Abstract: It is presented a DC/DC converter for converting power between a first DC connection comprising a first positive terminal and a first negative terminal, and a second DC connection comprising a second positive terminal and a second negative terminal. The DC/DC converter comprises: a first multilevel converter and a second multilevel converter connected serially between the first positive terminal and the first negative terminal, wherein the second positive terminal is connected to a point between the first multilevel converter and the second multilevel converter; and a first filter connected between an AC terminal of the first multilevel converter and an AC terminal of the second multilevel converter, wherein the first filter comprises a capacitor and an inductor.

Abstract: A switch assembly including a vacuum switch mounted to an at least partly electrically conductive housing, and a holder for a vacuum bottle. The housing includes at least one gas entry opening at a lower end of the housing and at least one gas exit opening at an upper end of the housing, and a first free heat convection path between the openings to provide cooling. A second free heat convection path may be provided in a free space between the holder and vacuum bottle. A switching device for connecting the vacuum switch to a second electric conductor. An electric power distribution switchgear, encapsulating at least one three-phase module including a switching device.

Abstract: A method and apparatus are provided for differential protection of a three phase electric connection of an electric system. The apparatus includes means for determining a value of an operate quantity, which operate quantity is based on a difference between current quantities at a first point and a second point of the electric connection, and means for detecting a fault in the electric connection between the first point and the second point if the value of the operate quantity exceeds a value of a predetermined threshold quantity. The operate quantity is based on a difference of residual currents at the first point and the second point, or a quantity indicative thereof, and a coefficient indicative of an angle between a residual voltage of the electric connection and the difference of residual currents at the first point and the second point.

Abstract: A containment system for internal arc generated gasses includes a compartment having an aperture through a wall thereof. A bus compartment includes an opening through a wall thereof. Arc chamber is in communication with the aperture and the opening. A vent flap member closes the opening and is moveable to an open position to permit gasses to flow through the opening into the arc chamber. Flap structure is associated with the aperture and includes a plurality of interconnected flaps for moving generally simultaneously from an open position, permitting gasses to flow through the aperture into the arc chamber, to a closed position, closing the aperture to prevent gasses from flowing through the aperture. The flap structure includes actuating structure coupled with the interconnected flaps. The vent flap member, when moved to the open position thereof, engages the actuating structure to move the interconnected flaps to the closed position thereof.

Abstract: A connecting apparatus for mounting on a vehicle or charging station, providing an electrical connection between the station and vehicle for charging an storage device of the vehicle, comprising: a contacting head for transferring electrical energy; at least one alignment device for coupling the contacting head to a receiver; a detector configured to determine a position of the receiver; and a control unit for aligning the contacting head and receiver; and wherein the alignment device includes a horizontal positioner; a pivoter for pivoting a contacting post carrying the contacting head from a parking position to a substantially vertical position; and a vertical positioner for telescoping the contacting post to adapt its length. The horizontal and vertical positioners, and pivoter performing an alignment movement independent from the others.

Abstract: A method for transmitting a file from a file source (101) to a plurality of electronic devices (110j) is described herein. To each electronic device are associated an encryption key and a unique identifier code. According to the method described herein, to the plurality of electronic devices are transmitted: a file encrypted by means of a session key, and a plurality of encrypted session keys, each paired with a respective electronic device, with whose encryption key the respective encrypted session key was obtained; Moreover, each electronic device decrypts its own encrypted session key using the respective encryption key to obtain the decrypted session key, and decrypts the encrypted file by means of the decrypted session key.

Abstract: A dry-type electrical transformer includes a coil assembly having at least one winding wound into a plurality of concentric turns, at least one cooling sector defined between adjacent concentric turns, spacers positioned inside the cooling sector and spaced from each other to allow a plurality of air ducts each defined between two adjacent spacers, and at least one electrical shield positioned in the cooling sector and arranged to electrically shield the air ducts. At least one electrical shield is positioned in the cooling sector and arranged to electrically shield the air ducts. The electrical shield include a first end edge connected to the turn at the inner side of the cooling sector, a second end edge which is free and electrically insulated from the surrounding parts, and a central portion extending between the first and second end edges and is positioned at the outer side of the spacers.

Abstract: A method and system for measuring an electrical quantity in an electrical network. The system is configured to obtain samples of the electrical quantity through measurements at different feeders or locations in the electrical network. The measurements are taken in turns and at different time instants, such that a value sequence is created on the basis of the measured samples.

Abstract: A vacuum interrupter is disclosed with transition areas between metal housing parts and ceramic housing parts covered by insulating material. To enhance dielectric performance and field grading behavior, the insulating material can extend as a tube or a multilayer tube design over at least nearly a complete length of the vacuum interrupter or vacuum device arrangement. The insulating material can be filled or at least covered at an inner surface which comes into close contact with the vacuum interrupter or vacuum device surface, with metal and/or conductive metal oxides.

Abstract: An electrical switchgear system includes a first compartment supplied with cooling air and in fluid communication with an exhaust plenum. A second compartment is in fluid communication with the exhaust plenum. A deflector is operative to deflect an amount of the cooling air from the first compartment and direct it into the second compartment. An electrical switchgear system having switchgear in an enclosure includes a first compartment disposed inside the enclosure and supplied with cooling air. A second compartment is disposed inside the enclosure. A deflector is operative to capture an amount of the cooling air from the first compartment and direct it into the second compartment.

Abstract: A multiphase medium voltage vacuum contactor is disclosed which can include a mounting frame on which there are positioned: for each phase, a current interrupter having a vacuum bulb which contains a fixed contact and a corresponding movable contact; and an actuator for moving the movable contacts between a closed position where they are coupled each to a corresponding fixed contact and an open position where they are each electrically separated from the corresponding fixed contact, and an electronic unit driving the actuator. An exemplary voltage transformer for feeding the electronic unit can be mounted on the frame. One or more sacrificial fault-protection devices and/or current sensors can be operatively associated to the voltage transformer and embedded into an electrically insulating coating encasing the transformer.

Abstract: A method and arrangement for determining the flow rate (Q) produced by a pump, when the pump is controlled with a frequency converter, which produces estimates for rotational speed and torque of the pump, and the characteristic curves of the pump are known. The method includes determining the shape of a QH curve of the pump, dividing the QH curve into two or more regions depending on the shape of the QH curve, determining on which region of the QH curve the pump is operating, and determining the flow rate (Q) of the pump using the determined operating region of the characteristic curve.

Abstract: A method and arrangement for operating a pump system are disclosed, the pump system including a pump arranged to be rotated with an AC motor, an inverter, the output of which is electrically connected to the AC motor, and a photovoltaic panel system electrically connected to feed DC power to the inverter. The method can include setting a voltage limit, and determining continuously voltage obtained from the photovoltaic panel system. When the determined voltage of the photovoltaic panel system is below the set voltage limit, frequency of the inverter can be controlled such that the ratio between output voltage of the inverter and the output frequency is substantially constant. When the determined voltage of the photovoltaic panel system exceeds the voltage limit, the inverter frequency can be controlled for keeping voltage of the photovoltaic panel system substantially at the voltage limit.

Abstract: A pressure transmitter and method for measuring pressure exerted by a fluid on the diaphragm of the pressure transmitter. A pressure sensor assembly can include a diaphragm displaceable under pressure exerted by the fluid, and first and second electronic circuits generating first and second oscillating signals, respectively, whose frequencies depend on the displacement of the diaphragm. First and second numerical values which are representative of the oscillating frequencies of the first and second oscillating signals, respectively. A signal indicates pressure exerted by the fluid on the diaphragm based on the first and second calculated numerical values.

Abstract: A circuit breaker including an ejection device with a compartment, in which an arc-extinction medium for improving circuit breaker operation is contained, and having an ejection orifice through which the arc-extinction medium is to be ejected, wherein the ejection orifice opens out into an injection zone of the circuit breaker in which the pressure is lower than in an arcing zone when an arc is present, and wherein the arc-extinction medium and/or exhaust-cooling medium is at least partially present in liquid form, when it is contained in the ejection device.

Abstract: A method of manufacturing a polymer-insulated conductor. The method includes the steps of a) providing a conductor having a first cross-sectional shape, b) passing the conductor through a conductor-shaping die to shape the conductor such that the conductor obtains a second cross-sectional shape, wherein frictional heat is developed in the conductor, thereby setting the conductor in a heated state, c) applying molten polymer to the conductor when the conductor is in the heated state to obtain a polymer-coated conductor, and d) shaping the polymer-coated conductor by means of a polymer-shaping die to thereby obtain the polymer-insulated conductor.

Abstract: A unique electrical switchgear system may include a circuit breaker compartment having a compartment wall. The electrical switchgear system may also include a tapered floor pan mounted on the compartment wall. The floor pan may have two side walls disposed oblique to each other; a back wall; and a top wall coupled to the side walls and defining a discharge opening adjacent to the back wall. The two side walls, the top wall and the compartment wall may form a tunnel for channeling cooling air in a first direction. The back wall may be operative to redirect the cooling air in a second direction different from the first direction for discharging the cooling air from the discharge opening.

Abstract: An on-load tap changer is provided and includes a plurality of modules disposed in an interior space of a tank and arranged in a side-by-side manner. Each module has a bypass switch assembly and a vacuum interrupter assembly mounted to a first side of a board. The bypass switch assembly is actuated by rotation of a bypass cam and the vacuum interrupter assembly is actuated by rotation of an interrupter cam. A transmission system rotates the bypass cam and the interrupter cam. The transmission system is mounted on a second side of the board.