Disclosed herein are various embodiments of devices and related methods for detecting an electrical arc event using a motor management relay and for suppressing the electrical arc event. The motor management relay may incorporate an optical arc-flash sensor configured to detect an optical event. Control logic may analyze the optical event and determine whether the optical event corresponds to an electrical arc event. When an electrical arc event is detected an instruction may be issued via a control port in communication with the control logic to implement a protective action. According to various embodiments, a plurality of sensors for monitoring electrical characteristics of a motor may also be in communication with the control logic. Input from the sensors may be analyzed in order to determine whether the optical event corresponds to an electrical arc event.

A method and a device for supplying energy to a low-voltage load using an electronic power supply device. The method involves: a) setting the power supply device to be able to provide an output current to the low-voltage load up to a specified peak current value upon demand; b) monitoring the output current (I.sub.L) provided to the low-voltage load by the electronic power supply device to detect an increase of I.sub.L over a threshold (I.sub.N) which is lower than the peak current value, c) if an increase of I.sub.L to an increased output current value higher than I.sub.N is detected, detecting the increased I.sub.L value and ascertaining an output current pulse duration (t.sub.Pulse) based on the increased current value; d) providing I.sub.L at the level of the increased current value for the duration of the ascertained t.sub.Pulse; and e) providing the I.sub.L at the level of I.sub.N after t.sub.Pulse has expired.

A degradation detection circuit may include a degradation unit including multiple delay elements driven by a high voltage for degradation. The high voltage for degradation value may be higher than an operation voltage. The degradation unit may be configured to provide a first delayed signal after passing a test signal through the degradation unit, wherein the test signal retains a pulse for a preset time. The degradation detection circuit may include a reference unit including a plurality of delay elements driven by the operation voltage, and configured to provide a second delayed signal after passing the test signal through the reference unit, a delay setting unit configured to provide a third delayed signal by selectively adding delay elements with respect to the second delayed signal, and a delay checking logic configured to detect a delay of the test signal by comparing the first delayed signal and the third delayed signal.

A power control device includes a communication device configured to be disposed in a borehole and configured to couple electrical power from a power source to a downhole component from a conductor disposed along a borehole string, a circuit breaker system including a first circuit breaker disposed at a connection between the conductor and the downhole component and configured to be closed to connect the downhole component to the conductor, and a controller configured to monitor at least one of a current level and a voltage level at the connection and at the conductor. The controller is configured to control the circuit breaker system and autonomously perform opening the first circuit breaker in response to detecting a deviation in the at least one of the current levels and voltage levels at the connection, to isolate the downhole component from the conductor and the power source.

A power control device includes a communication device configured to be disposed in a borehole and configured to couple electrical power from a power source to a downhole component from a conductor disposed along a borehole string, a circuit breaker system including a first circuit breaker disposed at a connection between the conductor and the downhole component and configured to be closed to connect the downhole component to the conductor, and a controller configured to monitor at least one of a current level and a voltage level at the connection and at the conductor. The controller is configured to control the circuit breaker system and autonomously perform opening the first circuit breaker in response to detecting a deviation in the at least one of the current levels and voltage levels at the connection, to isolate the downhole component from the conductor and the power source.

A reverse fault current interruptor (RFCI) may be employed in one or more locations in an electrical power system. In one example, an RFCI may be installed in a combiner box of a solar power system. The RFCI may include a reverse current detector and a circuit protector such as a circuit breaker, operable in combination to clear a line-line fault in the combiner box. The RFCI enables a reduction of incident energy levels through detection of a reversal in a fault current characteristic of some DC power systems, where a traditional overcurrent protection device (OCPD) (e.g., fuse, breaker) may not trip in the same period of time.

Systems, methods, techniques and apparatuses of power switches are disclosed. One embodiment is a power switch comprising a first reverse blocking integrated gate-commutated thyristor (RB-IGCT); a second RB-IGCT coupled in an antiparallel configuration with the first RB-IGCT; a transient voltage suppressor coupled in parallel with the first RB-IGCT and the second RB-IGCT; and a controller. The controller is structured to determine a direction of a current flowing through the power switch, determine a magnitude of the current flowing through the power switch exceeds a threshold, and turn off the one of the first RB-IGCT and the second RB-IGCT receiving a current flowing in a reverse direction in response to determining the magnitude of the current flowing through the power switch exceeds the threshold.

Systems, methods, techniques and apparatuses of power switches are disclosed. One embodiment is a power switch comprising a first reverse blocking integrated gate-commutated thyristor (RB-IGCT); a second RB-IGCT coupled in an antiparallel configuration with the first RB-IGCT; a transient voltage suppressor coupled in parallel with the first RB-IGCT and the second RB-IGCT; and a controller. The controller is structured to determine a direction of a current flowing through the power switch, determine a magnitude of the current flowing through the power switch exceeds a threshold, and turn off the one of the first RB-IGCT and the second RB-IGCT receiving a current flowing in a reverse direction in response to determining the magnitude of the current flowing through the power switch exceeds the threshold.

Unique systems, methods, techniques and apparatuses of fault location in DC power distribution systems are disclosed. One exemplary embodiment is a DC power distribution system including a plurality of zones each including a DC power distribution line and a protective device. Each protective device structured to sense one or more electrical characteristics of a line and to controllably open a circuit including the line. At least one intelligent electronic device is structured to determine a line inductance based upon electrical characteristics sensed by one or more of the protective devices and to evaluate a location of the line fault based upon the determined line inductance.

Unique systems, methods, techniques and apparatuses of fault location in DC power distribution systems are disclosed. One exemplary embodiment is a DC power distribution system including a plurality of zones each including a DC power distribution line and a protective device. Each protective device structured to sense one or more electrical characteristics of a line and to controllably open a circuit including the line. At least one intelligent electronic device is structured to determine a line inductance based upon electrical characteristics sensed by one or more of the protective devices and to evaluate a location of the line fault based upon the determined line inductance.