed automatically based on preprogrammed time or load criteria determined by the control circuit. In one operational mode and when the transformer is disconnected from the line, the control board generates low power pulses at the transformer load connection points in order to “search” for loads. If a load is detected, the transformer is reconnected by way of contactor closure. If the transformer load drops to zero, for a predetermined amount of time, the transformer is again disconnected and the pulsed load search is reestablished. | 01-26-2012 |
| 20120194949 | RELAY AND METHOD FOR PROTECTING TRANSFORMER, AND TRANSFORMER PROTECTING SYSTEM HAVING THE SAME - Disclosed are a relay and method for protecting a transformer, and a transformer protecting system having the same. In the present disclosure, whether a transformation ratio of a transformer has been correctly set or not may be determined based on an inner algorithm. If it is determined that the transformation ratio of the transformer has been incorrectly set, a user may be informed to reset the transformation ratio. This may prevent a malfunction of the relay when the system is operated, and may enhance a system stability. | 08-02-2012 |
| 20120236443 | INRUSH-CURRENT SUPPRESSING DEVICE AND INRUSH-CURRENT SUPPRESSING METHOD - An inrush-current suppressing device includes: a residual-magnetic-flux calculating unit that calculates a residual magnetic flux in a reference phase of a three-phase transformer while assuming a maximum magnetic flux level generated at a time of applying a rated voltage as 1 PU based on a measurement result of a transformer-voltage measuring unit before and after opening a three-phase circuit breaker; a stationary-magnetic-flux calculating unit that calculates a stationary magnetic flux in the reference phase of the three-phase transformer with reference to the maximum magnetic flux level obtained as the 1 PU based on a measurement result of a power-supply-voltage measuring unit, in response to a closing command to the three-phase circuit breaker; and a control unit that actuates a switch of the three-phase circuit breaker corresponding to the reference phase at a timing when the stationary magnetic flux and the residual magnetic flux in the reference phase match each other. | 09-20-2012 |
| 20130279048 | METHOD AND AN APPARATUS FOR SUPERVISION OF CURRENT TRANSFORMER IN A DIFFERENTIAL PROTECTION SYSTEM - A method and device are disclosed for supervising the operation of plural current transformers and for prevention of a malfunction, such as false tripping of power in an electrical system. Exemplary embodiments can include measuring current parameters (e.g., magnitude and phase angle) for each winding in current transformer (CT) sets. A negative sequence current can be calculated from measured phase currents and a fault condition determined. A phase angle difference parameter derived from phase measurements between two healthy CTs can be used as an additional condition parameter for reliable operation of equipment in the electrical system. | 10-24-2013 |
| 20130335864 | ELECTRONIC IGNITION SYSTEM FOR AN ENGINE OF A VEHICLE IN CASE OF FAILURE - An electronic system to discharge a transformer in case of a failure during a charging phase of the transformer. The system includes the transformer having a primary winding with a first terminal connected to a battery voltage and with a second terminal for generating a primary voltage signal, includes a switch serially connected to the primary winding and having a control terminal carrying a control voltage signal for opening or closing the switch and includes an electronic circuit. The electronic circuit further includes a current generator and a voltage clamping. | 12-19-2013 |
| 20140133054 | SAFETY APPARATUS AND MONITORING METHOD FOR A POWER TRANSFORMER, AND RELATED POWER TRANSFORMER - A safety apparatus and method for monitoring a liquid-filled power transformer wherein there is provided a sensing device associated with an electronic unit. The sensing device is suitable to be at least partially immersed into liquid and includes at least one movable part displaceable by movements of the liquid. The electronic unit detects signals indicative of an actual position of the movable part and is arranged to provide, based on the detected signals, data related to actual conditions of the transformer and/or of its cooling liquid. | 05-15-2014 |
| 20150349511 | POWER TRANSFORMER INRUSH CURRENT DETECTOR - Techniques for detecting an inrush current in a power transformer in are disclosed. For example, the presence of an inrush current on a current path in a power transformer may be determined by receiving a signal from a Rogowski coil positioned on a current path of a power transformer, the signal corresponding to a current flowing in the current path; sampling the received signal to produce samples of the received signal; and analyzing the samples of the received signal relative to at least two criteria to determine whether an inrush current is present. When an inrush current is present, operation of a protective relay is blocked. | 12-03-2015 |
| 361037000 | With temperature or pressure sensing means | 3 |
| 20090268356 | INPUT PROTECTION CIRCUIT - A voltage clamp protection circuit to protect against overvoltage conditions where there is insufficient current to blow a fuse. The voltage clamp protection circuit includes a voltage clamp and a thermal cutoff. The voltage clamp clamps any overvoltage to a clamping voltage. If an overvoltage condition persists for too long the voltage clamp dissipates a sufficient amount of heat to activate the thermal cutoff creating an open circuit that protects the rest of the circuit. The voltage clamp protection circuit may be used in combination with a variety of other protection circuits to provide increased protection. | 10-29-2009 |
| 20110002070 | Method of Protection From Over-Temperature and Corresponding Arrangement - A method of protecting from over-temperature a device associated with an electronic converter including a feedback path for regulating the output signal of said electronic converter may include providing a thermal sensitive component sensitive to the temperature of said device, and including said thermal sensitive component in said feedback path of said electronic converter, whereby said output signal of said electronic converter is reduced as a function of the temperature of said device as sensed by said thermal sensitive component. | 01-06-2011 |
| 20120200961 | ELECTRIC TRANSFORMER EXPLOSION PREVENTION DEVICE PROVIDED WITH A LIQUID DETECTOR - Device for preventing the explosion of an electrical transformer provided with a tank which is filled with a coolant liquid. The device includes a rupture element provided with tear areas and folding areas at breaking. The rupture element is able to break when the internal tank pressure exceeds a predetermined threshold. At least one flange for maintaining the rupture element, the said flange being arranged at side of the rupture element opposite the tank. The device comprises a liquid detector arranged at the side of the rupture element opposite the tank. | 08-09-2012 |
| 361038000 | Transformer with structurally combined protective device | 14 |
| 20090195942 | Effect of a loss of a reactive impedance of a transformer, when secondary windings of the transformer are short circuited. The Method and the Device for a reduction of a short circuit currents - Transformers, like series reactors, have the quality to limit the short-circuit currents to values determined by the transformer's impedance which consist of the resistance and the inductive reactance. | 08-06-2009 |
| 20110058289 | DEVICE FOR PREVENTING THE EXPLOSION OF AN ELEMENT OF AN ELECTRICAL TRANSFORMER - A device for preventing the explosion of an element of an electrical transformer provided with a tank containing a combustible cooling fluid, comprising a pressure release element for decompressing the tank, and a bag placed downstream of the pressure release element and configured to pass from a flat state to an inflated state upon the rupture of the pressure release element and for confining fluid. | 03-10-2011 |
| 20110188159 | METHOD AND DEVICE FOR SUPERVISING SECONDARY CIRCUIT OF INSTRUMENT TRANSFORMER IN POWER SYSTEM - A method and a protection IED for supervising a secondary circuit of an instrument transformer in a power system are disclosed. The instrument transformer is connected to a power system component. The method includes: detecting, by a protection IED which is connected to the secondary circuit of the instrument transformer and protects the power system component, disturbances in a signal from the instrument transformer; and determining whether a failure occurs in the secondary circuit of the instrument transformer, according to both a disturbance detection result from the protection IED and another disturbance detection result from at least one of other protection IEDs. The other protection IEDs include protection IEDs which are connected to other secondary circuits of the instrument transformer or to secondary circuits of another instrument transformer connected to the power system component, and protection IEDs which are connected to other instrument transformers connected to other power system components connected to the same busbar as the power system component is connected to. The secondary circuit supervision solutions provide more reliable and sensitive performance and need very small amount of information to be collected. | 08-04-2011 |
| 20110255199 | ARC FLASH HAZARD REDUCTION FOR TRANSFORMER SECONDARIES - Arc flash hazard reduction for transformer secondaries is provided. A current-limiting protection device such as a current-limiting fuse is located between the secondary windings of a transformer and switchgear having a main circuit breaker. Placing the current-limiting fuse between the secondary windings of the transformer and switchgear reduces arc flash hazard levels between the transformer and the switchgear. | 10-20-2011 |
| 20130027818 | TRANSFORMER INSTRUMENTATION AND METERING SYSTEM - A combined current transformer and metering system is described, having a securable case, two or more current transformers each having a core and secondary windings connected to a secondary circuit, wherein the transformers are mounted within the case. A wiring harness connects the secondary windings of the transformers with shorting current switches for short circuiting the secondary current circuit, and voltage switches for disconnecting a voltage, wherein both sets of switches are mounted on the case. A process of manufacturing the system is described, wherein the transformer cores are positioned within the case, the wiring is connected between the transformer cores and attachment hardware on an upper deck of the case, and insulation medium is inserted within the case. A base plate is described, having rails to hold the system and having a tab at one end, and apertures for a rod positionable between rails at a second end. | 01-31-2013 |
| 20150085404 | MAGNETIZING INRUSH CURRENT SUPPRESSING DEVICE - According to one embodiment, a magnetizing inrush current suppressing device includes, a first closing unit closes the circuit-breaker at the notable phase by the first phase determined by the first-phase determination unit, a second-phase determination unit determines a second phase at which the notable phase detected by the notable phase detection unit from the three-phase AC voltage measured by the power-supply-side voltage measurement unit becomes a zero point after the first phase determined by the first-phase determination unit, and a second closing unit closes the circuit-breaker at two phases other than the notable phase by the second phase determined by the second-phase determination unit. | 03-26-2015 |
| 20150131186 | SAFETY DEVICE FOR A POWER TRANSFORMER, AND RELATED POWER TRANSFORMER USING SUCH A SAFETY DEVICE - A safety device is disclosed for a power transformer containing a cooling liquid, and can include a shaped body having an inner chamber which is suitable to be at least partially immersed in cooling liquid and inside which gas can accumulate; a first floating element and a second floating element suitable to be at least partially immersed in and moved by cooling liquid; and a switch suitable to be actuated by the first floating element when the gas accumulated is such that the level of the cooling liquid in the inner chamber reaches a predetermined first threshold level and by the second floating element when the gas accumulated is such that the level of the cooling liquid in the inner chamber reaches a lower predetermined second threshold level, respectively. The first and second floating elements can be mounted on and move linearly relative to one or more corresponding guiding supports. | 05-14-2015 |
| 361040000 | With lightning arrester (e.g., spark gap) | 5 |
| 20100039738 | Inductive coupler for power line communications, having a member that provides an intended path for a flashover to discharge to ground - There is provided an inductive coupler for coupling a signal to a power line. The inductive coupler includes (a) a magnetic core having an aperture through which the power line is routed, (b) a winding wound around a portion of the magnetic core, where the signal is coupled between the winding and the power line via the magnetic core, and (c) an electrically conductive member on an exterior of the inductive coupler that provides a path to electrical ground for a flashover current. | 02-18-2010 |
| 20130135776 | CURRENT TRANSFORMER ARRANGEMENT - A current transformer configuration includes a primary part and a secondary part. The primary part is surrounded by a housing. The housing has a first conductive housing part and a second conductive housing part. An electrically insulating gap lies between the two conductive housing parts. The housing passes through the secondary part. The electrically insulating gap is bridged by a surge protection configuration. | 05-30-2013 |
| 20130170079 | ON-LOAD TAP CHANGER - The invention relates to an on-load tap changer for switching among winding taps of a step transformer without interruption. According to the invention, in each auxiliary current branch of the on-load tap changer, which operates with vacuum switching tubes as switching elements, additional switches are provided in series with the vacuum switching tubes and the respective winding tap. Said additional switches cause a complete galvanic isolation of the vacuum switching tubes in the auxiliary current branches in steady-state operation. | 07-04-2013 |
| 20130229733 | Lightening Protection Apparatus Using TN-C Common Ground - The present invention relates to a lightning protection apparatus using a TN-C common ground. A lightning protection apparatus using a TN-C common ground according to the present invention, which is disposed between a power source part and load facilities and is connected in series thereto in order to protect the power source part and the load facilities from lightning, includes: an input part surge protection circuit connecting to the power source part; an output part surge protection circuit connecting to the load facilities; a double winding transformer having a primary part and a secondary part, which connect to the input part surge protection circuit and the output part surge protection circuit, respectively; and common ground members connecting, respectively, to the input part surge protection circuit, the double winding transformer, the output part surge protection circuit, and the load facilities such that electric potentials applied to all of the former are the same as a reference electric potential. According to the present invention, malfunctioning of electromagnetic facilities can be prevented against overcurrent, grounding, electric leakage, and momentary short circuiting of the power source part or load facilities due to a lightning surge, to thereby save manpower. In addition, electric and electronic communication/information facilities, signal facilities, and control facilities can be efficiently operated without damage due to a lightning surge, to thereby improve economic efficiency. | 09-05-2013 |
| 20160133360 | INSULATING COVER FOR TRANSFORMER BRACKETS - The present disclosure provides insulating covers for mounting brackets used to secure arrester assemblies to transformers. The purpose of the insulating cover is to protect wildlife from electric shock, and to prevent power interruptions on high voltage distribution lines caused by the bridging of high voltage circuits by wildlife. | 05-12-2016 |
| 361041000 | With fuse | 2 |
| 20120281321 | DISCONNECTOR FOR DISTRIBUTION TRANSFORMERS WITH DIELECTRIC LIQUID - A disconnector for distribution transformers with dielectric liquid intended for comprehensive protection of a power grid or for protecting distribution transformers. The disconnector provides at least two cylindrical current-limiting fuses located inside a transformer tank. Each fuse is electrically connected with an external phase power supply through fixed contacts and moving contacts of the disconnector with the active part of the transformer. The disconnector has an additional auxiliary contact which is electrically connected to a switch connected to the active part of the transformer on a low voltage side of the transformer. | 11-08-2012 |
| 20180026437 | VEHICLE ACCESSORY POWER SWITCH | 01-25-2018 |
