Fault isolation and service restoration in an electrical grid are provided. An approach for receiving a notification message including a state of an electrical component on an electrical grid, and determining, by a computing system, a command message including at least one action to take in response to the state of the electrical component, is described. The approach further includes sending the command message to at least one of the electrical component and other electrical components on the electrical grid.

A ground fault monitoring system includes a ground fault interface device including a power interface and a data interface. The ground fault interface device is structured to output power via the power interface and to receive data via the data interface. The ground fault monitoring system also includes a plurality of ground fault devices structured to detect a ground fault on an associated circuit, to output data of the detected ground fault to the ground fault interface device, and to receive power to operate the ground fault devices via power lines. The plurality of ground fault devices are electrically connected in a series connection with the ground fault interface device by data lines and power lines. Each of the ground fault devices is configured to pass through received data and power.

A method of detecting a fault in a power distribution system includes placing a signal on the system at a frequency F.sub.1 and then detecting a change in the signal due to a change in the impedence of the system as a result of a fault wherein the change is one of a change in phase, a change in signal tone, or a change in voltage level at the load. In one embodiment, band reject filters can be used to diminish the signal at the load or source. In another embodiment, the power source can be a periodic pulsed power source and the signal can be placed on the system during an idle phase of the periodic pulsed power.

A method identifies a location of a fault on a faulty line of an electrical power supply network having a plurality of lines, a plurality of inner nodes, and at least three outer nodes. The outer nodes each bound a line and are provided with measurement devices which are used to measure high-frequency current and/or voltage signals. To locate faults, one of the outer nodes is selected as the starting node for the search for the fault location. Starting from the starting node, paths to the other outer nodes are determined, and that those paths on which the fault location could be located are selected. A line on which the fault location could be located, in principle, is identified for each of the selected paths using the respective times at which the traveling waves arrive, and a potential fault location is determined for the respectively identified line.

The fault location of a fault on a line of an electrical energy supply network is determined. First and second current and/or voltage values are measured and provided with a timestamp at the line ends of the line. Following the occurrence of a fault, the timestamped first and second values are used to determine the fault location. Profiles of travelling waves propagating along the line towards the line ends when the fault occurs are determined from the timestamped first and second values at both line ends. The fault location is defined from the profiles of the travelling waves from a time difference with which the travelling waves arrive at the two line ends. The time difference is derived from a pattern comparison of the profiles of the travelling waves determined for the line ends.

The present application proposes a method of locating oscillation sources of wind power integrated system based on energy spectrums. The method include: collecting information of voltage and current at the terminal of each generator and obtaining a dynamic energy curve of each generator over time; choosing the generators whose curve shows an upward trend in the dynamic energy over time curve into alternative generators; obtaining and processing energy spectrums of synchronous generator, DFIG with PLL, and/or an analogical energy spectrum of DFIG with virtual inertia among the alternative generators; selecting generator with maximum proportion of dominant oscillation mode as an oscillation source reference generator; and calculating the similarity coefficients between energy spectrums of each remaining candidate generator and the oscillation source reference generator, determining the oscillation source generators.

A method for identifying a location of a fault in an electrical power distribution network that includes identifying an impedance of an electrical line between each pair of adjacent utility poles, measuring a voltage and a current of the power signal at a switching device during the fault, and estimating a voltage at each of the utility poles downstream of the switching device using the impedance of the electrical line between the utility poles and the measured voltage and current during the fault. The method calculates a reactive power value at each of the utility poles using the estimated voltages, where calculating a reactive power value includes compensating for distributed loads along the electrical line that consume reactive power during the fault, and determines the location of the fault based on where the reactive power goes to zero along the electrical line.

A system for measuring a loss in power between a power transmission side and a power reception side in a high voltage direct current (HVDC) system is provided. The system for measuring the loss in power includes: a first loss measurement unit installed at the power transmission side, and a second loss measurement unit installed at the power reception side, wherein each of the first and second loss measurement units is installed at a location at which a current or voltage is measured, and includes a voltage sensor for measuring a voltage, a current sensor for measuring a current, a GPS module for providing time information on when measurement is performed by the voltage sensor and the current sensor, and a storage unit storing the time information along with a voltage value and a current value measured by the voltage sensor and the current sensor.

Distance protection for electric power delivery systems that include an unconventional source is disclosed herein using apparent impedance independent of memory and cross-phase polarizing. The apparent impedance may be compared with an offset distance operating characteristic. Fault direction is determined by using zero-sequence ground directional logic for phase-to-ground faults. For phase-to-phase faults, fault direction is determined using weak-infeed directional logic. Fault direction may further use incremental quantity directional principles. The distance protection may further determine a faulted loop using voltage logic. The distance protection may select between traditional distance protection and the methods described herein based on the current feeding the fault.

The invention relates to a method and to an electrical protection device for detecting a disconnection of a protective conductor connection with a subsystem in ungrounded and grounded power supply systems and in a grounded power supply system comprising a converter system.

The invention is based on the idea that the disconnection of the protective conductor connection with a subsystem will reduce the sum of the network leakage capacitances of the power supply system by the value of the network leakage capacitance of the subsystem. The necessary distinction between a subsystem in operation having a disconnected protective conductor connection and a shut-off subsystem is made by evaluating the current total power consumed via the power supply system. In the case of a converter system connected to the subsystem, the protective conductor disconnection is detected by examining the leakage current spectra that are characteristic of the converter system.