Abstract: A method for preventing ground fault in a three-phase electric transmission line system caused by a line break, includes: providing a programmable relay protection system, including a plurality of relay devices on each line, programmed to include: monitoring of acceptable preset parameter ranges of at least three pairs electric operating conditions, that include at least one high sensitivity instantaneous undercurrent and at least one high sensitivity condition selected from line differential overcurrent and negative sequence instantaneous overcurrent, zero sequence instantaneous overcurrent, and change in instantaneous undercurrent (and combinations thereof); permitting closed circuit operation when all of the lines show that the operating conditions are within the preset acceptable ranges; tripping a circuit breaker on a broken line when that line shows two operating conditions outside the preset parameter ranges; and shutting down power to the broken line before it otherwise causes a ground fault or other

Abstract: The invention relates to an electric circuit arrangement (2) for standard insulation monitoring with emergency shut-down for an ungrounded power supply system (4) upon detection of a ground fault, having a standard insulation monitoring device (10) which is coupled to an active conductor (L1, L2, L3) of the power supply system (4) on the network side via a coupling branch (12) each or to a neutral point (S) of the power supply system (4) via a coupling branch (12) and is connected to ground (PE) on the ground side via a ground connection branch (14).

Abstract: The disclosure describes various aspects of crowdsourcing traffic data for automatic and dynamic benchmarking of applications. In an aspect, an intelligence layer, communicatively coupled to a data collection layer and a visualization layer, is configured to receive traffic data from data sources (e.g., physical appliances, probes) in the data collection layer, the data sources being associated with multiple customers, and the traffic data being associated with at least one application (e.g., word processing, video streaming) used by the multiple customers. The intelligence layer is a cloud-based layer further configured to process the traffic data to determine performance thresholds for the at least one application, and may send one or more of the performance thresholds to a data source for a different customer to be used for benchmarking the at least one application for the different customer.

Abstract: A system for preventing ground fault in a three-phase electric transmission line system caused by a line break, includes: the transmission lines, a programmable relay protection system, including a plurality of relay devices on each line, programmed to include: preset parameter ranges of at least two electric operating conditions, at least one high sensitivity instantaneous undercurrent and at least one high sensitivity condition selected from line differential overcurrent and negative sequence overcurrent (and combinations thereof), the preset ranges being acceptable operating parameter ranges; monitoring; permitting closed circuit operation when all of the lines show that the two operating conditions are within the preset acceptable operating parameter ranges; tripping a circuit breaker on a broken line when that line shows that the two operating conditions are outside the preset parameter ranges; and shutting down power to the broken line before it otherwise causes a ground fault or other short circuit.

Abstract: A method for determining direction of an earth fault (EF) in a feeder of a high impedance grounded power system can be performed by an Intelligent Electronic Device (IED). The method includes obtaining a measure of a first order harmonic active current component derived from residual voltage and current of the feeder when the EF occurred in the feeder, obtaining a measure of a higher order harmonic reactive current component derived from the residual voltage and current of the feeder when the EF occurred in the feeder, and determining the direction of the EF in the feeder based on a combination of the first order harmonic active current component and the higher order harmonic reactive current component.

Abstract: Detection of, and protection against faults within a restricted earth fault (REF) zone of a transformer or a generator is disclosed herein. Security of the REF protection element uses comparison of a negative-sequence reference quantity. The REF condition is only detected when there is sufficient ground involvement and a fault in the reverse detection has not been detected. Dependability of the REF protection element in low-impedance grounded systems is improved by ensuring that the element operates when a zero-sequence reference quantity and a neutral operate quantity are orthogonal to each other. The REF protection element further determines an open CT condition and blocks detection of an REF fault upon determination of the open CT condition. A tripping subsystem may issue a trip command based upon detection of the REF condition.

Abstract: An electrical system includes a ground fault detection unit including a low frequency ground fault detection circuit and a high frequency ground fault detection circuit, and/or a ground fault control unit connected to the low frequency ground fault detection circuit and the high frequency ground fault detection circuit. The ground fault unit may be configured to detect a ground fault according to an output of the low frequency ground fault detection circuit and/or an output of the high frequency ground fault detection circuit. The electrical system may include a first current sensor connected to the low frequency ground fault detection circuit and/or a second current sensor connected to the high frequency ground fault detection circuit.

Abstract: A combined monitoring device for insulation-resistance monitoring and protective-conductor-resistance monitoring in a power supply system includes a grounded power supply system and an ungrounded power supply system, the combined monitoring device having a coupling circuit for being coupled to one or several active conductors of the grounded power supply system via coupling points, the combined monitoring device including an active monitoring device with a first operating mode for monitoring an insulation resistance in an ungrounded network state of the power supply system and a second operating mode for monitoring a protective-conductor resistance in a grounded network state of the power supply system, the combined monitoring device having an evaluation unit switchable between the first and second operating modes as a function of the ungrounded or grounded network state and configured for testing the insulation resistance in the first operating mode and the protective-conductor resistance in the second opera

Abstract: A method for providing negative sequence current to a bus of an IBR-based power system includes the steps of monitoring phase voltages at terminals connected to the power system and determining a reference phasor of a negative sequence voltage incident on the terminals. A rotation phasor is applied to the reference phasor based on an angular offset between a negative sequence voltage and a corresponding negative sequence current to obtain a first outbound negative sequence current having a first magnitude and a first phase angle. The first outbound negative sequence current is scaled to obtain a second outbound negative sequence current having a second magnitude that is different from the first magnitude and is oriented at the first phase angle. The second outbound negative sequence is provided to the bus of the power system.

Abstract: A method, control system and protective relay are provided for detecting faulted phases of transmission lines in an AC power system. The method includes sampling electric signals at one end of the transmission lines at a series of time points; computing instantaneous voltage values of electric signals at compensated points on the transmission lines from the values of the sampled electric signals based on a time domain lumped parameter differential equation for the transmission lines for the series of time points; recording the computed instantaneous voltage values of the electric signals; computing fault component or sudden-change of the instantaneous voltage values of the electrical signals; detecting the faulted phases or fault types by comparing the calculated fault component of the instantaneous voltage values at the preset compensated points; and generating signals indicating the faulted phases of fault types.

Abstract: A method for monitoring an AC voltage source, which is DC-decoupled from a reference potential and which generates an AC voltage between two AC voltage lines. Each of the AC voltage lines is coupled to the reference potential by way of a respective capacitive voltage divider and a respective component voltage signal is tapped at the voltage dividers and at least one root mean square value signal is generated therefrom and a check is carried out to determine whether the respective root mean square value signal meets a predetermined triggering criterion. When the triggering criterion is met, a fault signal is generated.

Abstract: The proposed invention discloses a safe processing method for active voltage reduction of a ground fault phase of a non-effective ground system, for use in safe processing of a ground fault of a neutral point non-effective ground generator or distribution network. Non-effective ground system side windings of a transformer are equipped with a plurality of shunting taps. When a single-phase ground fault occurs, the shunting tap of the fault phase winding is selected to be short-circuited to ground directly or through an impedance to reduce the fault phase voltage to ensure that the fault point voltage is less than the continuous burning voltage of a ground arc to meet a long-term non-stop safe operation requirements. The proposed method can eliminate the instantaneous single-phase ground fault, suppress the permanent single-phase ground fault current, and limit the rising amplitude of non-fault phase voltage and the risk of non-fault phase insulation breakdown.

Abstract: A drive system includes a current sensor configured to generate a first current signal representative of a current flowing in one or more electrical devices electrically coupled together through a power supply bus, a power output bus, and a common ground. The drive system also includes a voltage sensor configured to generate a first voltage signal representative of a voltage with respect to the common ground in the one or more electrical devices. The drive system further includes a ground fault detection controller configured to determine a ground fault in the one or more electrical devices based on a change in at least one of the first current signal and the first voltage signal.

Abstract: A protection circuit provides a control voltage to a 3-phase contactor, where the three phases of the 3-phase power supply are inputs to the 3-phase contactor. The protection circuit includes: four input terminals, configured to be connected respectively to the three phases and to the neutral line of the 3-phase power supply; an output terminal, providing the control voltage to a control line of the 3-phase contactor; and control circuitry configured to provide the control voltage when any one or more of the three phases are live and when the neutral line is connected, and to provide no control voltage when all three phases are disconnected or when the neutral line is disconnected.

Abstract: The present invention provides a method for current for fault identification in a transmission line and an apparatus thereof. The method comprises the following steps: measuring the real-time values of the currents and the voltages of the other unbroken healthy phase conductors when a single-phase fault occurs; calculating the inductive voltage and the capacitive coupling voltage according to the measured currents and voltages respectively; comparing the capacitive coupling voltage with the inductive voltage multiplied by a factor, in which the multiplication result is used as a self-adjusted threshold based on the real time load condition of the transmission line; and identifying the fault type based on the maximum of the capacitive coupling voltage and the multiplication.

Abstract: This disclosure provides systems, methods, and apparatuses for current monitoring. For example, in a system that includes a first circuit breaker coupled to a primary power source and a second circuit breaker coupled to an alternative power source, there is provided an apparatus that includes a controller circuit configured to prevent back-feeding of power from the alternative power source to the primary power source via tripping the second circuit breaker, in response to the total current in the first and second circuit breakers exceeding a defined maximum level.

Abstract: An apparatus for mitigating GIC (geomagnetically induced current) effects through a fuzzy logic controlled variable resistor. Under GIC conditions (or any unbalanced fault current condition), the GIC or unbalanced fault current flows through the neutral of a power transformer. It is detected by the fuzzy logic controller, which sends a signal to a switch to open. The resistor is in the circuit and impedes the flow of current through the neutral, thereby protecting the transformer from getting overheated.

Abstract: A multifunctional signal isolation converter (10) is arranged in a safe area (20), and is applied to an electronic apparatus (40) arranged in a dangerous area (30). The multifunctional signal isolation converter (10) includes a microprocessor (108) and a power supply unit (116). The microprocessor (108) determines whether internal functions of the multifunctional signal isolation converter (10) are normal or not to obtain a first judgment value. The electronic apparatus (40) sends an input signal (42) to the microprocessor (108). The microprocessor (108) determines whether functions of the electronic apparatus (40) are normal or not to obtain a second judgment value according to the input signal (42). The microprocessor (108) controls whether the power supply unit (116) supplies a driving power (122) to the electronic apparatus (40) or not according to the first judgment value and the second judgment value.

Abstract: The present disclosure is a system for monitoring power that has a unified polyphase distribution transformer monitoring (PDTM) device that interfaces with at least three electrical conductors electrically connected to a transformer. In addition, the PDTM device measures a current and a voltage of each of the three electrical conductors. Additionally, the system has logic that calculates values indicative of power corresponding to the transformer based upon the currents and the voltages measured and transmit data indicative of the calculated values.

Abstract: A noise signal for a malfunction test is inputted to a ground terminal, and a frequency property of the magnitude of the power at which a designated electric circuit causes a malfunction is found. A detection reference ground of a detection part for detecting malfunctions of the designated electric circuit is connected at high impedance to a ground of the targeted circuit. Differential input parts are provided to the detection part, a to-be-detected part of the designated electric circuit is connected to one differential input part, and the ground of the targeted circuit is connected to the other differential input part. A ground of a noise source is isolated from a ground of a power source circuit for supplying a power source to the designated electric circuit. The ground of the noise source is galvanically isolated from the ground of the designated electric circuit.

Abstract: Methods for detecting a short fault of an alternator rectifier electronic component include sampling a field winding voltage or current signal of an alternator, during operation of the alternator, and determining a fault ripple period at which the alternator field winding signal exceeds a fault threshold. A short fault of an electronic component of a rectifier coupled to the alternator is detected in the event that the fault ripple period closely matches an alternator armature period. Alternatively or additionally, the sampled field winding signal is band pass filtered, and a short fault is detected in the event that an amplitude of the band pass filtered field winding signal exceeds a fault threshold. The methods can be implemented, for example, by an apparatus that includes a hysteresis frequency counter, a frequency comparator, and a countdown timer.

Abstract: A first X capacitor is connected between one of a plurality of hot line sections of a hot line that is located at an output side of a first relay as viewed from a commercial alternating-current power supply, and one of a plurality of neutral line sections of a neutral line that is located at an input side of a second relay as viewed from the commercial alternating-current power supply. A second X capacitor is connected between one of the hot line sections that is located at the output side of the first relay as viewed from the commercial alternating-current power supply, and one of the neutral line sections that is located at an output side of the second relay as viewed from the commercial alternating-current power supply.

Abstract: The present invention includes a method for providing ground fault protection to a generator. The method includes determining the existing state of the generator and second, determining the updated alarm or trip conditions of a relay connected to the generator in view of the existing state of the generator. This includes estimating a ratio of the magnitude of the 3rd harmonic neutral voltage to the magnitude of the 3rd harmonic terminal voltage of a generator, along with calculating the residual 3rd harmonic voltage from the estimated 3rd harmonic ratio. From this, a comparison is made between the energy of the residual voltage with a fractional energy of the 3rd harmonic neutral voltage. Based on this comparison, an alarm or trip condition is signaled when the energy of the residual voltage is greater than the fractional energy of the 3rd harmonic neutral voltage.

Abstract: A system for measuring current includes a current monitoring system comprises a current sensor configured to sense a first current passing through a conductor and a voltage conversion device coupled to the current sensor and configured to receive a second current from the current sensor and convert the second current into a first voltage. A first scaling circuit is coupled to the voltage conversion device and configured to convert the first voltage to a second voltage proportional to the first current based on a first scaling factor, and a second scaling is circuit coupled to the voltage conversion device and configured to convert the first voltage to a third voltage proportional to the first current based on a second scaling factor, wherein the second scaling factor is different from the first scaling factor.

Abstract: A system and method for detecting high resistance ground faults in a power distribution system is disclosed. A fault detection and protection system is provided that includes a plurality of current sensors to measure current on the three phase output of the converter-inverter arrangement of the power distribution system and a controller configured to measure the three phase current on the three phase output, extract a fundamental current component for each phase of the three phase output, extract a third harmonic component for each phase of the three phase output, compare the fundamental current component and the third harmonic component extracted from each phase to a first threshold and a second threshold, respectively, and detect a ground fault on a phase of the three phase output based on the comparisons of the fundamental current component and the third harmonic component to the first and second thresholds.

Abstract: A feeder power source for a network power system includes a network transformer having a delta three-phase primary winding and a three-phase secondary winding; a three-phase primary feeder electrically connected to the delta three-phase primary winding; a three-phase secondary bus electrically connected to the three-phase secondary winding; and a three-phase electrical switching apparatus structured to open and close the three-phase primary feeder. A network protector includes a network relay and a three-phase circuit breaker structured to open and close the three-phase secondary bus. A first circuit is electrically connected between at least one phase of the three-phase primary feeder and ground, and is structured to unbalance shunt impedance to the three-phase primary feeder ground. A second circuit detects a shift in system neutral and detects that the three-phase primary feeder is opened by the three-phase electrical switching apparatus.

Abstract: An open neutral protection method and apparatus including a blocking diode arrangement to prevent connection of power in circuits when the power source has an open neutral. In particular, when more than one branch circuits are connected to a power supply with more than one hot power lines, blocking diodes prevent back feed currents from activating relays connecting the power source to the branch circuits when the power source has an open neutral.

Abstract: A power distribution system includes multiple uniform power distribution modules and multiple uniform mating connectors. A portion of the mating connectors are connected to the power distribution modules directly and the remainder are connected to the power distribution modules via a ground fault interrupt adapter.

Abstract: A separately excited synchronous machine (1b1k) with an excitation circuit on the side of the rotor includes an excitation winding (3) and a power supply for the excitation winding (3) as well as a switching element (8a, 8e) for connecting the power supply to the excitation winding (3). Further, the synchronous machine (1b1k) comprises a first stator-side primary winding (5a5f) and a first rotor-side secondary winding (6a6f). Moreover, the synchronous machine (1b1k) may comprise a) a tap of the first rotor-side secondary winding (6d) connected to a control element (9a, 9e) of the switching element (8a, 8e) or b) a second rotor-side secondary winding (14d), which is coupled to the first stator-side primary winding (5a5f) and connected to a control element (9a, 9e) of the switching element (8a, 8e).

Abstract: Methods may be provided to control an electro-permanent magnetic device powered from an AC mains power source provided through first and second power lines of a controller, wherein a first switch is provided on the first power line between the AC mains power source and the electro-permanent magnetic device and a second switch is provided on the second power line between the AC main power source and the electro-permanent magnetic device. In particular, a sequence of switching pulses may be transmitted through the first and second switches to change a magnetic state of the electro-permanent magnetic device. Related controllers are also discussed.

Abstract: A three-phase GFCI device is disclosed. The three-phase GFCI device may include contactors, a contactor control module configured to cause the contactors to close during normal operation of the GFCI device and open based on receiving a fault signal, a current detection module, a transient suppression module, a miswire detection module, a ground-fault test module, a ground load detection module, and a fail-safe module. In some examples, the GFCI device may include the stated modules in accordance with the UL 943C standard.

Abstract: A circuit interrupter includes a trip actuator configured to cooperate with an operating mechanism to trip open separable contacts. The circuit interrupter also includes a ground fault sensor configured to sense a difference between a current through a first electrical conductor and a current through a second electrical conductor and to output an output current based on the sensed difference and a ground fault amplifier circuit configured to convert the output current to an output voltage. The circuit interrupter also includes first and second switches configured to electrically connect the output of the ground fault sensor to the ground fault amplifier circuit and the trip actuator, respectively. The circuit interrupter also includes a processor configured to control operation of the first and second switches and, when the first switch is closed, to control operation of the trip actuator based on the output voltage.

Abstract: An open neutral protection method and apparatus including a blocking diode arrangement to prevent connection of power in circuits when the power source has an open neutral. In particular, when more than one branch circuits are connected to a power supply with more than one hot power lines, blocking diodes prevent back feed currents from activating relays connecting the power source to the branch circuits when the power source has an open neutral.

Abstract: A fault signal indicates a single-pole or a double-pole fault in a three-phase electrical power grid which occurred during a present electric oscillation in the electrical power grid. The method assures that single-pole or double-pole faults occurring during oscillation can be detected with high reliability in that a symmetry signal is produced during the oscillation, which indicates whether the oscillation is symmetrical or unsymmetrical, and the phases of the electrical power grid are checked for an existing fault, wherein the symmetry signal is used for carrying out the check. The fault signal is produced if a fault was detected during the check. A protective device has an accordingly equipped control unit.

Abstract: The invention relates an inverter that may be set up as part of a power generation system for the connection of a number of substrings, which, using DC switches, can be connected to each other in series into a string and with the inverter. The inverter includes a bridge circuit to transform the power generated by the string comprising series-connected substrings into a grid-compatible AC voltage and to feed the power into a grid. The inverter also includes a ground fault detector arranged on the AC side of the bridge circuit for ground fault monitoring of the string. A controller connected to the ground fault detector controls the DC switches so that in case of a ground fault, a complete decoupling of the connection of the string from the bridge circuit and a separation of the string into potential-free substrings is performed. A method of operating such a power generation system is also described.

Abstract: Electrical load controls are provided which include an electrical switch assembly and a fault protection device within a common housing. The switch assembly includes an actuator, and is responsive to actuation of the actuator to switch ON or OFF electricity to the load. The protection device automatically responds to a fault condition by overriding the switch assembly by automatically blocking electrical connection between phase input and output terminals and neutral input and output terminals of the load control. The actuator includes a single external interface element. In one embodiment, actuation of the actuator switches ON or OFF electricity via control of the fault protection device, and in another embodiment, movement of the interface away from the housing exposes within the housing an internal user interface for the fault protection device.

Abstract: A first protective device monitors a first section of a power supply network for a symmetrical short-circuit and a second protective device monitors a second section for a symmetrical short-circuit. The second protective device is a reserve protective device, which emits a shut-off command to a power switch after a time lag when a symmetrical short-circuit in the first section is recognized. An oscillation recognition unit emits an oscillating signal which blocks the shutoff command if an oscillation in the power supply network has been recognized. External symmetrical short-circuits can be disconnected independently of an occurring oscillation, when the second protective device has recognized a symmetrical short-circuit in the first section, before the oscillation recognition unit recognizes an oscillation in the power supply network, the shut-off command is emitted independently of the presence of an oscillating signal if the lag time has elapsed.

Abstract: A power distribution system includes multiple uniform power distribution modules and multiple uniform mating connectors. A portion of the mating connectors are connected to the power distribution modules directly and the remainder are connected to the power distribution modules via a ground fault interrupt adapter.

Abstract: Various methods and apparatus are described for a photovoltaic system. In an embodiment, a hybrid grounding circuit as well as a ground fault monitoring circuit are in the inverter circuitry with its switching devices that generate three-phase Alternating Current (AC) voltage. The three-phase AC voltage is supplied to a utility power grid interface transformer, where a primary-side common node of the Utility Power grid interface transformer is connected to Earth ground. Each inverter has 1) its own set of isolation contacts to connect as well as isolate this particular inverter from the utility grid interface transformer, and 2) control components in the ground fault monitoring circuit for controlling operation of the isolation contacts based off a presence of the ground fault detected by the ground fault monitor circuit for that inverter. The inverter circuit receives a DC voltage supplied from its own set of ungrounded Concentrated PhotoVoltaic modules.

Abstract: A system and method for a vehicle control system is disclosed herein. The system includes an inverter circuit, a permanent magnet synchronous motor, and a crossover connected between the inverter circuit and the permanent magnet synchronous motor. The system may also include at least one current sensor installed between the inverter circuit and the permanent magnet synchronous motor. A contactor may also be connected between the inverter circuit and the permanent magnet synchronous motor and may pass or shut off electricity between the inverter circuit and the permanent magnet synchronous motor. The system may also include a control unit connected to the contactor and the current sensor. The control unit may detect a current abnormality using information from the current sensor and open the contactor if an abnormality is detected.

Abstract: The present invention relates to a ground fault detecting and controlling method for a parallel-structured high voltage system, and more particularly, such a ground fault detecting and controlling method for a parallel-structured high voltage system, in which it can be more precisely determined whether or not the system operation is emergently stopped based on individual insulation resistance values for respective items of the system, and it can be determined whether there is the possibility of temporary operation of the system in the emergency stop situation of the system operation. According to the present invention, a combined insulation resistance ground fault reference value is calculated based on individual insulation resistance values for respective items of the system, and the entire system is controlled by using the calculated combined insulation resistance ground fault reference value such that a high-accuracy ground fault detecting and controlling method can be provided.

Abstract: For monitoring the isolation of an IT-grid with respect to ground, an inverter connecting a direct current side with an alternating current side of the IT-grid and a photovoltaic device on the direct current side of the IT-grid, at least one isolation resistance of the direct current side with respect to ground is monitored for falling below a resistance threshold value while the inverter is running, and additionally a leakage current via the inverter towards ground is monitored for exceeding a current threshold value.

Abstract: An appliance and a method are intended to monitor a phase line of a section of an electrical energy grid line. The appliance comprises a device for monitoring a parameter of a phase line. The parameter is representative of routine operating conditions of the phase line and has a known propagation speed. The appliance also comprises a device for generating an event detection signal each time the parameter has a value that exceeds a threshold, and for storing a reception time when the detection signal is generated. The appliance also has a device for sending a signal representative of a geographic location of the end of the section and a device for performing a geographic location of the event once two consecutive detection signals are generated from the signal representative of the geographic location, and reception times associated with the two detection signals.

Abstract: Disclosed herein is an abnormal current detection circuit for circuit breaker, comprising a full-wave amplifier, a positive wave-period comparator for comparing a positive wave-period amplification voltage signal with a positive wave-period reference voltage signal to output a pulse signal, a negative wave-period comparator for comparing a negative wave-period amplification voltage signal with a negative wave-period reference voltage signal to output a pulse signal, a combining circuit for combining pulse signals outputted from the positive wave-period comparator and the negative wave-period comparator to output a full-wave combining signal, a reference voltage generator for generating a reference voltage signal, and a comparative driving circuit section for comparing the combining signal with the reference voltage signal to output a signal for controlling a circuit breaker to be driven to a circuit breaking position when the combining signal is greater or equal to the reference voltage signal.

Abstract: A residual-current circuit breaker includes at least one summation current transformer through which at least one first lead and one second lead of a network to be protected are guided. At least one secondary winding is arranged on the summation current transformer and operatively connected at least indirectly with at least one energy storage element. At least one discharging resistor is switched in parallel with the energy storage element. The residual-current circuit breaker has a trip element which is operatively connected with break contacts in the at least one first lead and the at least one second lead. In order to reduce unexpected cut-offs of a network to be protected, the at least one discharging resistor includes a first partial resistor, and a second partial resistor switched in series with respect to the first partial resistor, with a least one electric signaling device operatively connected, at least indirectly, with the first partial resistor.

Abstract: An apparatus and method for providing ground fault protection to a lifting device utilizing an electromagnet and powered by a generator. The apparatus and method rectifies an AC voltage emanating from the generator source and monitors unsafe operating conditions of the generator's circuit wherein operation of the lifting device is ceased when predetermined electrical operating parameters are exceeded.

Abstract: The present invention relates generally to systems and methods for detecting ground faults (i.e., line-to-ground faults) in electrical power conversion systems. In particular, the embodiments described herein include a common mode voltage booster module configured to calculate a common mode voltage boost factor and a common mode voltage boost function based on a plurality of voltage commands for the system. The common mode voltage boost factor and/or the common mode voltage boost function may be applied to the voltage commands to generate boosted voltage commands which, when applied to an inverter or converter, source current indicative of ground faults in the system. More specifically, the common mode voltage boost factor may be multiplied by a common mode voltage calculated by a common mode voltage calculator and summed with the voltage commands.

Abstract: A differential-current switch includes a first unit arranged in an electric power supply network for detecting a differential current and outputting an analog differential current signal, an analog-to-digital converter receiving the outputted analog differential current signal and converting the outputted analog differential current signal to a digital differential current signal, a first digital signal processing unit receiving the digital differential current signal, a second unit for disconnecting circuit breaker contacts in the electric power supply network, and first means connected upstream of the analog-to-digital converter for adjusting the analog differential current signal. Adjustment of the analog differential current signal provides favorable resolution of a differential current signal over a wide dynamic range.

Abstract: Current differential protection with charging current compensation is provided for a power apparatus, such as a power transmission line. Individual terminals dynamically determine their respective contributions, if any, to the charging current compensation value as availability of one or more voltage sources dynamically changes within the power apparatus. Respective terminals calculate local contributions to a charging current compensation value based on local voltage measurements. A loss of a voltage source is handled by adjusting multipliers for the remaining compensation points to reflect the total charging current. A local contribution is suppressed when the local voltage source is no longer available. After applying the local contributions, an alpha plane analysis may be used to determine when to trip the power apparatus.

Abstract: An automotive vehicle includes a charge port integrated with the vehicle. The charge port includes electrical contacts configured to receive electrical power from an electric grid, and a fault interrupt circuit electrically connected with the electrical contacts.