Abstract: A system for dynamic rating of a power grid may include a plurality of terminal units, and a controller. The terminal units may detect a voltage phasor and a current phasor at nodes of the power grid. The controller may, based on the voltage phasors and the current phasors of the plurality of nodes, determine a dynamic thermal stability power rating for each line, a dynamic angular stability power rating for each node, and a dynamic voltage stability power rating for each node. The controller may, based on the dynamic thermal stability power rating, the dynamic angular stability power rating, and the dynamic voltage stability power rating, determine a dynamic system rating for the power grid. The controller may control the power grid in response to the dynamic system rating.

Abstract: Systems, methods, and computer-readable media are disclosed for high impedance detection in electric distribution systems. An example method may include calculating, by a processor, a relative randomness of a signal, wherein the relative randomness is a derivative of a first scale wavelet transform divided by an energy of the signal. The example method may also include calculating, by the processor, one or more scales of a wavelet transform of the signal. The example method may also include calculating, by the processor, one or more energy ratios between energy of the wavelet transform in the one or more scales. The example method may also include calculating, by the processor, a zero-crossing phase difference between a third harmonic and a fundamental component of the signal.

Abstract: Systems, methods, and computer-readable media are disclosed for high impedance detection in electric distribution systems. An example method may include calculating, by a processor, a relative randomness of a signal, wherein the relative randomness is a derivative of a first scale wavelet transform divided by an energy of the signal. The example method may also include calculating, by the processor, one or more scales of a wavelet transform of the signal. The example method may also include calculating, by the processor, one or more energy ratios between energy of the wavelet transform in the one or more scales. The example method may also include calculating, by the processor, a zero-crossing phase difference between a third harmonic and a fundamental component of the signal.

Abstract: Systems and methods are provided herein for improving distance protection in transmission lines. Such systems and methods may involve receiving one or more current and voltage inputs, and determining, based on the one or more current and voltage inputs, one or more current and voltage phasors, wherein the one or more current and voltage phasors are determined using a short window phasor estimation. Such systems and methods may also involve determining, within a single power cycle and based on the one or more current and voltage phasors, a fault in a transmission line. Such systems and methods may also involve sending, to a distance protection element and based on the determination that the fault exists, a signal to clear the fault in the transmission line, and clearing the fault in the transmission line.

Abstract: In the field of fault location within a power transmission network, a method of determining a fault location in a power transmission conduit includes: (a) sampling at an original sampling frequency a signal propagating through the power transmission conduit to establish a first data set including a plurality of sampled signal characteristics; (b) interpolating the first data set to establish a second data set including an increased number of signal characteristics whereby the second data set has an equivalent sampling frequency higher than the original sampling frequency; (c) identifying a fault wave signal within the second data set; and (d) utilising the propagation characteristics of the fault wave signal to determine the origin of the fault wave signal within the power transmission conduit.

Abstract: There is provided systems, apparatus, and methods for locating a fault in a plurality of windings of a transformer. In one embodiment, the apparatus may include: a measurement device configured to measure electrical flow parameters of the transformer when the transformer is in an online mode; and a fault location determination unit configured to determine electrical flow parameters of the windings from the measured electrical flow parameters of the transformer, wherein the fault location determination unit is configured to process the determined electrical flow parameters of the windings to determine the location of the fault in the windings.

Abstract: The technology described herein is generally directed towards a system for power transmission system protection and fault location, such as implemented in a deployable device at one or more junction points of a power transmission system. Aspects of the described technology can be directed to analyzing a traveling wave corresponding to a fault on a power transmission system. Example aspects can comprise receiving data representing current and voltage components of a traveling wave, maintaining the data in storage for fault location determination of the fault, transforming the data via a wavelet transform, into wavelet transform results and using the wavelet transform results for protection of the power transmission system.

Abstract: In the field of power system stability there is provided a method of predicting the presence of an out-of-step condition in a power system that includes a plurality of generators, the method including the steps of: (a) obtaining a differential value ({tilde over (?)}COIk) between a rotor angle (?k) of an individual one of the plurality of generators and an equivalent rotor angle (?COIk) of the centre of inertia of the remainder of the plurality of generators; (b) processing the differential value ({tilde over (?)}COIk) to determine whether the differential value ({tilde over (?)}COIk) is predicted to reach a predefined reference threshold (?threshold); and (c) predicting the presence of the out-of-step condition in the power system if the differential value ({tilde over (?)}COIk) is predicted to reach the predefined reference threshold (?threshold).

Abstract: A DC distance protection controller for identifying a fault within a protection zone that extends between a first terminal and a set point along a DC power transmission conduit which lies between the first terminal and a second terminal within a DC electrical power network. The protection controller periodically obtains as respective sampled pairs a measured voltage value and a measured current value of the DC power transmission conduit; isolates a fault component voltage value and a fault component current value to define a respective corresponding isolated pair; calculates from each isolated pair a fault component operating voltage of the DC power transmission conduit at the set point; compare a given calculated fault component operating voltage with a historical voltage value; and identifies a fault within the protection zone when the given calculated fault component operating voltage is greater than the historical voltage value.

Abstract: The technology described herein is generally directed to a method of locating a fault in a multi-terminal electrical power transmission scheme, such as implemented in a power transmission scheme where each of six terminals is connected with one of four junctions via a power transmission section and each junction interconnects a plurality of power transmission sections. Aspects of the described technology can be directed to measuring the voltage and current at each terminal, calculating from the measured voltage and current at each terminal corresponding voltage and current phasors, determining from the calculated voltage and current phasors a synchronization difference between the measured voltage and current at a designated terminal and the measured voltage and current at each other terminal, modifying the calculated voltage and current phasors to compensate for each synchronization difference, and determining from the compensated voltage and current phasors the location of the fault.

Abstract: In the field of Rogowski coils for the measurement of current within a conductor there is provided an electrical interface for connection to a Rogowski coil arranged around a primary conductor. The electrical interface includes an input that is configured to sample an input voltage signal from the Rogowski coil. The electrical interface also has an integrator circuit which includes an integrator module that is configured to integrate the sampled input voltage signal to provide an output voltage signal from which can be derived a primary current flowing through the primary conductor. The integrator module employs a transfer function that includes an attenuation factor.

Abstract: A trip apparatus for a circuit interruption device that comprises a coil operatively connectable to a circuit interruption device. The coil is configured to selectively operate the circuit interruption device to interrupt when a current flowing through the circuit interruption device exceeds a threshold. The trip apparatus also includes a current measuring device configured to selectively measure a coil current flowing through the coil to determine a measured coil current signal. In addition, the trip apparatus includes a monitoring device configured to determine the derivative of the measured coil current signal and to perform a correlation of the derivative of the measured coil current signal and a reference derivative of a reference coil current signal to determine a correlation output. The monitoring device is further configured to compare the correlation output with a reference correlation threshold to determine whether an operating condition of the coil is normal or abnormal.

Abstract: There is provided a protection apparatus for protecting an electrical network. The protection apparatus comprises: at least one protection device configured to protect the electrical network from a fault in response to a or a respective protection criterion being met; and a controller configured to: receive real-time information on a change in topological structure of the electrical network; perform an online determination of the real-time impedance or admittance matrix of the electrical network based on the change in topological structure of the electrical network; and adapt the or each protection criterion based on the real-time impedance or admittance matrix.

Abstract: Systems and methods are provided herein for improving distance protection in transmission lines. Such systems and methods may involve receiving one or more current and voltage inputs, and determining, based on the one or more current and voltage inputs, one or more current and voltage phasors, wherein the one or more current and voltage phasors are determined using a short window phasor estimation. Such systems and methods may also involve determining, within a single power cycle and based on the one or more current and voltage phasors, a fault in a transmission line. Such systems and methods may also involve sending, to a distance protection element and based on the determination that the fault exists, a signal to clear the fault in the transmission line, and clearing the fault in the transmission line.

Abstract: A method of protecting a power transformer including: monitoring an external fault indication signal; carrying out locally a fault determination; carrying out locally an inrush current determination; and issuing a final trip signal to protect the power transformer if the external fault indication signal identifies that a fault has occurred and the locally carried out fault determination confirms that a fault has occurred; or the external fault indication signal identifies that a fault has occurred and the locally carried out fault determination identifies that no fault has occurred but after a predetermined delay the locally carried out inrush current determination confirms the absence of an inrush current.

Abstract: Systems and methods of determining a communication time delay in electrical power systems are provided. In one embodiment, a method of determining a communication time delay in a communication network between a local terminal and each of a plurality of remote terminals in a multi-terminal multi-junction electrical power system includes: (a) calculating a respective initial communication time delay between each remote terminal and the local terminal; (b) calculating a respective junction time delay between respective first, second and third pairs of adjacent junctions; and (c) correcting the calculated initial communication time delay of each remote terminal spaced from the local terminal by two or more junctions according to each corresponding junction time delay arising between the or each remote terminal and the local terminal.

Abstract: There is provided systems, apparatus, and methods for locating a fault in a plurality of windings of a transformer. In one embodiment, the apparatus may include: a measurement device configured to measure electrical flow parameters of the transformer when the transformer is in an online mode; and a fault location determination unit configured to determine electrical flow parameters of the windings from the measured electrical flow parameters of the transformer, wherein the fault location determination unit is configured to process the determined electrical flow parameters of the windings to determine the location of the fault in the windings.

Abstract: There is provided a method of locating a fault in a power transmission scheme. The power transmission scheme includes power transmission sections and a first end connection point, a second end connection point, and at least one intermediate connection point. The method includes (i) measuring first and second end voltage phasors at the first and second end connection points respectively; (ii) obtaining a first set of voltage phasors, which includes the measured first end voltage phasor and includes respective voltage phasors at each of the second and intermediate connection points; (iii) obtaining a second set of voltage phasors, which includes the measured second end voltage phasor and includes respective voltage phasors at each of the first and intermediate connection points; (iv) comparing the first and second sets of voltage phasors to identify the power transmission section or connection point corresponding to the location of the fault.

Abstract: The technology described herein is generally directed towards a system for power transmission system protection and fault location, such as implemented in a deployable device at one or more junction points of a power transmission system. Aspects of the described technology can be directed to analyzing a traveling wave corresponding to a fault on a power transmission system. Example aspects can comprise receiving data representing current and voltage components of a traveling wave, maintaining the data in storage for fault location determination of the fault, transforming the data via a wavelet transform, into wavelet transform results and using the wavelet transform results for protection of the power transmission system.

Abstract: An apparatus for determining a fault location distance or distance protection in a multi-phase power transmission medium, configured to; determine a set of line fault parameters based on a measurement of voltage and current at a point of said power transmission medium and a fault type, the line fault parameters determined at a plurality of sample times determine a derivative with respect to time of a line fault parameters representative of an inductive part of measured faulty phase current; determine a set of phasors using a Fourier transformation of the derivative and of the remaining line fault parameters at the plurality of sample times and use said set of phasors to determine a fault location distance or distance projection distance along the power transmission medium; wherein, the determination of the fault location distance or the distance protection distance is based on the line equation; U . P = U . F + [ R 1 ? I . PR + X 1 ? 0 ? I . PX ] ? D F .