A circuit includes a monitor circuit. The monitor circuit includes a nonlinear functional unit configured to receive a current sense signal and to generate a power signal representing the power of the current sense signal. The circuit further includes a first filter configured to receive the power signal and to generate a first filtered signal and a second filter configured to receive an input signal that depends on the current sense signal and to generate a second filtered signal. A comparator circuit is configured to receive the first filtered signal and the second filtered signal and to compare the first filtered signal with a first threshold value and the second filtered signal with a second threshold value. The protection signal is indicative of whether the first filtered signal exceeds the first threshold value or the second filtered signal exceeds the second threshold value.

The present disclosure relates to systems and methods of sag in a power line. In an embodiment, a monitoring device may include a distance sensor and an operating parameter sensor. A processor of the monitoring device may acquire, via the distance sensor, a first distance measurement. The processor may acquire, via the operating parameter sensor, a first operating parameter measurement. The processor may provide an output signal indicating that the power line is sagging when a combination of the first distance measurement and the first operating parameter measurement exceed a first combined distance-operating parameter threshold.

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 direct-current transmission line protection method and system based on pure current characteristics. The direct-current transmission line protection method based on pure current characteristics comprises: collecting, at a moment k.sub.0, a line current i.sub.M(k.sub.0) of an M side of a first direct-current transmission line and collecting, at a moment k.sub.0−t.sub.s, a line current i.sub.M(k.sub.0−t.sub.s) thereof, calculating, according to the line current i.sub.M(k.sub.0) and the line current i.sub.M(k.sub.0−t.sub.s), at a moment k.sub.0, a differential value di.sub.M(k.sub.0) of a current of the side of the first direct-current transmission line, and determining whether the differential value di.sub.M(k.sub.0) of the current meets a protection enabling criteria; and insofar as, at the moment k.sub.0, the differential value di.sub.M(k.sub.0) of the current of the M side of the first direct-current transmission line meets the protection enabling criterion, enabling direct-current protection for the M side of the first direct-current transmission line, collecting a line current i.sub.M(j) of the M side of the first direct-current transmission line at a moment j and collecting, at a moment j−t.sub.s, a line current i.sub.M(j−t.sub.s) thereof, and calculating, according to the line current i.sub.M(j) and the line current i.sub.M(j−t.sub.s), a differential value di.sub.M(j) of the current of the M side of the first direct-current transmission line at the moment j.

A detection scheme for temporary overvoltages and/or ground fault overvoltages in electric power systems is described. Current passing through a surge arrestor component of the power system is monitored. An algorithm for identifying one or more frequency components of the measured current signal is performed to screen out unwanted harmonics. In some embodiments, this is a frequency domain analysis. The frequency component(s) of the current signal is then compared to a calculated pickup current or pickup voltage of the system to determine if system protection steps should be undertaken.

The present disclosure relates to systems and methods of sag in a power line. In an embodiment, a monitoring device may include a distance sensor and an operating parameter sensor. A processor of the monitoring device may acquire, via the distance sensor, a first distance measurement. The processor may acquire, via the operating parameter sensor, a first operating parameter measurement. The processor may provide an output signal indicating that the power line is sagging when a combination of the first distance measurement and the first operating parameter measurement exceed a first combined distance-operating parameter threshold.

Communication enabled circuit breakers and circuit breaker panels are described. Methods associated with such communication enabled circuit breakers and circuit breaker panels are also described. A circuit breaker panel may include a circuit breaker controller and one or more communication enabled circuit breakers. Two-way wireless communication is possible between the circuit breaker controller and the one or more communication enabled circuit breakers.

The present disclosure relates to a method for detecting an electric arc in an electrical system (100), comprising the following steps: a) acquiring a signal (104) coming from at least one sensor (102) detecting acoustic waves in the system (100); b) calculating, using an electronic processing device (106), a first value representative of the error between the signal and a first projection of the signal in a first representation space defined by a first dictionary matrix; b) calculating, using the electronic processing device (106), a second value representative of the error between the signal and a second projection of the signal in a second representation space defined by a second dictionary matrix; and d) determining, from the first and second values, whether an electric arc has been produced in the system.

A thermal monitoring system includes thermal monitoring devices that generate sensor data including thermal images depicting monitored elements (e.g. of an electrical switchgear system). The sensor data for all monitoring devices installed at a local deployment is collected by a gateway device, and relevant data from multiple local deployments is further aggregated by a cloud management system for further analysis. New event triggering rules determining how the thermal monitoring devices filter or record the sensor data are generated based on the aggregated data during a continuous learning process. The system detects patterns in the sensor data for the monitoring devices and/or local deployments as a whole and tracks deviations from these patterns, improving the accuracy of the event detection over time.

The embodiments provide an electrical safety protection device and method for detecting faulty electrical circuits with fault identification, fault classification and alert system wherein the device is installed between the incoming power supply and the electrical appliance, receives incoming power supply through the input switch and is provided to the voltage sense, current sense, high frequency current sense and core balanced transformer components, the output of these sensor components are provided to a filter component and further the filtered voltage values are provided to the microcontroller wherein the microcontroller analyses these received voltage signals, makes calculations and outputs signals to solenoid present in the input switch determining whether to isolate the incoming power supply or not. The solenoid that works as a switch, switches the incoming power supply into ON or OFF state depending upon the voltage values and instructions received and processed by the microcontroller.