A bi-directional direct current (DC) solid state power controller (SSPC) architecture and control method. The SSPC protects a DC distribution system by isolating both the positive and negative buses independently in case of short circuit or ground fault. The SSPC architecture includes two self-heal interleaved capacitors and includes a fast, soft-charging control technique that provides line-isolated charging of the DC bulk capacitor to avoid inrush current when powering up the DC distribution system. The soft-charging function alternately charges one of the two interleaved capacitors, while the other capacitor discharges to the DC bulk capacitor. Repetitive switching results in a charging and discharging process that increases the voltage of the DC bulk capacitor prior to powering up the DC distribution system, while keeping the DC power source isolated from the load.

Systems and methods for fault detection and protection in electric power systems that evaluates electromagnetic transients caused by faults. A fault can be detected using sampled data from a first monitored point in the power system. Detection of fault transients and associated characteristics, including transient direction, can also be extracted through evaluation of sample data from other monitored points in the power system. A monitoring device can evaluate whether to trip a switching device in response to the detection of the fault and based on confirmation of an indication of detection of fault transients at the other monitored points of the power system. The determination of whether to trip or activate the switching device can also be based on other factors, including the timing of receipt of an indication of the detection of the fault transients and/or an evaluation of the characteristics of the detected transients.

A high-voltage DC floating system includes a source, a power rail, a power bus, a load, and a pre-charge circuit. The power bus includes a positive bus portion and a negative bus portion. The pre-charge circuit includes a first pre-charge circuit portion that is configured to equalize a voltage across the positive power supply switch between the source and a Y-capacitance of the load and a second pre-charge circuit portion that defines a switched path to ground that is configured to equalize a voltage associated with a Y-capacitance of the negative power rail.

A wiring device including an interrupting device, a fault detection device, and a controller. The interrupting device is configured to place the wiring device in a tripped condition in which the flow of power between one or more line terminals and one or more load terminals is interrupted. The fault detection circuit is configured to detect a fault condition and generate a fault detection signal in response to detecting the fault condition, the fault detection signal being provided to the interrupting device to place the interrupting device in the tripped condition. The controller is configured to monitor a current of the one or more line terminals, identify a presence of an in-rush condition or a steady-state condition, and prevent the output of the fault detection signal upon identifying either the in-rush condition or the steady-state condition.

A power supply apparatus including a protection circuit and a power conversion circuit is provided. The protection circuit includes a control circuit, an auxiliary capacitor, and a switching circuit. The control circuit receives an AC voltage from an AC power source and generates a pulsating voltage and a control signal accordingly. The auxiliary capacitor receives the pulsating voltage and provides a first voltage accordingly. The switching circuit is coupled to the auxiliary capacitor to receive the first voltage and coupled to the control circuit to receive the control signal. The switching circuit transmits the first voltage to the power conversion circuit in response to the control signal. The power conversion circuit converts the first voltage to an output voltage. When the switching circuit is switched to an on state in response to the control signal, the auxiliary capacitor reduces an input inrush current from the AC power source.

A device for controlling a pre-charge current generated when electrically connecting a first terminal and a second terminal, according to one embodiment of the present invention, may comprise: a switch for controlling a magnitude of a current flowing between the first terminal and the second terminal; a first resistor for generating a base voltage of a first transistor in proportion to a magnitude of the pre-charge current flowing between the first terminal and the second terminal; the first transistor for limiting the magnitude of the pre-charge current when a voltage generated by the first resistor is equal to or greater than a predetermined threshold voltage; a photocoupler for receiving, in a state insulated from a first power source, an optical signal from the first power source and supplying power; a capacitor charged by the power supplied by the photocoupler; a second transistor for controlling the magnitude of the pre-charge current on the basis of a charging voltage of the capacitor; and a second resistor for controlling an operating time of the second transistor along with the capacitor.

A system includes a plurality of field devices electrically connected to a feed-in device configured to provide an electrical energy supply to the field devices. The feed-in device has a monitoring device configured to detect spark generation in the energy supply and, based on this, to switch off the electrical energy supply. The field devices each have an input terminal for connecting a supply line. At least one field device is configured for electrical energy supply to at least one subsequent field device, and for monitoring. The monitoring field device has at least one output terminal for connecting a further supply line, via which the electrical energy can be forwarded to the subsequent field device. The monitoring field device has a monitoring device configured to detect spark generation in the energy supply to the subsequent field device and, based on this, to switch off the electrical energy supply.

A method for identifying a fault event in an electric power distribution grid sector including one or more electric loads and having a coupling node with a main grid, at which a grid current adsorbed by said electric loads is detectable. The method allows determining whether a detected anomalous variation of the grid current, adsorbed at the electric coupling node, is due to the start of a characteristic transitional operating period of an electric load or is due to an electric fault.

Disclosed are a household appliance, an apparatus and a method for detecting an arc fault in the household appliance. The apparatus includes: a grid current detecting unit, configured to detect a current from a power grid to the household appliance so as to generate a first current detecting signal; a filter protecting unit, configured to perform an attenuation processing on an arc signal in the power grid; a load current detecting unit, configured to detect an actual running current in a load of the household appliance so as to generate a second current detecting signal; and a control unit connected to the grid current detecting unit and the load current detecting unit respectively, and configured to identify and compare the first current detecting signal and second current detecting signal so as to determine a source of the arc fault.

A bi-directional direct current (DC) solid state power controller (SSPC) architecture and control method. The SSPC protects a DC distribution system by isolating both the positive and negative buses independently in case of short circuit or ground fault. The SSPC architecture includes two self-heal interleaved capacitors and includes a fast, soft-charging control technique that provides line-isolated charging of the DC bulk capacitor to avoid inrush current when powering up the DC distribution system. The soft-charging function alternately charges one of the two interleaved capacitors, while the other capacitor discharges to the DC bulk capacitor. Repetitive switching results in a charging and discharging process that increases the voltage of the DC bulk capacitor prior to powering up the DC distribution system, while keeping the DC power source isolated from the load.