Siemens Aktiengesellschaft

Siemens Ag Osterreich

Siemens Energy Global Gmbh & Co. Kg

Siemens Transformers Austria Gmbh & Co. Kg

Peter Hamberger

Albert Leikermoser

Georg Pilz

Alfons-Karl Schrammel

Gerald Leber

Günther Weidenholzer

Helmut Pregartner

Gunther Weidenholzer

Harald Mayer

Markus Wiesinger

Patrik Ernst

Florian Bachinger

Anel Hrustic

Juergen Lottes

Helfried Passath

Clemens Keplinger

Markus Stockner

Jurgen Lottes

Jürgen Lottes

Martin Mairinger

A radiator for cooling a transformer, preferably a power transformer, or a choke, includes a plurality of plate-shaped radiator elements which are disposed parallel to one another and through which a coolant can flow in parallel. At least one elastically deformable element is provided at least between two adjacent radiator elements and is constructed in such a way that it counteracts an expansion of the radiator elements perpendicular to the surface of the radiator elements. Plastic deformation of the walls of the radiator elements can be prevented by the elastically deformable elements. A unit including a transformer or a choke and a method for producing a radiator are also provided.

Radiator for cooling a transformer or a choke, unit including a transformer or a choke and method for producing a radiator

Measuring arrangement for detecting a magnetic unidirectional flux in the core of a transformer, wherein a sensor, formed from a ferromagnetic sensor core which is surrounded by a sensor coil, is arranged in a section of a core limb in a cooking channel, where the section is predefined by the width of the winding, or is arranged in an annular space, formed from an outer peripheral surface of the core limb and an inner peripheral surface of an associated transformer winding, such that a magnetic partial flux is diverted by the core limb and guided over at least one non-ferromagnetic gap.

Measuring arrangement for detecting a magnetic unidirectional flux in the core of a transformer

A circuit arrangement for reducing a magnetic unidirectional flux component in a core of a transformer includes a measuring device that provides a sensor signal corresponding to the magnetic unidirectional flux component, a compensation coil magnetically coupled to the core of the transformer, and a semiconductor switching device which is electrically arranged in a current path in series with the compensation coil to feed a current into the compensation coil, such that current is directed opposite the unidirectional flux component, where the semiconductor switching device is controlled via a control signal provided by a controller, and includes an inductive voltage divider having a first impedance component arranged in a current circuit in series with the compensation coil and the semiconductor switching device and a second impedance component arranged in parallel with the semiconductor switching device, where the first impedance component is connected in parallel with a parallel resonant circuit.

Circuit arrangement for reducing a magnetic unidirectional flux component in the core of a transformer

An apparatus for reducing a magnetic unidirectional flux component in the core of a transformer with at least three legs, in particular a three-phase transformer having at least one compensation winding per transformer leg, wherein the compensation windings are magnetically coupled to the core of the transformer, where two compensation windings are provided per leg, the first compensation windings of a leg are each electrically connected together in a first delta connection, in each case the second compensation windings of a leg are each electrically connected together in a second delta connection, the compensation windings of at least one leg have different numbers of windings, and where at least one switching unit is arranged in series with the compensation windings for phase angle control.

Apparatus for reducing a magnetic unidirectional flux component in the core of a transformer

A device for reducing a magnetic unidirectional flux component in the core of a three-phase transformer includes at least one compensation winding, which is magnetically coupled to the core of the three-phase transformer, a switch arranged electrically in a current path in series with the at least one compensation winding to feed current into the winding, where the effect of the current is directed opposite to the unidirectional flux component, and an apparatus for limiting current arranged electrically in a current path in series with the at least one compensation winding, and where two compensation windings are provided on different legs of the core of the three-phase transformer such that a greater reduction of the magnetic unidirectional flux component is achieved.

Device and method for reducing a magnetic unidirectional flux component in the core of a three-phase transformer

An arrangement for reducing a magnetic unidirectional flux component in the core of a transformer includes a measurement apparatus which provides a measurement signal corresponding to the magnetic unidirectional flux component, a compensation winding magnetically coupled to the core of the transformer, wherein magnetic flux flowing in the core induces a voltage in the compensation winding, a switch device arranged electrically in series together with the compensation winding in a current path, a control device which controls the switch device via a control parameter, where the switch unit comprises a magnetic core and a winding arrangement which is magnetically coupled to the magnetic core, and the control parameter is supplied to the winding arrangement such that the magnetic saturation state of the core is variable, whereby the conductive state of the switch unit can be produced.

Arrangement and method for reducing a magnetic unidirectional flux component in the core of a transformer

An apparatus for reducing a magnetic unidirectional flux component in the core of a transformer, i.e., a three-phase transformer, includes a plurality of compensation windings that are magnetically coupled to the core of the transformer, wherein a controllable current source for feeding current into the compensation windings is arranged electrically in series with the compensation windings, specifically with the neutral point thereof, which is forming by the inputs of the compensation windings, and a neutral earthing transformer is electrically connected to the outputs of the compensation windings, where the current source electrically interconnects the neutral point of the compensation windings and the neutral point of the neutral earthing transformer.

A device for reducing a magnetic unidirectional flux component in the core of a transformer includes at least one compensation winding, which is magnetically coupled to the core of the transformer, at least one switching unit in series with the compensation winding to feed a current into the compensation winding, and at least one current-limiting reactor in series with the compensation winding, wherein two switching units are connected in parallel with each other per current-limiting reactor and the current-limiting reactor comprises two windings, which can be connected either in series or in parallel with each other, in order to reduce the number of current-limiting reactors in comparison with conventional cascaded circuits.

Device and method for reducing a magnetic unidirectional flux component of a transformer core

A circuit arrangement for compensation of a DC component in a transformer, wherein the transformer includes a winding arrangement connected via connecting lines to a power system for transporting electrical energy, and includes a neutral point connected to earth, where the circuit arrangement includes a transductor circuit arranged in a current path that connects a connection point situated on a node-free portion of the connection line to earth, a control and regulation device that controls the transductor circuit via a control signal and to which is fed, on the input side, a signal provided by a detection device with respect to a size and direction of the DC component to be compensated.

Circuit arrangement for compensation of a DC component in a transformer

A system for compensating one or more DC components in an electrical system includes one or more sensors for sensing the one or more DC components. The system also includes one or more DC component controllers for generating one or more reference signals from one or more signals received from the one or more sensors. In addition to this, the system also has one or more controllers for generating one or more firing pulses from the one or more reference signals received from the one or more DC component controllers and one or more valve configurations for charging one or more controllable branches to counterbalance the one or more DC components of the electrical system. A method for compensating one or more DC components in an electrical system is also provided.

DC compensation for high DC current in transformer

A circuit arrangement for reducing unidirectional flux component in a transformer core includes a compensation winding magnetically coupled to the transformer core, a transductor series connected with the compensation winding in a compensation current path, wherein the compensation current path has two parallel branches each containing a power winding of the transductor and an uncontrolled valve connected in series, where flow directions of the valves run counter to one another, and where each power winding is magnetically coupled to a control winding via a saturable transductor core, and includes a controller to which a detector supplies magnitude and direction information of the unidirectional flux component, and which generates a control variable supplied to each control winding such that the saturation state of the transductor core is variable such that a compensation current is formed in the compensation current path that counteracts the unidirectional flux component in the transformer core.

Circuit arrangement for reducing a unidirectional flux component in the soft-magnetic core of a transformer

An arrangement for reducing a DC field component in the core of a transformer includes a compensation winding magnetically coupled to the core of the transformer, and a DC generator arranged in series with the compensation winding and with a reactance dipole. The reactance dipole is formed from a parallel circuit of an inductance and a capacitor to feed into the compensation winding a compensating current opposite in sense to the DC field component in the core. The inductance is formed from magnetically coupled first and second windings having Nand Nturns respectively, such that N/N&#x3c;1. The first winding is connected on one end to the DC generator and on the other end to the compensation winding. The second winding is connected in parallel with the capacitor. The magnetic coupling of the first and second windings is established via a soft magnetic core having an air gap.

Arrangement and method for the compensation of a magnetic unidirectional flux in a transformer core

A device for reducing a magnetic unidirectional flux fraction in the core of a transformer is provided. The device has a measuring device that provides a sensor signal corresponding to the magnetic unidirectional flux fraction, a compensation winding that is magnetically coupled to the core of the transformer, a switching unit arranged electrically in a current path in series with the compensation winding in order to feed a current into the compensation winding. The action of the current is directed opposite to the unidirectional flux fraction. The switching unit can be controlled by a regulating variable provided by a control device and can be switched into a conductive state during a predefined time interval and in accordance with the regulating variable, the switch-on time being mains-synchronous. A device for limiting the current in the current path is provided and the sensor signal is fed to the control device.

Device and method for reducing a magnetic unidirectional flux fraction in the core of a transformer

A technique is provided for detecting a magnetic characteristic variable in particular the magnetic field strength in a section of a core permeated by a magnetic flux. A portion of the magnetic flux is branched off from the core and passed via a magnetic shunt branch, in which at least one non-ferromagnetic gap is formed. A shunt part is disposed in the shunt branch, wherein the magnetic material of the shunt part is not saturated. At least one section of the shunt part is wound with at least one sensor coil in which the branched-off portion of the magnetic flux generates a sensor signal by induction. The magnetic characteristic variable is determined from the branched-off portion of the magnetic flux or a variable derived therefrom using a sensor and evaluation device to which the sensor signal is fed.

Method and apparatus for detecting a magnetic characteristic variable in a core

An electrical transformer with unidirectional flux compensation is provided. The transformer includes a soft magnetic core on which a primary winding arrangement, a secondary winding arrangement, and a compensation winding arrangement are arranged. The compensation winding arrangement is connected to a current control device which feeds a compensation current into the compensation winding arrangement using a control signal. A magnetic field measuring device measures the magnetic field in the core of the transformer or the stray magnetic field that closes outside the core via an air path and provides the control signal.

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Kirchschlag bei Linz, Austria

Peter Hamberger