A microgrid overcurrent protection device and a method for overcurrent protection of a microgrid. The protection device including a voltage controlled overcurrent detector for detecting an overcurrent above an overcurrent threshold and a phase directional detector arranged for current direction in a downstream or an upstream direction. The overcurrent threshold of the voltage controlled overcurrent detector is set at an upper overcurrent threshold when a measured voltage Vm is above a threshold voltage Vs and set at a lower overcurrent threshold when the measured voltage Vm is below the threshold voltage Vs. The device further includes a timer arranged for generating a trigger signal with a first delay time period when a downstream current direction and an overcurrent are detected and with a second delay time period when an upstream current direction and an overcurrent are detected.

Digital isolator devices, and many other devices, have a maximum device junction temperature, which, if exceeded, may cause device failure and the integrity of the isolation is no longer guaranteed. The use of an electronic fuse, eFuse, arranged in series with the digital isolator, provides a protection scheme for the digital isolator in which current is limited by the eFuse when it is determined that the supply current of the digital isolator exceeds a predetermined threshold that would the cause junction temperature to increase above an absolute maximum rating. As such, the integrity of the digital isolator is preserved in the event of a system fault.

A circuit for detecting faults affecting a power transistor comprises a conditioning circuit, a first fault status circuit, and a fault signaling circuit. The power transistor is turned on and off by assertion and de-assertion, respectively, of an input signal. The conditioning circuit produces a conditioned gate voltage signal from a gate voltage of the power transistor. The first fault status circuit asserts a first fault indication when the conditioned gate voltage signal is greater than a first fault reference voltage during a first interval after the assertion of the input signal. The fault signaling circuit asserts a fault signal in response to the first fault indication being asserted, and de-asserting the fault signal in response to the input signal being de-asserted.

A current detecting device includes a sense resistor through which a sense current corresponding to a consumption current supplied to a load flows, and an A/D converter configured to perform A/D conversion on a voltage drop generated by the sense current flowing through the sense resistor to detect the consumption current. A resistance value of the sense resistor is variably provided.

A circuit breaker distribution system is configured to provide selective coordination. The system comprises a solid-state switch disposed as a main or upstream breaker and a switch with an over current protection disposed as a branch or downstream breaker. The solid-state switch comprises a microcontroller to: allow repeated pulses of current through to the branch or downstream breaker in an event of an overload or short circuit, choose a maximum current limit for the solid-state switch as a “chop level” such that the chop level is chosen higher than a rated current of the solid-state circuit breaker but low enough that the solid-state switch is not damaged from repeated pulses over a period of time needed to switch OFF the branch or downstream breaker, and add a pulse interval which is optimized to a system voltage waveform in that chopped pulses tend to be longer and more effective for de-latching the branch or downstream breaker when they occur in vicinity of a zero crossing of the system voltage waveform and chopped pulses are shorter and less effective near peaks of the system voltage waveform.

A crowbar module includes first and second electrical terminals, a module housing, and first and second crowbar units. The first crowbar unit is disposed in the module housing and includes a first thyristor electrically connected between the first and second electrical terminals. The second crowbar unit is disposed in the module housing and includes a second thyristor electrically connected between the first and second electrical terminals in electrical parallel with the first crowbar unit.

An uninterruptible power supply (UPS) for a three-phase alternating current network, in particular a medium-voltage network, includes an energy storage system, a switch, an LC resonant circuit, which is a series circuit of an inductance and a capacitance, and a control unit for controlling the switch. The switch and the LC resonant circuit are connected in series, and the series circuit of the switch and the LC resonant is arranged between a network feed and the energy storage system which is connected to a load. There is also described a method for operating such a UPS and a corresponding computer program.

An adapter is for a metering assembly. The metering assembly includes an electrical switching apparatus and a socket assembly. The socket assembly has a plurality of jaw members. The adapter includes a base member and a plurality of electrical contacts each coupled to the base member and structured to be mechanically coupled and electrically connected to a corresponding one of the jaw members. Each of the electrical contacts is structured to be electrically connected to the electrical switching apparatus.

A protection device, for operating an electric machine at a converter, comprises a first and second conductor of a DC link, a switching device having a first and second switch, a link capacitor, a load resistor as a precharge and braking resistor, a semiconductor switch and an electrical fuse for protecting the load resistor. The electrical fuse and the first switch are connected in series to the first conductor and to a first resistor connection of the load resistor and to a first power connection of the semiconductor switch. The second switch is connected to the electrical conductor and to a first capacitor connection of the link capacitor and to a second resistor connection of the load resistor. The semiconductor switch is connected by a second power connection to the second conductor and the link capacitor is connected by a second capacitor connection to the second conductor.

A fault-arc identification method, device and apparatus, and a storage medium. The method comprises: performing sampling on a target arc at a high frequency, and obtaining a high-frequency sampling signal (S11); preprocessing the high-frequency sampling signal, and obtaining a processed sampling signal (S12); performing feature extraction on the processed sampling signal, and obtaining a target arc feature (S13); and inputting the target arc feature to a neural network model, obtaining a target output result, and determining, according to the target output result, whether the target arc is a fault-arc (S14). Performing sampling on a target arc at a high frequency can obtain more arc features from the target arc. Moreover, since a neural network model has favorable data classification capability, using a neural network model to perform determination with respect to the target arc can improve the accuracy and reliability of a fault-arc detection result.