Class / Patent application number | Description | Number of patent applications / Date published |
324510000 | Of electrically operated apparatus (power tool, appliance, machine, etc.) | 27 |
20090085575 | Testing method for a ground fault detector - A testing system for a ground fault detection system of an electrical system of a machine is disclosed. The testing system has a low voltage power source, the low voltage power source capable of operation that is independent from a high voltage power source of the machine. The testing system also has a variable current source that is permanently connected to a positive voltage bus or to a negative voltage bus of the electrical system of the machine, where the machine operates self-sufficiently. The testing system also has a controller connected to the variable current source. The testing system also has an input device, where the input device is connected to the controller. | 04-02-2009 |
20090085576 | APPARATUS, SYSTEM AND METHODS FOR GROUND CURRENT DETECTION - Various systems, methods and apparatus are described for detecting an excessive or faulty ground current in a conductive wire or electronic device. A ground current detector is coupled to a known earth ground to determine whether other ground lines are carrying excessive, faulty and/or leaking currents. If these types of unsafe conditions are detected, then a user can take appropriate action to locate and correct these problems. | 04-02-2009 |
20090219030 | Methods and Systems for Detecting Rotor Field Ground Faults In Rotating Machinery - Embodiments of the invention can include methods and systems for detecting rotor field ground faults in rotating machinery. In one embodiment, a system can include a rotor of the rotating machine comprising a plurality of field windings substantially disposed therein and a stator of the rotating machine comprising a plurality of stator windings substantially disposed therein, with an air gap existing between the rotor and the stator. The system can include a high-impedance grounding circuit at least temporarily connected between the rotor and a ground. Additionally, the system can include an air gap flux probe positioned at least temporarily between the rotor and the stator for measuring a magnetic flux density generated in the air gap during operation of the rotating machine. Finally, the system can further include an analyzer in electrical communication with the air gap flux probe for receiving an output of the air gap flux probe. | 09-03-2009 |
20100244849 | ELECTRIC VEHICLE WITH GROUND FAULT DETECTING SYSTEM - An electric vehicle incorporates a ground fault detecting system for preventing a ground fault detector from detecting a ground fault in error. First and second ground fault detectors are associated respectively with first and second ungrounded power supplies which generate respective different voltages. Since the first and second ground fault detectors are activated in different periods, the ground fault detecting system prevents a ground fault from being detected in error. | 09-30-2010 |
20100244850 | ELECTRIC VEHICLE WITH GROUND FAULT DETECTING SYSTEM - An electric vehicle incorporates a ground fault detecting system and has first and second ungrounded power supplies. The ground fault detecting system includes a first insulation resistance detector for detecting a first insulation resistance of the first ungrounded power supply with respect to a grounded region of the electric vehicle, and a second insulation resistance detector for detecting a second insulation resistance of the second ungrounded power supply with respect to the grounded region. The first insulation resistance detector and the second insulation resistance detector detect the first insulation resistance and the second insulation resistance at different times, respectively. | 09-30-2010 |
20100315092 | FAULT PREDICTION IN ELECTRONIC TRANSMISSION NETWORKS - A system and a method for measuring leakage current in an electrical transmission network. The system contains a plurality of electric current measurement devices distributed along the electrical transmission network and at least one central controller. The current measurement devices measure the electric current substantially continuously or repeatedly and report to the central controller. The central controller performs analysis of the measurements of the electric current along the transmission network and calculates the leakage current. | 12-16-2010 |
20110175619 | METHOD AND APPARATUS FOR MONITORING ELECTRICAL GROUND ISOLATION IN A POWERTRAIN SYSTEM - A method for monitoring operation of a vehicle including a high voltage electrical system including an electrical energy storage device electrically connected to switching circuits of an inverter device via a high voltage bus, the inverter device configured to transfer electric power to an electric machine via activation of a plurality of switch devices, includes monitoring electrical ground isolation of the high voltage electrical system during ongoing operation of the vehicle, detecting an electrical ground isolation fault in the high voltage electrical system, and detecting a location of the electrical ground isolation fault associated with at least one of the electrical energy storage device, the high voltage bus, the inverter device, and the electric machine subsequent to a vehicle key-off event. | 07-21-2011 |
20110221448 | Apparatuses and Methods for Testing Welding Apparatuses - A testing apparatus for testing a welding apparatus is disclosed. The testing apparatus comprises a receptacle, a fault indicator, and a power supply, wherein: the receptacle comprises a grounding socket and a plurality of power sockets; the power supply is electrically coupled to the grounding socket, the fault indicator, and at least one of the plurality of power sockets; and when a plug of the welding apparatus is matingly coupled to the receptacle, the fault indicator indicates whether an electrical resistance between a grounding prong of the plug and at least one of a plurality of power prongs of the plug is below a predetermined threshold. | 09-15-2011 |
20120229144 | ELECTRIC ROTATING MACHINE - This invention aims to provide an electric rotating machine which is free from the procedure of selecting different preset neutral current values for different types of machines, and which can detect a ground fault in a phase coil of the armature winding without suffering any erroneous operation. An electric rotating machine having an armature winding including three phase coils, which has been provided to attain the object of this invention, comprises a grounding resistor connected at a neutral of the armature winding, and current measuring apparatuses furnished for at least two phase coils, wherein phase currents through the phase coils are compared with each other, and the detection of a coil ground fault is determined when harmonic components of the phase currents differ from each other. | 09-13-2012 |
20130021038 | INSULATION FAILURE DIAGNOSIS APPARATUS AND METHOD OF DIAGNOSING INSULATION FAILURE - An insulation failure diagnosis apparatus is provided which diagnoses presence/absence of insulation failure between a body of a vehicle and a connection path to a power supply for a traction unit. The apparatus includes a power converter circuit connected to the power supply and supplying power to an in-vehicle auxiliary unit, an outputting unit outputting an AC signal to the connection path, and a diagnosis unit diagnosing presence/absence of the insulation failure based on a current flowing through the connection path when the AC signal is outputted. The diagnosis unit includes a storage unit storing a determination value for determining the insulation failure or information for setting the determination value. The determination value or the information is obtained by measuring an electrical state quantity of the connection path depending on stray capacitance and is dielectric resistance of the connection path obtained when an AC signal is outputted to the connection path. | 01-24-2013 |
20130076368 | Electric Vehicle Service Equipment Tester - A tester connects with the connector of electrical vehicle service equipment (EVSE). The tester simulates the battery supply of an electric vehicle to test whether the EVSE is properly operating without requiring that the electric vehicle be present. In one embodiment LEDs are employed to indicate whether the EVSE meets specifications. In a second embodiment various measurements of voltage levels and signals are provided to allow for a more detailed analysis of the performance characteristics of the EVSE. Ground fault, proximity sensor, and re-closure tests are also undertaken. | 03-28-2013 |
20130193979 | DEVICE AND METHOD FOR DETECTING A GROUND FAULT - An arrangement to detect a ground fault in an AC electric circuit including an electric machine having a neutral point connecting to a neutral point and a terminal side, and a unit transformer connected to the terminal side of the machine, wherein the arrangement includes a signal injection unit, a voltage transformer having a primary winding connected to the terminal side of the electric machine and a secondary winding that is open delta-connected, an instrument transformer having a primary winding connected to the neutral point of the electric machine and a secondary winding, and a ground fault detecting unit. The signal injection unit is configured to inject a signal to the secondary winding of the voltage transformer. The instrument transformer is configured to measure the resultant injected signal at its secondary winding The ground fault detecting unit is configured to detect a ground fault based on the measured signal. | 08-01-2013 |
20130278272 | Method and apparatus for high voltage isolation monitor for a vehicle - An apparatus for monitoring a high voltage isolation in a vehicle. The apparatus comprising a power conversion device for receiving a high voltage on a power bus. The power conversion device is configured to control a first switch for enabling a first known resistance to receive the high voltage and to measure a first voltage between a first node and a ground in response to the first known resistance receiving the high voltage. The power conversion device is further configured to measure a second voltage between a second node and the ground in response to the first known resistance receiving the high voltage and to determine a first leakage resistance between the first node and the ground based on at least the first voltage and the second voltage. The first leakage resistance indicating whether the high voltage is isolated from the ground. | 10-24-2013 |
20130285670 | GROUND FAULT DETECTION DEVICE, GROUND FAULT DETECTION METHOD, SOLAR ENERGY GENERATOR SYSTEM, AND GROUND FAULT DETECTION PROGRAM - A ground fault detection device detects a ground fault within a photovoltaic array in a solar energy generator system including a photovoltaic string composed of a plurality of photovoltaic modules connected in series, the photovoltaic array composed of a plurality of the photovoltaic strings connected in parallel, and a load device consuming or converting electric power. The ground fault detection device includes a switching section which parallels off the photovoltaic array or the photovoltaic string by electrically disconnecting the photovoltaic array or the photovoltaic string from the solar energy generator system and a detection section which detects a ground fault in the photovoltaic array or the photovoltaic string while the photovoltaic array or the photovoltaic string is paralleled off by the switching section. | 10-31-2013 |
20130293241 | METHODS AND APPARATUS TO DETECT LEAKAGE CURRENT IN A RESISTANCE TEMPERATURE DETECTOR - Methods and apparatus to detect leakage current in a resistance temperature detector are disclosed. An example method includes providing a resistance temperature detector circuit with a first resistance circuit and a second resistance circuit, measuring a first voltage at the first resistance circuit in response to applying a first current to the first resistance circuit, measuring a second voltage at the second resistance in response to applying a second current to the second resistance circuit, comparing the first and second voltages to determine a difference value, and determining that a current leak exists in the resistance temperature detector circuit when the difference value is not within a first range. | 11-07-2013 |
20130314099 | Electric Leakage Detection Apparatus - An electric leakage detection apparatus capable of performing voltage detection on electric equipment and quantitatively displaying a testing result includes a machine body coupled with a voltage detection circuit and a welding machine electric shock prevention detection module. The voltage detection circuit includes a first voltage detection unit intended to detect whether there is electric leakage in an electric equipment, and data of a detection time, an electric leakage current, a voltage, and an electric current are displayed on a data display unit of a display control module, whereby users can directly view the whole related data to ensure safe use of electricity. The welding machine electric shock prevention detection module is intended to detect a voltage at which an auto electric shock prevention apparatus of a welding machine operates, and to display the result on the display control module, whereby improving safe use of the welding machine. | 11-28-2013 |
20130335097 | Method And Device For Enhancing The Reliability Of Generator Ground Fault Detection On A Rotating Electrical Machine - A method for enhancing the reliability of generator ground fault detection based on a signal injection scheme, wherein the generator includes a winding. The method includes injecting a test signal at a predefined frequency to the winding, measuring an electrical quantity of a response signal in the winding resulted from the injected test signal, and detecting a ground fault based on the measured value of the electrical quantity. The method further includes continuously determining the frequency of the response signal, and discarding the present measured value corresponding to the determined frequency when the determined frequency deviates from the predefined frequency with a first threshold value. | 12-19-2013 |
20130335098 | Method For Adaptation Of Ground Fault Detection - A method for adapting a ground fault detection to a change of an electrical machine condition, wherein the machine includes a winding. The electrical machine is in a first machine condition, a first reference value being defined for measured values of an electrical quantity. The ground fault detection includes continuously measuring the electrical quantity in the winding and detecting a ground fault based on the measured values of the electrical quantity and the first reference value. The method includes receiving a signal, detecting a change of machine condition based on the received signal, and changing to a second reference value for the measured values of the electrical quantity, the second reference value being different from the first reference value when the change of machine condition is detected. | 12-19-2013 |
20140070815 | ACTIVE DIAGNOSTICS AND GROUND FAULT DETECTION ON PHOTOVOLTAIC STRINGS - A PV system includes a plurality of PV strings configured to generate a string output power responsive to received solar irradiation, with a source conductor and a return conductor being provided from the PV strings. One or more DC voltage regulators are electrically connected to the PV strings on at least one of the source or return conductors, with the DC voltage regulator being configured to regulate the voltage of a respective PV string or group of strings. A controller selectively controls a voltage output by the DC voltage regulator and is programmed to periodically cause the DC voltage regulator to alter the voltage of a PV string or group of strings, detect a change in current in the respective PV string(s) responsive to the altering of the voltage, and perform at least one of a PV string degradation detection and causal diagnosis and a grounded conductor fault detection. | 03-13-2014 |
20140084937 | On-Line Monitoring of Stator Insulation in Motors and Generators - Systems and methods are disclosed for on-line monitoring of the condition of the stator insulation of an AC motor or an electric generator. In certain embodiments, the system includes a transformer surrounding each pair of input and output cables associated with a given phase of power provided to the AC motor or generated by the electric generator. In another embodiment, a transformer surrounds the three input cables (for an AC motor) or the three output cables (for an electric generator) that correspond to phases of the AC motor or electric generator. In both embodiments, the transformers generate voltages that may be used to monitor leakage currents associated with the cables. A microcontroller monitors the voltages generated by the transformers and determines the condition of the stator insulation of the AC motor or the electric generator based on the voltages. | 03-27-2014 |
20140176152 | Method and Device for Detecting a Deterioration in the State of an Insulation in an Operating Electric Machine - The invention relates to a method and a device ( | 06-26-2014 |
20140247054 | LOW IMPEDANCE NEUTRAL AND DIAGNOSIS - A method to diagnose and localize parasitic voltages in an electric drive train is provided. The method includes manipulating a multiplexer to sequentially connect multiple diagnostic locations to a generator neutral, at predefined intervals. A voltage sensor senses a voltage transmission through a lead line that connects the multiplexer to the generator neutral. The voltage sensor generates a voltage signal and delivers that voltage signal to a controller, which compares the voltage signal to a predefined voltage threshold stored within. If the voltage signal exceeds the voltage threshold, the controller determines a parasitic voltage. Based on the location data of the diagnostic locations and the predefined intervals, the controller identifies at least one diagnostic location that experiences the parasitic voltage. Finally, the controller provides feedback in regard to the diagnostic location that experiences the parasitic voltage using the feedback interface. | 09-04-2014 |
20140253139 | FAULT DETECTION SYSTEM WITH LEAKAGE CURRENT DETECTION - A fault detection system for a machine having a plurality of electrical conducting elements insulated from a frame ground of the machine is disclosed. The fault detection system may include a high voltage DC power source, a positive high voltage bus connected to a positive terminal of the high voltage DC power source and providing high voltage electrical power to the plurality of electrical conducting elements, and a negative high voltage bus connected to a negative terminal of the high voltage DC power source and returning high voltage electrical power from the plurality of electrical conducting elements. At least one of the positive and negative high voltage buses may be selectively connected through a plurality of switches to plural zones of the electrical conducting elements, with each of the plural zones being electrically connected in parallel, and selectively connected to the high voltage DC power source by one of the plurality of switches. A low voltage DC power source may be configured to form part of a leakage current detector selectively connected through each of the plurality of switches to each of the plural zones for detecting leakage current between an electrical conducting element and the frame ground. | 09-11-2014 |
20150054523 | DEVICES AND TECHNIQUES FOR DETECTING FAULTS IN PHOTOVOLTAIC SYSTEMS - Devices and techniques for detecting faults (e.g., ground faults) in photovoltaic (PV) systems are provided. A fault-detection impedance component may be included in a PV system on the path to equipment ground. The PV system may determine whether a ground fault exists based, at least in part, on a measured impedance between a conductor of the PV system and a ground node of the PV system, and on a reference impedance. When it is determined that a ground fault exists in the PV system, action may be taken to mitigate the ground fault. | 02-26-2015 |
20150301098 | GROUND-FAULT DETECTOR FOR MULTIFURNACE INSTALLATION - An apparatus for detecting ground faults in a multifurnace installation with at least two induction furnaces and a multifurnace installation are described. A ground-fault sensor is associated with each induction furnace and is connected to the electrical supply line to the induction furnace coil. Furthermore, the apparatus has a ground-leak sensor. Moreover, the apparatus includes an additional ground-fault sensor that measures at the same location as the ground-leak sensor. In this manner an improvement of security during the operation of the system is obtained. | 10-22-2015 |
20160124038 | LEAKAGE CURRENT CALCULATION DEVICE AND METHOD FOR CALCULATING LEAKAGE CURRENT - Provided is a leakage current calculation device capable of calculating an accurate leakage current value in which the effect of noise has been suppressed. The configuration comprises: a to-ground voltage measurement means for measuring, over a predetermined interval, to-ground voltages inputted in each phase of a three-phase motor; a zero-phase current measurement means for measuring, over a predetermined interval, a zero-phase current, which is the to-ground leakage current that flows through the three-phase motor; a basic AC voltage waveform extraction means for extracting, from the to-ground voltage, a basic AC voltage waveform having a frequency in the same phase as the to-ground voltage of each phase; a frequency component extraction means for extracting, in the frequency band containing the frequency of the basic AC voltage waveform, a zero-phase current component of said frequency band; and a leakage current value calculation means for calculating the leakage current value I | 05-05-2016 |
20220132831 | DEVICE FOR TREATING SOIL AND METHOD FOR OPERATING SUCH A DEVICE - The invention relates to a device for treating a soil, comprising the following elements: a carrier vehicle having a chassis, a housing with electrical components such as in particular a high-voltage device for generating a high voltage, and high-voltage electrodes for introducing the high voltage into a first soil region. In accordance with the invention, it comprises a measuring device with evaluation electronics for measuring a fault current or a fault voltage between individual elements of the device with respect to one another or between individual elements and an earthing which serves to divert a fault current in a second floor region. | 05-05-2022 |