A fault monitoring device may monitor and detect for faults corresponding to a high-side voltage rail, to low-side voltage rail, or internally within a voltage source connected to the high-side voltage rail and the low-side voltage rail. The fault monitoring device may determine sample voltage levels and/or sample resistance values to detect the faults. Also, in various embodiments, the fault monitoring device may perform one or more fault monitoring processes over multiple stages. The fault monitoring device may determine the sample voltage levels and/or the sample resistance values while switching a secondary resistance circuit in different states over the multiple stages.

A fault monitoring device may monitor and detect for faults corresponding to a high-side voltage rail, to low-side voltage rail, or internally within a voltage source connected to the high-side voltage rail and the low-side voltage rail. The fault monitoring device may determine sample voltage levels and/or sample resistance values to detect the faults. Also, in various embodiments, the fault monitoring device may perform one or more fault monitoring processes over multiple stages. The fault monitoring device may determine the sample voltage levels and/or the sample resistance values while switching a secondary resistance circuit in different states over the multiple stages.

A diagnostic device includes electrical connectors, load, power supply, switching circuitry, sensors, and processor. The connectors include first and second sets of terminals for connecting to the conductors of a branch circuit in an upstream and downstream direction, respectively, at an outlet location along the circuit. The switching circuitry can isolate the upstream and downstream sections of the circuit from the outlet location, and selectively connect or disconnect the power supply or the load to the upstream or downstream section. The sensors measure electrical characteristics on the conductors of the circuit to monitor load currents, such as on power, neutral and ground lines, of the upstream and downstream circuit sections. The processor controls the switching circuitry, and obtains diagnostic information corresponding to the monitored load currents on the upstream and downstream sections of the branch circuit, from the measurements performed by the sensors.

A method for monitoring insulation in a motor drive circuit configured to convert DC power from a power source to AC power to drive a motor. The method includes boosting a DC link voltage of an inverter of the motor drive, isolating the motor drive circuit from the power source; performing at least one isolation test by providing a current path through components of the motor drive and preferably a motor connected to the output of the inverter to be tested; and monitoring the current during each isolation test to detect partial discharge or excessive leakage from the current path, thereby indicating that there exists defects in the insulation in the current path.

A method for monitoring insulation in a motor drive circuit configured to convert DC power from a power source to AC power to drive a motor. The method includes boosting a DC link voltage of an inverter of the motor drive, isolating the motor drive circuit from the power source; performing at least one isolation test by providing a current path through components of the motor drive and preferably a motor connected to the output of the inverter to be tested; and monitoring the current during each isolation test to detect partial discharge or excessive leakage from the current path, thereby indicating that there exists defects in the insulation in the current path.

A system for evaluating a high voltage asset (HV asset) comprises a PD detector disposed in the HV asset. The PD detector comprises an electrical coupler configured to couple electrical disturbances indicative of a partial discharge from a high voltage conductor of the HV asset to an electrical-to-optical converter. The electrical-to-optical converter comprises a light emitter, and is configured to convert the electrical disturbances to a light signal. An optical power receiver is disposed in the high voltage asset and coupled to the PD detector. The optical power receiver is configured to receive optical power from an external optical power source via a non-conducting optical fiber arrangement. The electrical-to-optical converter is configured to communicate the light signal indicative of the partial discharge to an electronic device external of high voltage asset via the non-conducting optical fiber arrangement.

Systems, methods, and apparatus for corona detection using audio data are provided. In one example embodiment, the method includes obtaining, by one or more computing devices, audio data indicative of audio associated with an electrical system for at least one time interval. The method includes partitioning, by the one or more computing devices, the audio data for the time interval into a plurality of time windows. The method includes determining, by the one or more computing devices, a signal indicative of a presence of corona based at least in part on audio data collected within an identified time window of the plurality of time windows relative to audio data collected for a remainder of the time interval.

A method for monitoring the electric insulation status of a piece of equipment for a medium-voltage or high-voltage electric system, which includes the following steps: acquiring detection data indicative of the behaviour of said piece of equipment, said detection data including a time sequence of measured discharge values related to partial-discharge events observed at subsequent observation instants in time; basing on said detection data, calculating stochastic data indicative of the electric insulation status of said piece of equipment, said stochastic data including probability values related to the observed partial-discharge events and calculated as a function of one or more characteristic parameters related to said partial-discharge events; basing on said stochastic data, calculating estimated data indicative of said one or more characteristic parameters related to said subsequent observation instants.

The present disclosure includes: a signal generation unit for applying a pulse signal to an electric line; a signal measurement unit for measuring the voltage of an applied pulse signal from the ground, when the pulse signal is applied to the ground through insulation resistance; an average voltage calculation unit for calculating the average voltage of the voltages measured during a period depending on sampling intervals; and a control unit for calculating the sampling intervals on the basis of an initial sampling interval and a preset time multiple, calculating the average voltage during the sampling period according to the calculated sampling intervals, and, according to whether the difference between a calculated first average voltage and a second average voltage measured before the first average voltage is within a first error range, detecting the first average voltage as a normal voltage, or calculating the sampling intervals by applying different time multiples thereto.

A monitoring device is disclosed that is configured to monitor conditions within an electrical enclosure containing electrical equipment. The monitoring device comprises a support configured to couple to an interior surface of the electrical enclosure. The support is configured to hold and electrically couple a plurality of sensors, at least two RF antennas, at least one processor in communication with the plurality of sensors and the at least two RF antennas, and a power connection configured to receive electrical and Ethernet input. The at least one processor is configured to receive and analyze data obtained from the plurality of sensors and the at least two RF antennas pertaining to a plurality of conditions inside the electrical enclosure. The at least one processor is configured to detect a potential electrical equipment failure based on the received an analyzed data.