An apparatus and method for detecting a change in electrical properties in a system is disclosed. Embodiments of the disclosure enable the detection of a change in electrical properties in a system by, in response to a load generated on a power delivery network power in at least part of the system, measuring noise induced in the power delivery network in response to the load. Based on the measured noise, a dynamic-response property of the power delivery network is determined and the dynamic-response property is compared to a stored reference dynamic-response property of the power delivery network based on a predetermined load. In the event of a difference between the dynamic-response property and the reference dynamic-response property, a response to the event is triggered to indicate tampering with the power delivery network.

The present subject matter describes fault detection during power swing in a power transmission system. Voltage and current measurements are obtained for each phase at a terminal of the power transmission system. Based on measurements obtained, a value of change in an impedance angle for each phase-to-ground loop and each phase-to-phase loop for each sampled value of voltage and current is calculated, where the value of change in the impedance angle is a difference between impedance angles of two samples separated by a predetermined interval. Further, the average values for change in impedance angle based on a predetermined number of values of the change in the impedance angle for each phase-to-ground loop and each phase-to-phase loop is calculated. The average values calculated are compared with a threshold of change in impedance angle and based on the comparison a fault in one or more of the phase-to-ground loops or phase-to-phase loops is detected and classified.

A wireless tracking device includes circuit components, a battery, and a circuit connecting the circuit components and the battery. The circuit components include a first wireless communication system, a processor, a memory or storage, and a first sensor operable to measure conditions of the wireless tracking device. The wireless tracking device is configured to attach to an overhead electrical line and detect failure events that are experienced by the overhead electrical line based on sensor data monitored by the wireless tracking device.

A method for controlling a power distribution network includes receiving, via an electronic processor, a fault indication associated with a fault from a first isolation device of a plurality of isolation devices. The processor identifies a first subset of a plurality of phases associated with the fault indication and a second subset not associated with the fault indication. The processor sends a first open command to each member of a set of downstream isolation devices for each phase in the first subset. The processor identifies a plurality of tie-in isolation devices to be closed to restore power. Responsive to identifying a first potential loop configuration, for each of the plurality of tie-in devices, the processor sends a close command to the tie-in isolation device for each of the plurality of phases and sends a second open command to the associated downstream isolation device for each phase in the second subset.

Systems, methods, and computer-readable media are disclosed for impedance-based broken conductor detection in electric distribution systems. Upon the detection of a broken conductor, the affected overhead line will be de-energized before it hits the ground. An example method may include determining, during a first time period, a first impedance value measured by a first IED, and may further include determining, during a second time period that after the first time period, a second impedance value measured by the first IED. The method may further include determining a first ratio based on dividing a difference between the first impedance value and the second impedance value by the first impedance value, and may further include determining that the first ratio deviates from a threshold setpoint, and determining that a broken conductor condition occurs based on the first ratio deviating from the threshold setpoint.

It is provided a current recording method, a current recording device and a current recording system by the embodiments of this disclosure. The current recording method comprises: acquiring a first current Fourier value, the first current Fourier value being a Fourier value acquired by Fourier transforming an instantaneous value of current at a first end of a power line; acquiring a second current Fourier value, the second current Fourier value being a Fourier value acquired by Fourier transforming an instantaneous value of current at a second end of the power line; time-alignment the first current Fourier value and the second current Fourier value, based on a first transmission delay for acquiring the first current Fourier value and a second transmission delay for acquiring the second current Fourier value; storing the aligned first current Fourier value and second current Fourier value into a storage.

An electrical circuit for connecting an electrical measurement device (16), which is used to measure partial discharges in a power grid having an operating voltage in the range of 1-69 kV, and which has an A/D converter (17) for converting a measured voltage pulse into a digital signal and has a microprocessor unit (18) for evaluating the digital signal, with a measurement output of a capacitive voltage testing system (3) of switchgear for the power grid having the operating voltage in the range of 1-69 kV. The electrical circuit (8) has a frequency response matching resistor (9) which is connected between an input line (10) for connection to the live pole of the measurement output and to ground, and has a high-pass filter (11) connected down-circuit of the frequency response matching resistor (9).

A method for detecting and locating faulty line on the distribution network circuit based on full waveform information, which uses the current data on the fault occurrence and whole-process operation of the compensation device to effectively solve such common problems as low fault current, poor reliability and low sensitivity in case of single-phase grounding fault to the low-current system through precise GPS synchronization. It improves the sensitivity and reliability of the grounding fault detection, which does not interfere with the system and is applicable to high-resistance grounding.

A system and a method for management of an electric grid. The system includes at least one monitoring server and at least one grid monitoring sensor communicably coupled to the at least one monitoring server. Herein the given grid monitoring sensor is installed to a given electrical utility pole of the electric grid. Each of the at least one grid monitoring sensor includes a magnetic sensor for measuring a time-variant magnetic field induced by current transients in the electric grid.

A powered device (PD) receives a Power-over-Ethernet (PoE) voltage to power the PD over a cable from Power Source Equipment (PSE) configured to output a requested one of multiple candidate PoE voltages to the cable. The PD determines a preferred PoE voltage among the multiple candidate PoE voltages that minimizes a total power loss due to (i) the cable, and (ii) a power loss of the PD that would result if the PD were powered through the cable. The PD requests the preferred PoE voltage from the PSE, receives the preferred PoE voltage from the PSE, and operates at the preferred PoE voltage.