Abstract: A method monitors capacitor bushings for an AC mains. The mains has first-third phases, associated with first-third mains lines, capacitor bushings, and mains voltages. Each capacitor bushing has a conductor, surrounded by foil, connecting its mains line. The method includes: at a first instant, for each phase: a first reference voltage phasor is determined; and a foil voltage present between the respective foil and ground potential is detected and a corresponding first foil voltage phasor is determined; at a second instant, for each of the phases: a second reference voltage phasor is determined; the foil voltage is detected and a second foil voltage phasor is determined; for each capacitor bushing: a loss factor change is calculated based on the respective reference voltages and foil phasors and those of the adjacent capacitive bushing; and a monitoring signal is generated based on a comparison of the loss factor and a tolerance value.

Abstract: A switch includes a diverter contact; a primary fixed contact; and a secondary fixed contact. The switch additionally includes a primary movable contact configured to be pivoted, relative to the diverter contact and the primary fixed contact, about a pivot axis between a first end position and a second end position. In the first end position, the primary movable contact bears by a first contact point against the diverter contact and by a second contact point against the primary fixed contact. The switch further includes a secondary movable contact configured to be pivoted, relative to the diverter contact and the secondary fixed contact, about the pivot axis between a first end position and a second end position. In the first end position the secondary movable contact bears by a third contact point against the diverter contact and by a fourth contact point against the secondary fixed contact.

Abstract: A method monitors capacitor bushings of a three-phase AC mains, which has first, second, and third mains lines respectively associated with first, second, and third: phases, capacitor bushings, and mains voltages. Each of the capacitor bushings has: a conductor connected with the associated mains line, and an electrically conductive foil enclosing the conductor. The method includes, for each of the phases: determining, at a predetermined initial instant for a characteristic variable, which is characteristic for the respective capacitor bushing, a corresponding characteristic value; determining, at a predetermined later instant after the initial instant for the characteristic variable, a corresponding normalised characteristic value in dependence on the respective characteristic value and/or on at least one of remaining characteristic values; and checking whether the normalised characteristic value has impermissibly changed.

Abstract: A power circuit has a power switching device (PSD) to, when in an ON state, conduct current from its first to second terminal; a diode anti-parallel to the PSD that, when in a non-blocking state, conducts current from its anode to its cathode; a drive input line coupled to a device control terminal of the PSD to control its switching; and sense circuitry, having a temperature sensitive current source (TSCS) coupled to a conduction terminal, providing a sense signal from the TSCS to the drive input line to indicate temperature. The TSCS is thermally coupled to the PSD, the temperature indicated is of the PSD, and the conduction terminal is the first or second terminal of the PSD; and/or the TSCS is thermally coupled to the diode, the temperature indicated by the sense signal is of the diode, and the conduction terminal is the anode or cathode of the diode.

Abstract: An on-load tap changer of a resistor type includes a selector base plate; a selector mounted on the selector base plate; a diverter switch base plate; a diverter switch mounted on the diverter switch base plate and having a transition resistor; and a common drive shaft which is configured to actuate the selector and the diverter switch.

Abstract: A method controls an UPS with a system having: first and second terminals, a switch having: first and second switch terminals respectively connected to the first and second terminals; first and second thyristors connected between the first and second switch terminals in anti-parallel; and an inverter connected to the second terminal and the energy store. Switch current and a first potential at the first terminal are detected. In a first fault, where the first potential drops past a first rule and the switch current rises above a second rule: a second potential at the second switch terminal is set using the inverter so the switch current becomes zero. Then the switch current is compared with a second threshold, and if it is exceeded, a first check result is positive, otherwise it's negative. When positive, the second potential is reversed.

Abstract: A method of controlling a regulating transformer with a settable translation ratio, switchable between a first and second AC-mains includes the following operations: detecting phasor data of phasors of the first and/or second AC-mains; determining an equivalent circuit diagram with equivalent circuit diagram parameters for the first AC-mains; determining a load model with load model parameters for the second AC-mains; determining the equivalent circuit diagram parameters and the load model parameters from the phasor data; and when switching over to a desired translation ratio is to take place: predicting a working point of the second AC-mains for the desired translation ratio; checking a stability criterion in the second AC-mains for the predicted working point; and switching over to the desired translation ratio is carried out upon the stability criterion being fulfilled, but otherwise not switching over to the desired translation ratio.

Abstract: A method of controlling at least one switching module having commutation cells which are associated with a regulating winding of a regulating transformer, the commutation cells including: a first and second switching element each having two thyristors in antiparallel connection.

Abstract: The invention relates to a switch assembly (1), in particular a preselector, for a variable transformer (4) having a first winding (2) and a second winding (3) with a first and a second tap (3.3, 3.4), said switch assembly comprising: a first connection terminal (2.1) that can be connected to the first winding (2); a second connection terminal (3.1) that can be connected to the first tap (3.3); a third connection terminal (3.2) that can be connected to the second tap (3.4); a first, second, third and fourth fixed contact (5.1, 5.2, 5.3, 5.4); a vacuum interrupter (6); a first moving contact (7) that can be contacted selectively with the first or second fixed contact (5.1, 5.2); a second moving contact (8) that can be contacted selectively with the third or fourth fixed contact (5.3, 5.4), wherein the second and the fourth fixed contact (5.2, 5.4) are connected to the second connection terminal (3.1), the first and the third fixed contact (5.1, 5.

Abstract: A selector for an on-load tap changer with a diverter switch includes: an insulating plate with a first side and a second side, the second side opposite the first side; a plurality of fixed contacts, which extend from the first side through the insulating plate to the second side; a first movable contact on the first side; a second movable contact on the second side; a first connection, which is connected with the first movable contact and which is connectable with a first branch of the diverter switch; and a second connection, which is connected with the second movable contact and which is connectable with a second branch of the diverter switch. Each of the first moveable contact and the second movable contact are selectably connectable with each of the fixed contacts.

Abstract: The present invention relates to an apparatus for calibrating a power measuring system for power transformers. The general inventive concept involves the two reference measuring systems that are known from the prior art for the calibration of a current transformer, a voltage transformer and an evaluation device being integrated in a shared apparatus, according to the invention, for calibrating a power measuring system for power transformers, which apparatus is furthermore arranged on a container such that the apparatus can be moved by means of a trailer that holds the container for the purpose of in-situ calibration of the power measuring system of power transformers.

Abstract: In a method for cleaning an on-load tap changer (19) in a regulating transformer (20), provision is made for the on-load tap changer (19) to comprise a moving contact (11) and a fixed contact (12); for a cleaning signal to be generated; for the moving contact (11) to be frictionally moved relative to the fixed contact (12) on the basis of the cleaning signal. An on-load tap changer (19) in a regulating transformer (20) comprises: —a moving contact (11) and a fixed contact (12); —a contact drive (17) which is coupled to the moving contact (11); —a control device (18) which is connected to the contact drive (17) and is designed in such a manner that the control device can generate a cleaning signal and can transmit said signal to the contact drive (17); wherein the contact drive (17) is designed in such a manner that the contact drive can frictionally move the moving contact (11) relative to the fixed contact (12) on the basis of the cleaning signal.

Abstract: A load stepping switch (1) for uninterrupted changeover between winding taps (n, n+1) on a control winding (20) comprises —a changeover switch (2) that comprises a first, second and third changeover contact (2.1, 2.2, 2.

Abstract: A switching arrangement (1), in particular a polarity switching means, for a control transformer (10) which comprises a first winding (2) for a phase of an AC power supply system, which phase is to be controlled, comprises —a first connection terminal (1.1) which can be connected to the winding (2); —a second connection terminal (1.2) which can be connected to a discharge line (3); —a vacuum interrupter (4); —an isolator (5); —a resistor (6) which is connected in series with the vacuum interrupter (4) and the isolator (5); wherein —the first connection terminal (1.1) is connected to the second connection terminal (1.2) by means of the series circuit.

Abstract: An electrical device (10, 13), in particular a power transformer (13), a shunt reactor, or an on-load tap changer (10), comprises a housing (101, 131) that is filled or fillable with insulation oil (11, 11?); and a sensor (12) that comprises a piezo element (16) in the housing (101, 131) on a level with a minimum fill level (19, 19?) of the insulation oil (11, 11?); and an evaluation device (18) that is connected to the piezo element (16); wherein the evaluation device (18) is formed such that it can induce an oscillation of the piezo element (16); and it can determine the fill level from a measurement of a characteristic of the oscillation, in particular the half-life period of the amplitude of the oscillation.

Abstract: A system for identifying or distinguishing materials, comprising at least one local apparatus and a central station. Each local apparatus comprises at least one measuring device for recording at least one actual signature for materials each and at least one local computer communicatively connected to the at least one measuring device, the at least one local computer having a local database for storing and/or processing the actual signature. The at least one central station comprises a server having a central database for storing and/or processing the actual signatures of the local apparatus. Furthermore, the system comprises a network, which communicatively connects the local computers of the local units via the server of the center. The invention further relates to a corresponding method for operating a system, to an analysis method for identifying or distinguishing the materials, and to a measuring device for recording material properties of the materials.

Abstract: The invention relates to a switching system for a tapped transformer with on-load tap changer wherein the tapped transformer comprises a main winding with a first main terminal; a coarse winding with a first coarse terminal and with a second coarse terminal; a control winding with a first control terminal; and an on-load tap changer that has a switch terminal and that interacts with the control winding; the switching system comprising a lead; a first switch subassembly comprising a first main fixed contact that can be connected to the first main terminal; a first coarse fixed contact that can be connected to the first coarse terminal; a first control fixed contact that can be connected to the first control terminal; a first switch fixed contact that can be connected to the first switch terminal; and a first movable bridge contact that is formed such that it electrically bridges or connects at least two fixed contacts of its switch subassembly in each stationary operating position of the switching system