Abstract: A system for readying sub-critical and super-critical steam generator, a servicing method of the sub-critical and the super-critical steam generator and a method of operation of sub-critical and super-critical steam generator is provided. The steam generator includes a first auxiliary heating device disposed on at least one water-steam separator for heating the at least one water-steam separator, and/or a second auxiliary heating device disposed at least on a part of furnace top-end piping for heating the furnace top-end piping. The auxiliary heating devices are heating steam producing components of the steam generator and thus allowing to keep them above the temperature in which materials creating the steam producing components are brittle. The method includes recirculation of the water through the steam generator.

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: A circuit interruption device including first and second terminals for connection, to a respective electrical circuit or network, a current-conductive branch including first, second, and third current-conductive branch portions successively connected in series between the first and second terminals, the first current-conductive branch portion including a first switching element, the second current-conductive branch portion including a second switching element, the third current-conductive branch portion including a third switching element, each switching element configured to be switchable to selectively permit and block a flow of current in the respective current-conductive branch portion, first and second current bypass paths, the first current bypass path connected across the first and second current-conductive branch portions, the second current bypass path connected across the second and third current-conductive branch portions, and a controller configured to selectively control the switching of the swit

Abstract: A control apparatus is described for controlling a frequency set-point for a first AC network electrically connected to a first HVDC station to regulate active power. The controller has a frequency controller operable in a first mode of operation to determine a frequency set-point for the first AC network based on a measured DC voltage at the first HVDC station. A disturbance detector is configured to monitor the measured value of DC voltage at the first HVDC station for a predetermined characteristic indicative that a variation in measured DC voltage does correspond to a known modulation applied to the DC voltage by a second HVDC station. The frequency controller is configured to determine the frequency set-point for the first AC network based on a measured value of DC voltage if said predetermined characteristic is detected, and to control the frequency set-point to a predetermined default frequency if not detected.

Abstract: A system and method for warmkeeping a steam generator such as a sub-critical steam generator is disclosed. Water extraction piping extracts water from a component of one of the water fill circuits of the sub-critical steam generator. A deaerator heating system having an inventory tank of water mixes the extracted water with the water in the tank, and heats the mix of water to a predetermined temperature level to generate heated deaerated feedwater. Feedwater piping forwards the heated deaerated feedwater at the predetermined temperature level from the deaerator heating system to the water fill circuits of the sub-critical steam generator. The water extraction piping, the deaerator heating system and the feedwater piping operate cooperatively to warmkeep the water fill circuits in accordance with the predetermined temperature level while the sub-critical steam generator is in the unfired stand-by mode of operation.

Abstract: There is provided an apparatus (20) for monitoring a condition of an electrical power transmission medium (22), the apparatus (20) comprising: a signal source (24) for transmitting a signal (30) to travel along the electrical power transmission medium (22); and a monitoring device (26) configured to detect one or more reflected signals (34) in the electrical power transmission medium (22), wherein the monitoring device (24) is configured to use the or each detected reflected signal (34) to determine a change in capacitance of the electrical power transmission medium (22).

Abstract: A bipole power transmission scheme with two independent converts, two power feed and one return conduit. During operation of the bipole power transmission scheme under abnormal conditions, when a return conduit is faulty and unable to provide a return current path, each converter controller is programmed to monitor the first power feed in the first transmission conduit and the second power feed in the second transmission conduit and, if the first power feed in the first transmission conduit and the second power feed in the second transmission conduit differ from one another, at least one converter controller modifies the power infeed from its corresponding power source to reduce the difference between the first power feed and the second power feed.

Abstract: A transceiver system may include a transmitter, a receiver, an antenna port that is connectable to the transmitter or to the receiver, a filter send port, and a filter return port. The filter ports may be antenna-side or receiver-side, and connectable across at least one filter between the antenna port and the receiver. A transceiver apparatus may include a housing including the transmitter, the receiver, a transceiver switch, and a filter switch assembly in a chamber of the housing. The ports may be accessible through a wall of the housing. A method for filtering a signal include switching, in response to a first signal, a receiver or a transceiver of a transceiver system from an unfiltered path connected to the antenna port to a filtered path connected to the antenna port. The method may further include switching, in response to a second signal, the receiver to the unfiltered path.

Abstract: A status indicator for a capacitor may include first and second indicator plates, each respectively defining a first face and a second face visually distinct from the first face. The first face of each of the first and second indicator plates is displayed during nominal operation of the capacitor. The second face of only one of the first and second indicator plates is displayed in response to a partial failure of the capacitor. The second face of each of the first and second indicator plates is displayed in response to a complete failure of the capacitor. A system may include a capacitor, and the status indicator coupled to the capacitor. A method for visually indicating a status of a capacitor may include controlling, by a controller, first and second indicator plates to display selected faces indicating nominal operation, partial failure, or complete failure of the capacitor.

Abstract: In the field of high voltage direct current (HVDC) power transmission networks there is a need for an improved sensor failure detector. A sensor failure detector, for use in HVDC power transmission networks, includes an intelligent electronic device. The intelligent electronic device has a first input to receive in-use a number of first sample values from a first sensor measuring a given operational characteristic, and a second input to receive in-use a number of second sample values from a second sensor measuring the same given operational characteristic. The intelligent electronic device also includes a comparator module that is programmed to compare the first and second sample values with one another, and to establish a sensor failure when the first and second sample values differ from one another by more than a primary threshold for a predetermined first number of samples.

Abstract: There is provided a current control circuit (20) for connection between a first electrical network (42) and a converter, the current control circuit (20) comprising: first and second input terminals (24,26) for connection to the first electrical network (42); first and second output terminals (28,30) for respective connection to converter terminals (46,48) of the converter; first and second switching limbs, the first switching limb interconnecting the first input and output terminals (24,28), the second switching limb interconnecting the second input and output terminals (26,30), each switching limb including a respective switching element (32,34,36,38); a director limb (76) extending between the first and second output terminals (28,30), the director limb (76) including at least one current director element (84) and at least one first resistive element (86), the director limb (76) including an intermediate terminal (82); a second resistive element (88), a first end of the second resistive element (88) ope

Abstract: A method and apparatus for displaying information. The method comprises: determining a field of view of a user viewing an environment via a display of a display device; using the field of view, determining a focal region of interest of the user in the environment; providing a database comprising a list of objects and, for each object, a location of that object in the environment; using the list of objects and a location of the focal region in the environment, identifying one or more of the objects that are at least partially located in the environment in or proximate to the focal region; acquiring information related to the identified one or more objects; generating an image element comprising the acquired information; and displaying the generated image element on the display of the display device through which the user is viewing the environment.

Abstract: A protection circuit, for protecting a whole or part of a HVDC power transmission network, includes a number of sets of sensors, each of which set defines a respective protection zone. The protection circuit also includes a controller that is programmed to evaluate sensor information received from the sensors to determine whether a fault has occurred within a protection zone. The controller is further programmed, in the event of a sensor in a protection zone failing, to dynamically reconfigure the affected protection zone by including a sensor from another protection zone.

Abstract: There is provided a sensor system for use in a high voltage direct current network. The sensor system comprises a plurality of sensor devices, each sensor device configured to obtain a respective sensor measurement, wherein the plurality of sensor devices are configured to generate a serial data unit for transmission to a recipient system, the serial data unit configured to include the plurality of sensor measurements (S1, S2, Sn), the serial data unit further configured to include a plurality of validity indicators (FCS1, FCS2, FCSn), each validity indicator (FCS1, FCS2, FCSn) configured to provide an individual validity status of a respective one of the plurality of sensor measurements (S1, S2, Sn).

Abstract: A pulverized solid fuel nozzle tip assembly with a low contact frame for use with a pulverized solid fuel pipe nozzle is described. The pulverized solid fuel nozzle tip assembly has an outer nozzle tip portion adapted to mount in supported relation with the pulverized solid fuel pipe nozzle, and an inner nozzle tip portion adapted for mounting within the outer nozzle tip portion to have secure tiltable movement. The outer nozzle has supporting surfaces that support surfaces of the inner nozzle tip portion to minimize the tilting forces transmitted to the inner nozzle tip portion during normal furnace operation, enhancing the wear resistance of the pulverized solid fuel nozzle tip assembly. The supporting surfaces of the outer nozzle also eliminate stress cracking to the surfaces of the inner nozzle tip portion that can arise due to thermal growth.

Abstract: An actuating mechanism for a circuit breaker includes a first piston movable in a first cylinder, against the force of a first compressible member, by admitting hydraulic fluid, and a second piston movable in a second cylinder, against the force of a second compressible member, by admitting hydraulic fluid. Hydraulic fluid can transferred from the second cylinder into the first cylinder via an interconnecting fluid passage, and released from the first cylinder via an outlet fluid passage. The first piston is arranged to be connected to a circuit breaker in a switchgear so as to open and close it. Importantly, the first piston is directly mechanically connected to the first compressible member, ensuring that all the energy stored in the compressible member is available to open the circuit breaker.

Abstract: An electrical assembly includes a converter-based electrical device and a transformer for connecting the converter-based electrical device to an AC electrical network, a first transformer side of the transformer connected to the converter-based electrical device, a second transformer side of the transformer for connection to the AC electrical network, the transformer including a number of taps, the transformer including a tap changer operable to selectively connect to the or each tap to modify a turn ratio of the transformer. The transformer includes a controller configured to selectively operate the tap changer in an AC voltage modification mode, responsive to an abnormal operating state of the electrical assembly, to modify the turn ratio of the transformer so as to modify an AC voltage at the first transformer side.

Abstract: The present invention provides a high voltage direct current (HVDC) transmission system (300, 600) comprising: a first station (102) comprising series-connected first and second HVDC converters (110, 130); a second station (104) comprising series-connected third and fourth HVDC converters (150, 170), wherein a neutral node (164) coupling the third HVDC converter (150) to the fourth HVDC converter (170) is coupled to earth; a first transmission line (200) connecting a positive node (114) of the first HVDC converter (110) to a corresponding positive node (154) of the third HVDC converter (150), wherein a first pole (240) of the system (300, 600) comprises the first HVDC converter (110), the third HVDC converter (150) and the first transmission line (200); a second transmission line (210) connecting a negative node (138) of the second HVDC converter (130) to a corresponding negative node (178) of the fourth HVDC converter (170), wherein a second pole (250) of the system (300, 600) comprises the second HVDC conve

Abstract: The present application concerns a high-voltage circuit breaker filled with insulating gas having a main axis A, including arcing contacts and an insulating nozzle, wherein an insulating gas flowing from a storage chamber and heated by an electric arc between the two arcing contacts is partitioned into a first gas flow and a second gas flow conducted outside of the insulating nozzle from opposite directions toward a main gas chamber, wherein the first gas flow flows through a first intermediary gas chamber and the second gas flow flows through a second intermediary gas chamber and is partitioned in a first portion directed to the main gas chamber and a second portion directed to an exhaust gas chamber, characterized in that the first portion of the second gas flow is smaller than the second portion of the second gas flow.

Abstract: The present application concerns a circuit breaker including a movable contact, a driving rod slidably mounted in the circuit breaker, a linkage mechanism for driving the movable contact, a pivoted driving fork rotatably mounted in the circuit breaker which cooperates with the driving rod through the cooperation of a primary pin provided on the driving rod and a primary slot provided on the driving fork, a driven lever connecting the driving fork to the movable contact, and wherein the driving rod supports a secondary pin which cooperates with a secondary slot of the driving fork when the driving rod in a position between a predetermined position and an extreme opened position of the circuit breaker.