Abstract: A method of fabricating electrical core sheet assemblies such as transformer limbs, transformer yokes, and transformer cores, includes the steps of first cutting electrical core sheets, whose main surfaces have been provided with an anti-corrosion layer, into a desired shape. The side surfaces of the cut core sheets are first provided with an anti-corrosion layer, before the cut core sheets are assembled into the desired core sheet assembly.

Abstract: A digital protection and control (P & C) device for a power distribution network, which comprises a computerized control unit comprising a microprocessor. The P & C device, according to the present invention, further comprises an external computerized palmtop computerized device, including a human-machine interface (HMI), which comprises a software communication platform. This software communication platform is aimed at exchanging, by means of a predefined communication channel, data/information related to the software configuration of the HMI and data/information related to the operating status of the P & C device.

Abstract: The present invention provides a digital protection and control (P & C) device for a power distribution network, which comprises a control unit and human-machine interface (HMI) for allowing a user access to the control unit. The control unit comprises a microprocessor that exchanges data information with the HMI. The digital P & C device, according to the present invention, further comprises a user authentication mechanism for regulating the access of a user to the control unit. This user authentication mechanism comprises an electronic authentication device, associable with the mentioned HMI, which stores first predefined data/information. This first predefined data/information comprises at least a user identification code, for establishing the identity of a user; and a user access code, for establishing the access mode of the user to the control unit.

Abstract: A winding for a transformer or a coil having a ribbon electrical conductor and an insulating material layer composed of ribbon insulation material wound jointly to form turns around a winding core. The individual turns of the winding have a predetermined winding angle with respect to a winding axis of the winding core and are disposed such that they partially overlap one another. An insulating layer is inserted between two radially adjacent layers of the turns. Furthermore, a thickness of the insulating layer is locally matched to the voltage difference determined there. In addition, the thickness of the insulating layer is locally matched, the thickness being interchanged in sequence of the method A+B determined there, to the voltage difference between the two relevant radially adjacent layers at the relevant axial point.

Abstract: Curable epoxy resin composition comprising a polyepoxide; an anhydride hardener; a 1-substituted imidazole as catalyst; at least a diol in an amount of from 5 to 50 phr of said polyepoxide; a filler in an amount of from 200 to 600 phr of said polyepoxide and optionally additives. It shows improved crack resistance properties. An improved process for the fabrication of thermoset articles is also disclosed.

Abstract: An electric power distribution switchboard (I) in which one or more functional units are equipped with a switching device compartment (3) that integrates primary and secondary functions. Within the switching device compartment (3) are included, together with the switching device (37), the current and voltage sensors (36), the position sensors for interlocking, a human machine interface (HMI) and an Intelligent Electronic Device (IED) (4) and the related local configuration point (32) to configure the IED (4). The IED (4) realizes functional unit supervision, control, protection, communication and monitoring and acts as a concentrating point of functional unit information and decisions. The switchboard (1) of the invention further comprises power supply section, an I/O section and a communication system.

Abstract: A fault current limiting system includes switching means for providing a fast switching operation; a parallel current path comprising a limiting fuse; and a switching system to automatically replace a blown set of fuses with an unblown set of fuses after a fault current limiting operation has occurred. A method of limiting fault current includes providing a fast switching operation; providing a parallel current path comprising a limiting fuse; and automatically replacing a blown set of fuses with an unblown set of fuses after a fault current limiting operation has occurred.

Abstract: A digital multifunction relay, for controlling one or more protection devices of an power distribution network from fault events, which comprises a digital signal processor for executing a set of processing activities for regulating the operating state of said protection devices. The digital signal processor comprises a first computerized means for calculating the run-time computational load related to said digital signal processor and a second computerized means for reducing said run-time computational load, if said run-time computational load exceeds a predefined threshold.

Abstract: A winding for a transformer or coil includes a ribbon electrical conductor and at least one ribbon insulation material layer fitted thereto or applied as ribbon material thereto. The conductor and the insulating material layer are wound to form turns around a winding core along a winding axis. The individual turns of the winding have a predetermined winding angle with respect to the winding axis. A number of turns are located axially alongside one another form one layer, and at least two radially adjacent layers of turns are provided. A first layer of turns is radially adjacent to a second layer produced by changing the winding direction by folding the electrical conductor and the insulating material layer. The total angle, which is produced by the folding, between the longitudinal direction of the ribbon insulating material in the first layer and the corresponding direction of the second layer corresponds to twice the winding angle.

Abstract: A method for controlling the closing operation of a switching device, which is disposed on an electrical network connected to an inductive component. The method requires first data related to the electrical characteristics of the inductive component and the electrical network. Based on the first data, on a predefined first storage device containing opening and closing operation sequences, a first predefined opening operation sequence is selected. Then, based on the first predefined opening operation sequence, on the first storage device, a first predefined closing operation sequence is selected.

Abstract: A sound-insulating device for a stationary induction machine with an active part, an insulating fluid surrounding the active part, and a tank enclosing the insulating fluid. The sound-absorbing device includes a gas-filled cavity and a resilient member surrounding the gas-filled cavity, thus obtaining a sound-insulating device that is extremely compressible. In the induction machine, the device is arranged between the active part and the tank of the induction machine and is spaced from the inside of the tank. The sound-insulating device preferably has an extent in one plane, whereby the device has a membrane portion facing the active part and a membrane portion facing the tank. Preferably, at least one of the membrane portions has at least one corrugated region, and a spacing membrane is arranged in the cavity making contact with the membrane portion at at least two points.

Abstract: An electrical transformer including a tank containing transformer fluid, a transformer core and winding subassembly disposed in the transformer fluid within and spaced apart from the tank. An active device, disposed in the transformer fluid within the tank, various the volume of the transformer fluid in order to reduce pressure waves generated by the vibration of the core and winding subassembly during electromagnetic operation. The active device includes at least a cell having a main body and a corrugated membrane connected to the main body in order to realize a sealed container able to maintain a low pressure atmosphere inside, and an actuator placed inside the sealed container and solidly connected to the corrugated membrane.

Abstract: A pole of a high- and/or medium-voltage circuit breaker, including an insulating housing, at least one, interruption chamber which is positioned inside the insulating housing and contains at least a moving contact and at least a fixed contact. A device for measuring the electric current flowing through the pole, and a dielectric gas, the particularity of which is the fact that said device for measuring the electric current flowing through the pole includes an optical current sensor arranged within a volume of the pole that is occupied by the dielectric gas.

Abstract: An electric switching device for fast closing of a high current in a power network comprising a first electrode (1), a second electrode (2), a movable contact element (3) closing said first and second electrodes, and an operating device. The operating device comprises a helically wound first coil (6) secured to the first electrode. The movable contact element comprises a flange (4) making contact with the coil. A current pulse flowing through the coil forms a repulsive force between the coil and the flange, said repulsive force throwing the movable contact element to the second electrode and completing the closing operation.

Abstract: A series-compensating power flow transformer implements power flow control in a transmission line of an n-phase power transmission system, where each phase of the power transmission system has a transmission voltage. The transformer has n primary windings, where each primary winding is on a core and receives the transmission voltage of a respective one of the phases of the power transmission system. The transformer also has n secondary windings on the core of each primary winding for a total of n2 secondary windings. Each secondary winding has a voltage induced thereon by the corresponding primary winding, and one secondary winding from each core is assigned to each phase. For each phase, the secondary windings assigned to the phase are coupled in series for summing the induced voltages formed thereon, where the summed voltage is a compensating voltage for the phase.

Abstract: A power flow transformer implements power flow control in a transmission line of an n-phase power transmission system, where each phase of the power transmission system has a transmission voltage. The transformer has n secondary windings, where each secondary winding is on a core. The transformer also has n primary windings on the core of each secondary winding for a total of n2 primary windings, where one primary winding from each core is assigned to each phase. For each phase, the primary windings assigned to the phase are coupled in series, and the in-series primary windings receive the transmission voltage of the respective phase of the power transmission system. For each core, each primary winding thereon induces a voltage in the secondary thereon. The induced voltages are summed by the secondary to result in a summed induced voltage. Such summed induced voltage is a compensating voltage for a respective phase.

Abstract: Apparatus and methods for arc welding a stud to a workpiece without the use of a ferrule are disclosed. Apparatus according to the invention include a stud arc welding gun having a spacer at a distal end thereof, and a chuck adapted to receive a stud having a diameter of more than about ⅜ inch. A stud feeding device is coupled to the gun for automatically loading studs into the gun. The stud feeding device can include a bowl feeder and a stud feeding conduit via which studs are transferred from the bowl feeder to the stud gun. A gun positioning device, such as an arm of a robot, is coupled to the gun, and automatically positions the gun such that the spacer is against a receiving surface of the workpiece. A controller coupled to the stud gun initiates a stud arc welding process to arc weld the stud to the workpiece.

Abstract: A limited-angle power flow transformer implements power flow control in a transmission line of an n-phase power transmission system, where each phase of the power transmission system has a transmission voltage. The transformer has n primary windings, where each primary winding is on a core and receives the transmission voltage of a respective one of the phases of the power transmission system. The transformer also has m secondary windings on the core of each primary winding for a total of m*n secondary windings, where m is less than n. Each secondary winding has a voltage induced thereon by the corresponding primary winding. For each phase, m secondary windings are assigned to the phase. Each assigned secondary winding for the phase is from a different core. For all phases, the secondary windings are assigned from the cores in a balanced manner. For each phase, the secondary windings assigned to the phase are coupled in series for summing the induced voltages formed thereon.

Abstract: The present invention provides a system and method for attaching a device to an inside wall of an enclosure. The device is removably attached to a positioner. Where the device includes a metal substance, it may be attached to the positioner by a magnet affixed to the positioner, for example. A first motor-operated moving device moves the enclosure such that the device abuts an inside wall of the enclosure. A second motor-operated moving device, for example a robot, then attaches the device to the inside wall of the enclosure. Where the enclosure and the device are composed of metal, the two may be welded together. In this instance, the first motor-operated moving device may be a non-robotic, motor-operated moving device that provides a ground path for the weld.