Abstract: A conventional ground fault interrupter in an arrangement with a frequency converter and electrical machines may be accidentally tripped due to operation-related leakage currents. This can be prevented by operating a ground fault interrupter for a frequency converter receiving a mains current in the following manner: receiving switching information about switching operations in the frequency converter, measuring a signal associated with a common mode current in a power line device which conducts the mains current to the frequency converter, determining, based on the switching information, an expected signal expected for the common mode current produced by the switching operations, identifying, based on the measured signal and the expected signal, a fault current, and interrupting the mains power depending on the identified fault current. A ground fault interrupter is hereby provided with an evaluation unit configured to carry out the method.

Abstract: A method for simulating an arc flash event on an electrical power system is disclosed. The virtual system model of the electrical system is modified to introduce a short circuiting feature. The standard to supply equations used in the arc flash event calculations is chosen. The arc flash event is simulated using the modified virtual system model in accordance with the chosen standard. The quantity of arc energy released by the arc flash event is calculated using results from the simulation. The report that forecasts an aspect of the arc flash event is communicated.

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

Abstract: High-power power distribution in an aircraft may use solid state power controller (SSPC) technology. A conventional electromechanical contactor may be used, in series, with a solid state switching device (SSSD) to achieve high-power power distribution. Since the electromechanical contactor does not need to be rated for arc handlings during normal SSPC operation, the electromechanical contactor may be simplified, resulting in cost, weight, volume, and failure rate reductions. The power distribution apparatus and methods of the present invention may be applicable for both alternating current (AC) and direct current (DC) applications and can be modified to form a three phase SSPC.

Abstract: The present invention is directed to an electrical wiring device for use in an electrical distribution system. The device includes a plurality of line terminals configured to terminate the plurality of line conductors and a plurality of load terminals configured to terminate the plurality of load conductors. The protective circuit assembly includes at least one fault detector configured to generate a fault detection signal based on electrical perturbations propagating on at least one of the plurality of line terminals or at least one of the plurality of load terminals. A device integrity evaluation circuit includes a timing circuit coupled to the source of AC power by way of the plurality of load terminals and configured to generate a time measurement. The device integrity evaluation circuit is configured to reset the time measurement if the protective circuit assembly generates the fault detection signal during a predetermined test interval in the properly wired condition.

Abstract: A first battery pack (252-1) comprises a battery module (314) which includes a plurality of battery cells (310) connected in series between a positive terminal (352) and a negative terminal (353), ground-fault resistances (45) each of which appears between a grounding point (23) and an inter-battery connection point (311) between adjoining ones of the battery cells (310), a booster unit (11) which is provided to the positive terminal (352) and outputs boosted electric potential acquired by boosting high electric potential of the battery module (314), a protective resistance (25) and a ground fault detecting resistance (27) which are provided in series between a third connection point (19) (on the output side of the booster unit (11)) and the grounding point (23), and a ground fault detecting unit (41) which detects the presence/absence of a ground fault in the battery module (314) based on the result of comparison between preset threshold electric potential (Vref) and electric potential of an inter-resistance

Abstract: This document discusses, among other things, a self-test (ST) ground fault circuit interrupter (GFCI) monitor configured to generate a simulated ground fault starting in a first half-cycle of a first cycle of AC power and extending into a second half-cycle of the first cycle of AC power, wherein the first half-cycle of the first cycle of AC power precedes the second half-cycle of the first cycle of AC power. Further, the ST GFCI monitor can detect a response to the simulated ground fault.

Abstract: The power supply control device of the present invention includes: a set of power reception conductors; a set of power supply conductors; a set of intermediate conductors electrically connected to the set of power reception conductors, respectively; a set of relays configured to make and break electrical connections between the set of intermediate conductors and the set of power supply conductors, respectively; a zero-phase current transformer positioned to allow the set of intermediate conductors to pass through an inside of the zero-phase current transformer; a control circuit for controlling the set of relays responding to a detection result of the zero-phase current transformer; and a body block including a first block and a second block fixed to the first block. The set of power reception conductors and the set of power supply conductors are fixed to the first block. The set of intermediate conductors is fixed to the second block.

Abstract: A connection diagnostic apparatus for a ground fault detector including an oscillator connected via a coupling capacitor to an electric circuit with a first connection line and a second connection line, and a voltage detector for detecting a voltage value between the oscillator and the coupling capacitor is provided with a first relay and a second relay provided in the first connection line and the second connection line, and a programmable controller. The programmable controller determines a connected state of the ground fault detector based on a change amount of a voltage value detected by the voltage detector when the first relay is turned on or off and determines the connected state of the ground fault detector based on a change amount of a voltage value detected by the voltage detector when the second relay is turned on or off.

Abstract: The present invention relates to an electric appliance (100) comprising an electric load (225), and a printed circuit board assembly (115) for electronically managing the electric appliance (100); the printed circuit board assembly comprises a slave printed circuit board (220s) operatively associated with the electric load (225) for driving it, and a master printed circuit board (220m) operatively associated with the slave printed circuit board (220s) and arranged for receiving an electric power supply (L, N) of the electric appliance and for selectively providing/stopping the provision of an operative electric power to the slave printed circuit board (220s) for energization/de-energization thereof.

Abstract: An electrical safety system with an integrated timer is disclosed. The electrical safety system may have an input line connected to an output via one or more communication paths. The electrical safety system may also have a ground fault circuit interrupter module including a sensor coil for monitoring current passing from the input line to the electrical load and producing a current signal and a ground fault circuit interrupter circuit. Further, the electrical safety system may have one or more switches for opening or closing the one or more communication paths between the input line and the output, and a solenoid for operating the one or more switches. Additionally, the electrical safety system may have a timer module comprising a timer circuit configured to generate a timer signal and a selector switch in electrical communication with the timer circuit and a visual display.

Abstract: A Ship Board Ground Monitor System measures an antistatic bond between a ship and a loading-off-loading facility during operation and an earth ground while in the process of loading or unloading flammable materials. The system ensures that a maximum adjustable, preset resistance between the ship transport and safety ground is not exceeded. Should this resistance be exceeded, the control apparatus within the system will activate audible and visual annunciation and provide a contact output, which may be used to disable pumping systems.

Abstract: An apparatus and method for detecting an arc fault using a power conductor on a printed circuit board (PCB), which supplies power from an external power source to electrical components on the PCB by sensing a value indicative of the rate of change of current passing through the power conductor. The apparatus and method may be used for detecting arc faults both internal and external to the PCB.

Abstract: Software code for operating a circuit interrupting device having an auto-monitoring circuit for automatically testing various functions and structures of the device. The auto-monitoring circuit initiates the software code which includes an auto-monitoring routine which, among other things, establishes a self-test fault during the positive or negative half-wave of an AC power cycle and determines whether the detection mechanisms within the device properly detect the self-test fault. An early detection signal indicates that the self-test fault was properly detected without interfering with the normal operation of the detection circuitry and without causing a false trip within the device. Additional functionality of the software code permits automatic verification that the device is properly wired, that is, not miswired, and determines whether the device has reached the end of its useful life.

Abstract: The present invention is directed to an electrical wiring device that includes a processing circuit is configured to determine the wiring state based on detecting a wiring state parameter at the plurality of line terminals during a predetermined period after the tripped state has been established. The processing circuit is configured to store a wiring state indicator in a wiring state register based on a wiring state determination. The wiring state register being preset to trip the circuit interrupter when the AC power source is applied by an installer to the plurality of line terminals or the plurality of load terminals for the first time.

Abstract: A method and circuit for detecting and clamping current in a ground fault circuit interrupter circuit. In accordance with an embodiment the circuit includes an amplifier connected to a switch, where in the amplifier has an input connected to a first conduction terminal of the switch through a resistor and another input connected to a second conduction terminal of the switch. An output of the amplifier is connected to a control terminal of the switch. The circuit may include a ground fault circuit interrupter engine having an input connected to the first conduction terminal of the switch and another second input connected to the second conduction terminal of the switch.

Abstract: A circuit interrupting device having an auto-monitoring circuit for periodically testing various functions and structures of the device. The auto-monitoring circuit initiates an auto-monitoring routine which, among other things, generates a self-test fault condition and determines whether the detection mechanisms within the device properly detect the self-test fault. Processing an early detection signal determines whether the self-test fault was properly detected without interfering with the normal operation of the detection circuitry and without causing a false trip within the device. Additional functionality of the auto-monitoring circuit permits automatic verification that the device is properly wired, that is, not miswired, and determines whether the device has reached the end of its useful life.

Abstract: A circuit interrupting device having an auto-monitoring circuit for automatically testing various functions and structures of the device. The auto-monitoring circuit initiates an auto-monitoring routine which, among other things, establishes a self-test fault during either the positive or negative half-wave, or both, of an AC power cycle and determines whether the detection mechanisms within the device properly detect the self-test fault. An early detection signal indicates that the self-test fault was properly detected without interfering with the normal operation of the detection circuitry and without causing a false trip within the device. Additional functionality of the auto-monitoring circuit permits automatic verification that the device is properly wired, that is, not miswired, and determines whether the device has reached the end of its useful life.

Abstract: A protection system configured to couple between a generator that has a number of partial strings and an inverter includes a control device, and a series-connection switching device configured to selectively connect the partial strings together in series. The system also includes a parallel-connection switching device configured to selectively connect the partial strings together in parallel, wherein the series-connection switching device is actuated by the control device such that it interrupts the series connection of the partial strings in case of a hazard, and the parallel-connection switching device is actuated by the control device such that it connects the partial strings together in parallel in case of a hazard.

Abstract: In a switching device with at least one first electrical switching device input and at least one first electrical switching device output and at least one second electrical switching device output, wherein in a first operating state of the switching device the first switching device input is electrically connected with the first switching device output, wherein in a second operating state of the switching device the first switching device input is electrically connected with the second switching device output, is proposed to configure the switching device for uninterrupted switchover from the first operating state to the second operating state and/or from the second operating state to the first operating state to allow functional testing of a fault current circuit breaker without interruption.

Abstract: A protection apparatus is for a direct current electrical generating apparatus. The protection apparatus includes a first terminal; a second terminal; a third terminal; a fourth terminal; at least one current sensor structured to sense current flowing between the first and second terminals or between the third and fourth terminals; a voltage sensor structured to sense a voltage between the first terminal and the third terminal; at least one switch structured to interrupt the current flowing between the first and second terminals or between the third and fourth terminals; and a processor cooperating with the at least one current sensor, the voltage sensor and the at least one switch, and being structured to provide feed forward fault protection for the direct current electrical generating apparatus.

Abstract: The present invention is directed to a protective device configured to be coupled between an AC power source and an electrical load. A ground continuity monitor is coupled to the ground conductor, the ground continuity monitor being configured to detect a ground discontinuity condition in the ground conductor. A circuit interrupter mechanism is configured to interrupt electrical continuity in a tripped state and establish electrical continuity in a reset state. A self-test circuit is coupled to the ground continuity monitor and configured to perform a simulated ground continuity test that simulates the ground discontinuity condition. The self-test circuit provides a test failure signal when the ground continuity monitor fails to provide an output signal in response to the simulated ground continuity test. The test failure signal is configured to trip the circuit interrupter mechanism.

Abstract: A resettable switching apparatus, useful in a GFCI receptacle, has a space-efficient coaxial configuration in which a mechanical latching arrangement for resetting (i.e., closing) main switch contacts is disposed inside the trip solenoid. A movable carriage for the main contacts spans one end of the solenoid and has a latching portion in the solenoid that engages the inner end of a reset plunger in two sequential states (i.e., unlatched and latched). An electrical miswire feature is included to prevent the device from being reset until the AC power is properly connected to the device and inadvertent failure of the miswire feature due, for example, to dropping the device prior to installation is avoided. Also, an enhanced self-test, or auto-monitoring, feature is provided that is more robust than that which has been previously disclosed.

Abstract: A power plug, including: a shell, the shell having two sides, a reset button and a test button protruding from the first side, and a live wire pin and a neutral wire pin protruding from the second side; a circuit board; a stationary contact; a movable contact; a tripping device; a cross arm; and a push block. The stationary contact is connected with the live wire pin and the neutral wire pin; the movable contact can be connected to or disconnected from the stationary contact. The tripping device includes a sliding pedestal and a sliding part and controls the connection between the movable contact and the stationary contact. An elastic member is disposed on the push block. An ejector spring is disposed on one end of the movable armature. A reset spring is disposed between the sliding part and the sliding pedestal.

Abstract: A ground fault protection system is disclosed. The ground fault protection system may include a controller that is configured to receive signals representing a ground fault detection voltage and a DC link voltage of the machine. Based on the ground fault detection voltage and the DC link voltage, the controller may determine a ground fault detection percentage value. Based on the ground fault detection percentage value and the DC link voltage, the controller may further determine a worst case component insulation voltage. The controller may compare an absolute value of the worst case component insulation voltage with a rated insulation voltage of a component of the machine. When the absolute value of the worst case component insulation voltage is higher than the rated insulation voltage, the controller may determine a new DC link voltage based on the rated insulation voltage and the ground fault detection percentage value, and may output a signal for operating the machine by using the new DC link voltage.

Abstract: A device for interrupting the flow of electrical power in an electrical distribution system is provided. The device includes a sensor operably coupled to the electrical distribution system. A switching mechanism is coupled to the electrical distribution system, the switching mechanism movable between an open position and a closed position. A controller operably coupled to the sensor and the switching mechanism, the controller having a processor that is responsive to executable computer instructions when executed on the processor incrementing a first counter in a first mode of operation and a second counter in a second mode of operation. Wherein the processor is further responsive to executable computer instructions for switching from the first mode to the second mode in response to a signal from the sensor.

Abstract: To prevent property fires, electrical circuits need to be protected from arc faults due to line-to-line, line-to-neutral and line-to-ground conductivity, known as high current parallel arcing, and protected from arc faults occurring along line-to-line, line-to-load, load-to-load, load-to-neutral and neutral-to-neutral conductor configurations, known as low current series arcing. Devices that protect electrical circuits from these arc faults is known as a combination-type arc fault circuit interrupter (AFCI).

Abstract: A method for enabling an ETU to function as a host controller is provided. The ETU includes a power bus port, a current sensor input, and a power distributor coupled to the power bus port and the current sensor input. The method includes determining that a peripheral device is connected to the power bus port. The method further includes determining that sufficient input power is available to the ETU to provide an output power to the peripheral device through the power bus port. Additionally, the method includes providing the output power to the peripheral device through the power bus port.

Abstract: Embodiments of the invention are directed to systems and methods using an interruption device for automatically re-routing power upon the occurrence of an event. The interruption device may interrupt the flow of power to an external device upon the detection of an event, such as a circuit overload or short circuit. Interrupting the flow of power may cause power to be cut off to a receiving connector, which supplies power to the external device, by re-routing the flow of power away from the receiving connector by the use of relay switches. By interrupting and re-routing the flow of power, an electrical fire, damage to the external device or other hazard may be prevented. Once the source of the problem, such as a defective external device, has been removed or fixed, the flow of power may be re-routed back to the receiving connector.

Abstract: 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.

Abstract: An apparatus and method for a supervisory circuit for a ground fault detection device or a ground fault circuit interrupt (GFCI) device is disclosed in which a low voltage DC power supply is used to generate a test stimulus signal for a self test of the GFCI device. The GFCI device includes line and neutral conductors configured to connect an AC power source and a load. A differential current transformer includes a toroid, through which the line and neutral conductors pass, and a secondary winding wound on the toroid. A differential ground fault detector is electrically connected to the secondary winding of the differential current transformer to compare current generated in the secondary winding from an imbalance of magnetic flux in the toroid to a trip threshold. A wire conductor is routed through the toroid of the differential current transformer. A controller is configured to control a low voltage DC test stimulus signal to be generated in the wire conductor.

Abstract: An arc fault circuit interrupter is disclosed. This arc fault circuit interrupter can include any one or more of three different sensors such as a high frequency sensor, and any one of lower frequency sensors such as a current sensor or a differential sensor. The arc fault circuit interrupter can be configured as an in line arc fault circuit interrupter installed in a wall box. In addition, the arc fault circuit interrupter can include a processor configured to determine any one of a series arc fault, or a parallel arc fault.

Abstract: A circuit protection system has a normal mode, and a maintenance mode with reduced potential arc flash energy. A downstream circuit breaker is mounted within a first enclosure comprising a first access panel. A locking mechanism locks the first access panel closed. An upstream breaker is mounted within a second enclosure comprising a second access panel. A current sensor senses current and is in communication with an electronic trip unit that controls current interruptions by the upstream breaker based on a trip setting. A user interface device is accessible when second enclosure is closed, and allows user selections of normal and maintenance modes. When maintenance mode is selected, the trip unit changes the trip setting such that potential arc flash energy is reduced. The system is configured to keep the first access panel locked closed based on normal mode being selected, and allow unlocking based on maintenance mode being selected.

Abstract: A current leakage protection circuit includes a first input terminal, a second input terminal for receiving a power voltage and a current leakage detection terminal configured for detecting a current leakage from an electronic device. A control circuit of the current leakage protection circuit is configured for providing a control signal to control a first switch circuit to switch off a first connection between the first input terminal and a first output terminal and to control a second switch circuit to switch off a second connection between the second input terminal and a second output terminal when the current leakage detection terminal detects current leakage of the electronic device.

Abstract: An aspect of the present disclosure relates to a system, which may include a faceplate and an electrical receptacle or switch. The faceplate may include a panel having a first surface, a second surface, and an opening defined in the panel providing communication between the first and second surfaces. The faceplate may also include an interrupter extending from the first surface of the panel having at least two interrupter contacts thereon and a first electrical circuit operatively coupled to the interrupter contacts. The electrical receptacle or switch may include a housing and a second electrical circuit, wherein the second electrical circuit is in communication with the first electrical circuit when the faceplate is mounted on the electrical receptacle or switch and the interrupter is configured to interrupt the second electrical circuit.

Abstract: A circuit breaker for an electric load includes first and second terminals; a number of first separable contacts each electrically connected between one of the first terminals and one of the second terminals; a first mechanism to open, close or trip open the first contacts; a number of second separable contacts each electrically connected in series with a corresponding one of the first contacts; a second mechanism to open or close the second contacts; a processor to cause the second mechanism to open or close the second contacts, annunciate through one of the second terminals a power circuit electrical parameter for the electric load, receive from a number of the second terminals a confirmation from or on behalf of the electric load to cause the second mechanism to close the second contacts, and determine a fault state operatively associated with current flowing through the second contacts.

Abstract: A data cable between two electronic devices includes a first interface comprising a first metal shell and a ground end; and a second interface connected to another electronic device comprising a second metal shell, a ground end and an identification end. The data cable includes a detection circuit detecting voltage difference between the first metal shell and the ground end, and the detection circuit comprises an output end connected to the identification end of the second interface. An electronic device using the data cable detects any current leakage in an external electronic device. When the host has current leakage, the electronic device cuts power from the host and prevents data exchange, preventing damage or loss.

Abstract: A power distribution system (that can detect an unsafe fault condition where an individual or object has come in contact with the power conductors) regulates the transfer of energy from a source to a load. Periodically, the source controller opens an S1 disconnect switch, a and load controller opens an S2 disconnect switch. A capacitor represents the capacitance across the load terminals. If the capacitor discharges at a rate higher or lower than predetermined values after the S1 and S2 disconnect switches are opened, then a fault condition is registered, and the S1 and S2 switches will not be commanded to return to a closed position, thus isolating the fault from both the source and the load.

Abstract: A system and associated components for providing an intelligent circuit breaker being adapted to communicate with, monitor and control various devices within a commercial or residential premises. In one embodiment, the system is adapted for low cost, ease of installation and operation, and ease of manufacture. The intelligent circuit breaker may also be adapted to send data relating to sensed parameter or conditions to, and receive commands from, a user interface. Methods for operating such breakers and converting existing circuit breakers to intelligent circuit breakers consistent with the aforementioned system and components are also described.

Abstract: Certain embodiments of the invention may include systems and methods for determining electrical faults. According to an example embodiment of the invention, a method is provided for determining electrical faults. One method can include providing switch circuitry including at least one first switch detector resistor in parallel communication with at least one switch; providing terminal board circuitry including at least one terminal board resistor in parallel communication with the switch circuitry and in communication with a power source; receiving a power source reference; comparing a field voltage value to a generated reference voltage value, generating a comparison value output based at least in part on the comparison of the field voltage value and the generated reference voltage; and determining one of a plurality of field conditions based at least in part on the comparison value output.

Abstract: The present disclosure provides a safe quick disconnect leakage protector, including a power supply circuit, a sampling circuit, a couple of single-pole single-throws, an on and off control circuit, and a testing circuit. The sampling circuit collects the leakage current signal between the live wire and the neutral wire and outputting the leakage current signal; the main control circuit receives the leakage current signal outputted from the sampling circuit, amplifies the leakage current signal, and outputs a grounding failure control signal when the leakage current reaches the predetermined value; the on and off control circuit receives the grounding failure control signal outputted from the main control circuit and controls the single-pole single-throw switches to disconnect the load from the external power supply according to the grounding failure control signal, thereby protecting the load and improves the safety of the leakage protection of an electrical appliance.

Abstract: An apparatus includes an accessory module for a ground monitor that monitors current in a pilot conductor and/or a grounding conductor, which is in a power cable assembly connecting a power source and load. The pilot conductor injects a signal in the grounding conductor. The accessory module includes signal connectors that include multiple connection points. Each connection point provides access to a signal within the ground monitor. The connection points access signals for an output of a circuit monitoring current in the pilot conductor or ground return, a circuit responding to a peak current in the pilot conductor or ground return transitioning below a threshold, a circuit responding to an average current in the grounding conductor transitioning below a threshold, and/or a circuit indicating trip status of a contact in the power source. The connection point signals are in addition to signals from the ground monitor to the power source.

Abstract: An apparatus includes a resistor assembly with resistors connected in series between a first terminal and a second terminal of a pilot conductor and/or a ground return of a ground monitor. The pilot conductor injects an electrical signal in a ground of a power cable assembly. A zener diode assembly is connected between a zener connection point and the ground return. The zener connection point is the first or second terminal. The zener diode assembly includes zener diodes connected in series between the zener connection point and the ground return and is sized to clamp a voltage from the zener connection point to the ground return to a value less than a zener threshold voltage. The zener threshold voltage is set above a nominal voltage on the pilot conductor. The components of the apparatus are spaced to prevent an arcing fault current for voltages less than 3000 V.

Abstract: This document discusses, among other things, a self-test (ST) ground fault circuit interrupter (GFCI) monitor configured to generate a simulated ground fault starting in a first half-cycle of a first cycle of AC power and extending into a second half-cycle of the first cycle of AC power, wherein the first half-cycle of the first cycle of AC power precedes the second half-cycle of the first cycle of AC power. Further, the ST GFCI monitor can detect a response to the simulated ground fault.

Abstract: A circuit breaker (such as a miniature circuit breaker) that wirelessly communicates state and fault information to a main energy monitoring module. The wireless circuit breaker includes a transceiver and a power supply that harvests energy inductively from the line current conductor without the need for a connection to a neutral conductor. The wireless circuit breaker can be implemented in the same package as existing circuit breakers, eliminating the need to replace the panel when upgrading to a system that employs a main energy monitoring module. The wireless circuit breaker can also include an energy storage device for supplying power to the circuit breaker after it has tripped, allowing the circuit breaker to transmit information after a trip. The main energy monitoring module includes a processor and a gateway for evaluating and transmitting information received from the circuit breaker to other applications, such as webpages and smartphones.

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

Abstract: A system and method of dynamically estimating the short circuit current availability (SCCA) at a node in an alternating current electrical distribution system by examining the spectral composition of current drawn by a direct current charging circuit connected to the node. A correlative relationship between the total harmonic current distortion (THDi) in the current drawn by the charging circuit and the SCCA at the node is established for a particular charging circuit. An estimation of the SCCA at the node is accomplished by taking current measurements of current drawn by the charging circuit, analyzing those current measurements to determine the THDi, and estimating a corresponding value of SCCA based on the determined THDi. A method is also provided for calibrating a particular charging circuit to have a reactance and resistance suitable for use in estimating SCCA.

Abstract: An electrical power converter for converting power from a bipolar DC source to supply an AC load is disclosed. For one such embodiment the bipolar DC source is a photovoltaic array and the AC power is sourced into an electric power grid. The bipolar photovoltaic array has positive and negative voltage potentials with respect to earth ground. The converter is a utility interactive inverter which does not require an isolation transformer at the electric power grid interface. Embodiments of the invention include methods of detecting and interrupting DC ground faults in the photovoltaic array.

Abstract: Gate drive circuits for use with semiconductor switching devices are provided. The gate drive circuits include a gate resistor of the semiconductor switching device; a resistance control module in series with the gate resistor of the semiconductor switching device, the resistance control module being configured to provide a first resistance that controls electromagnetic interference under normal operating conditions; and a second resistance during abnormal events; and an abnormal event detector coupled to the resistance control module, the abnormal event detector configured to detect an abnormal event and send an abnormal event signal to the resistance control module responsive to detection of the abnormal event. The resistance control module is configured to provide the second resistance by shorting the resistance provided by the resistance control module responsive to the abnormal event signal to provide increased gate drive and reduced switching losses during the abnormal event.

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.