Abstract: Systems and methods for network failover in digital substations are provided. One method includes receiving, by an intelligent electronic device (IED) from a process interface unit (PIU), in parallel a pre-configured data stream via a point-to point connection and one or more other data streams via an Ethernet network. The method further includes determining that at least one of the following failure conditions is satisfied: a frame in the pre-configured data stream is lost or delayed, quality of the data in the frame in the data stream is below a first threshold, period of the time associated with the data in the frame in the data stream is below a second threshold, or a health indicator associated with the PIU is below a third threshold. The method further allows identifying at least one redundant frame in the one or more other data streams. If the quality of data in redundant frame is satisfactory, the method proceeds to use the redundant frame for further processing.

Abstract: Techniques for reducing interference with sensor (light) signals and measurement in polarimetric fiber optic sensors from undesired effects of current and vibrations on light signals carried in fiber optic cables are presented. A sensor system comprises a first depolarizer associated with a fiber optic cable and in proximity to a light source that provides a light signal to such cable. First depolarizer depolarizes the light signal to produce a first depolarized light signal output to another portion of the fiber optic cable that can be wrapped around or associated with a conductor cable or ground cable. To reduce undesired polarizing effects on the first depolarized light signal due to current or vibrations from the conductor cable or ground cable, the system comprises a second depolarizer that depolarizes the (re)polarized light signal to produce a second depolarized light signal suitable for use in sensing current or voltage after additional processing.

Abstract: A system and method is disclosed for recovering reagents that are used in removing contaminants from a flue gas stream. The system and method includes contacting the flue gas stream with reagents such as ammonia and sulfuric acid to create an ammonium sulfate stream. The ammoniated sulfate stream is forwarded to an electrodialysis unit wherein the reagents are regenerated and recirculated back to the system.

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: The present invention relates to a method of monitoring oscillations that are liable to interact in an electrical power network, in dependence on measurement of AC waveforms in the electrical power network. The method comprises receiving first waveform data corresponding to an electrical quantity in each phase of at least two phases of three-phase AC waveforms at a location in the electrical power network. The method further comprises applying a transformation to the first waveform data to provide therefrom second waveform data corresponding to an electrical quantity at the location in a single phase representation, the second waveform data depending on the at least two phases.

Abstract: Exemplary embodiments described in this disclosure can pertain to a controller apparatus that provides control signals to a power generation unit. The controller apparatus can include a first controller, a second controller, and a supervisor that can place the first controller in an in-service state and the second controller in a standby state. The first controller provides control signals to the power generation unit when in the in-service state. The second controller can include a copy of an application program contained in the first controller. This copy of the application program can be modified or replaced while the second controller is in the standby state. The supervisor may then opt to place the second controller in the in-service state and place the first controller in the standby state. The switch-over of controllers is carried out in a substantially simultaneous manner that eliminates interruption in control operations.

Abstract: A medium-voltage or high-voltage electrical device comprising a sealed enclosure in which are located electrical components covered with a solid dielectric layer and a gaseous medium ensuring electrical insulation and/or extinguishing electrical arcs, the gaseous medium comprising heptafluoroisobutyronitrile and a dilution gas, the thickness of the solid dielectric layer being less than 1 mm and being produced from a material comprising a polyepoxide or polyurethane resin optionally containing a filler or aluminum oxide.

Abstract: The present application provides a rotor for use in a turbine engine. The rotor may include a first rotor disc, a second rotor disc adjacent to the first rotor disc, and a belly band seal positioned between the first rotor disc and the second rotor disc. The belly band seal may include a band seal with a locking tab brazed thereon.

Abstract: Embodiments of the disclosure can include systems and methods for providing a seismic support structure for electrical equipment, including low voltage or high voltage electrical equipment and power transmission equipment, to be supported above a surface, such as the ground or a foundation.

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 an electrical assembly for use in a power transmission network. The electrical assembly includes a converter including terminals for connection to an electrical network, where the first terminal is a DC terminal. The assembly also includes a DC power transmission medium connected to the DC terminal, and a circuit interruption device including switching element(s) and an energy absorption element, each switching element being switchable to divert a flow of current in the DC power transmission medium through the energy absorption element in order to reduce the flow of current in the DC power transmission medium; The assembly also includes a converter control unit programmed to operate the converter to control a DC voltage at the DC terminal in a leakage current reduction mode to control a voltage across the energy absorption element.

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: Various embodiments described in this disclosure pertain to methods and systems for detecting and evaluating oscillations in an electrical power grid. The oscillations can include one or more oscillatory conditions, which can occur in one or more of five predefined frequency bands. Each of the five predefined frequency bands is categorized at least in part, by oscillations that are originated by uniquely different sources. In one embodiment, an oscillation detector can be used to detect the oscillatory condition and determine a magnitude characteristic, a phase characteristic, and/or a damping characteristic of at least one oscillation frequency that contributes to the oscillatory condition.

Abstract: Embodiments of the disclosure relate to an electric switching unit provided with an arc-blasting unit. In one embodiment, an electric switch can be provided. This electric switch can include an arc-blasting unit with a compression cylinder enclosing a compression chamber mobile together with the mobile contacts, and a stationary piston at an end of the compression chamber, provided with a support rod made up as a blowpipe which channels the gas compressed in the chamber when the contacts separate to a nozzle that directs the flow to a separation place of the contacts so as to efficiently blast electric arcs. The arrangement can be relatively lightweight and can occupy relatively little space.

Abstract: A wet scrubber (14) useful for reducing flue gas sulphur oxides and particulate matter comprising an at least first spray level arrangement (34) arranged horizontally in a wet scrubber tower (16). The at least first spray level arrangement (34) may comprise downwardly, upwardly, and/or combination downwardly and upwardly spraying nozzles (40). Arranged between the nozzles (40) is a plurality of single plates (76, 76A) and/or double plates (82) to direct flue gas flow into absorbent liquid or slurry atomized by the nozzles (40) for flue gas sulphur oxide and particulate matter reduction.

Abstract: A converter (30) comprises first and second DC terminals (32,34) connectable in use to a DC network (40), the converter (30) including a converter limb (36) extending between the DC terminals (32,34), the converter limb (36) including first and second limb portions separated by an AC terminal (38), the AC terminal (38) connectable in use to an AC voltage, each limb portion including at least one director switch (44) connected in series with a waveform synthesizer between the AC terminal (44) and a respective one of the first and second DC terminals (32,34), the waveform synthesizers operable to control the modulation of an AC voltage waveform at the AC terminal (38), each director switch (44) operable to switch the respective waveform synthesizer into and out of circuit between the respective DC terminal (32,34) and the AC terminal (38); and a controller (56) programmed to selectively control the switching of the director switches (44) to switch both of the limb portions into circuit concurrently to form a cu

Abstract: A support structure for a HVDC disconnector is disclosed. The support structure comprises a support insulator having a body enclosing a chamber; an insulating gas provided in the chamber; and a first flange and a second flange positioned at opposite ends of the support insulator. A rotating insulator may be positioned in the chamber.

Abstract: An automated system for manipulating a workpiece includes a machining device, a locating device configured to determine a position of a workpiece, and a positioning system operatively connected to the machining device and being configured to adjust a position of the machining device to align a centerline of the machining device with a longitudinal axis of the workpiece, based upon the determined position of the workpiece. The machining device includes a stabilizing mechanism to engage the workpiece to maintain the workpiece in the determined position, and a cutting element for performing a machining operation on the workpiece.

Abstract: A system for remote control of locomotives over a single time division multiple access network is provided. The system includes a locomotive control unit configured to operatively control a locomotive. The locomotive control unit is suitable for transmitting and receiving information via the network. The system also includes at least two operator control units suitable for transmitting and receiving information via the network and a hump control unit suitable for transmitting and receiving information via the network. The network employs both spatial and frequency diversity for remote control. The locomotive control unit, the at least two operator control units, and the hump control unit will only transmit in a respective defined period of time.

Abstract: A method for preheating a beater mill is provided. The method includes: rotating a beater wheel disposed within the beater mill to facilitate circulation of a gas stream between the beater mill and a furnace fluidly connected to each other via both a pulverized fuel conduit and a flue gas recirculation conduit; generating a burner gas via a burner disposed within the flue gas recirculation conduit such that the burner gas joins and heats the gas stream circulating through the beater mill and the furnace; and adjusting at least one of an air supply and a fuel supply to the burner via a controller based at least in part on one of a temperature of the gas stream at an entrance of the beater mill, a temperature of the gas stream at an exit of the beater mill, and an oxygen level within the beater mill.