In a line to line fault detection and protection system, a source end power supply supplies power to a remote load over a transmission line and monitors the dynamic behavior of a transmission line power characteristic. If that dynamic behavior is outside a constraint that is actively imposed on the transmission line dynamic behavior by a load end power conditioning system, a possible line to line fault is recognized. The preferred power characteristic is current and the preferred constraint is a maximum rate of change of current drawn from the transmission line by the load end power conditioning system.

A motor control apparatus for controlling a power supply to an electrical motor (M) connected to an output terminal (3) of the motor control apparatus (1) comprising: an overcurrent protection circuit (1A) having a power switch (5) through which the electrical motor (M) receives an electrical load current (I.sub.L) and having a sensor component (4) connected in series with the power switch (5) and adapted to generate directly a voltage drop (ΔU.sub.4) corresponding to the current rise speed of the electrical load current (I.sub.L) flowing from an input terminal (2) of the motor control apparatus (1) via the sensor component (4) and the power switch (5) to the output terminal (3) and having a driver circuit (6) adapted to detect an occurring overcurrent depending on the voltage drop (ΔU.sub.4) generated by the sensor component (4) and/or depending on a voltage drop (ΔU.sub.5) along the power switch (5) and adapted to switch off said power switch (5) upon detection of an overcurrent within a switch-off period of less than one millisecond; and/or comprising a power supply control circuit (10) having a sensor component (9) adapted to measure at the input terminal (2) a supply voltage notified to a control unit (8) of the motor control apparatus (1) adapted to control an electrical power supplied to the electrical motor (M) depending on an operation mode of the electrical motor (M).

A system and method for nuisance-trip decision management in an electric power system using data analytics comprising, a protection system, PS, and at least one electrical protection circuit, EPC. The PS comprising, a plurality of sensors configured to measure data; a memory configured to store an updated data of nuisance-trip events and a plurality of nuisance-trip parameters detected or generated on the electric power system over a period; a processor configured to perform hybrid machine learning (HML) based on the measured data from the plurality of sensors for a nuisance-trip condition and communicate with a neighboring PS; a protection microcontroller configured to allow or avoid tripping at least one electronic tripping circuit provided in the at least one EPC by communicating with the processor and the neighboring PS.

A power converter includes a power conversion circuit having a first terminal set and a second terminal set, configured to convert power input via one of the first terminal set and the second terminal set and output the converted power via the other of the first terminal set and the second terminal set; a measurement unit; a controller configured to control the power conversion circuit to generate a voltage/current waveform travelling along the first network with a power supplied by a second power source linked to the second terminal set of the power conversion circuit in response to a condition that a change rate of the measurement of the voltage/current exceeds a threshold; and locate a fault on the first network. The power conversion circuit can be re-used for different modes of operation either for power transmission under normal condition or for fault location under fault condition.

A method of detecting a serial arc fault in a DC-power circuit includes injecting an RF-signal with a narrow band-width into the DC-power circuit and measuring a response signal related to the injected RF-signal in the DC-power circuit. The method further includes determining a time derivative of the response signal, analyzing the time derivative, and signaling an occurrence of a serial arc fault in the power circuit based on the results of the analysis. A system for detecting an arc fault is configured to perform a method as described before.

A power system comprises a power source, a transmission line coupled to the power source through a circuit breaker, a shunt reactor coupled to the transmission line, and a current transformer connected in series with the shunt reactor. A method for controlling the circuit breaker of the power system comprises processing an output signal of the current transformer to obtain the voltage on the transmission line by determining a time derivative of a current sensed by the current transformer. The method further comprises performing, by at least one control or protection device, a control or protection operation (e.g., auto-reclosing) based on the determined time derivative of the current sensed by the current transformer.

A power system comprises a power source, a transmission line coupled to the power source through a circuit breaker, a shunt reactor coupled to the transmission line, and a current transformer connected in series with the shunt reactor. A method for controlling the circuit breaker of the power system comprises processing an output signal of the current transformer to obtain the voltage on the transmission line by determining a time derivative of a current sensed by the current transformer. The method further comprises performing, by at least one control or protection device, a control or protection operation (e.g., auto-reclosing) based on the determined time derivative of the current sensed by the current transformer.

A method of detecting a serial arc fault in a DC-power circuit includes injecting an RF-signal with a narrow band-width into the DC-power circuit and measuring a response signal related to the injected RF-signal in the DC-power circuit. The method further includes determining a time derivative of the response signal, analyzing the time derivative, and signaling an occurrence of a serial arc fault in the power circuit based on the results of the analysis. A system for detecting an arc fault is configured to perform a method as described before.

Presented herein are techniques for power fault management that operates without power-source-side switching. A power transmitter is configured to provide power to a current loop, and a power receiver is configured to receive the power from the current loop. The power receiver is configured to, on a periodic basis, disconnect from the current loop to stop pulling power from current loop for a period of time to enable a safety check to be performed by the power transmitter. The power transmitter is configured to monitor current on the current loop, determine whether the current level on the current loop passes the safety check within a predetermined time interval since a determination that the current level was not within a safe range, and control connectivity of the power to the current loop based on whether the safety check has or has not passed within the predetermined time interval.

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.