Abstract: A transformer arrangement includes a first and a second arrangement side and a transformer with first windings coupled to the first arrangement side and with second windings having a first to a fourth tap. The transformer arrangement comprises a converter coupling the first, second and third tap to the second arrangement side, a first filter circuit coupling the first tap to the third tap and a second filter circuit coupling the third tap to the second tap.

Abstract: A transformer arrangement comprising a transformer having a primary side for receiving input voltage and current from a source and a secondary side for providing output voltage and current to a load. The transformer arrangement further comprises an AC-AC PE converter connected to a thyristor used for bypassing the AC-AC PE converter in case of a short-circuit fault in a terminal of the primary side and/or the secondary side. The transformer arrangement further comprises a thyristor-based AC-AC PE converter connected to a thyristor-tapped winding. The AC-AC PE converter is connected with the thyristor-tapped winding via the thyristor-based AC-AC PE converter. The thyristor-based AC-AC PE converter is connected to an impedance to protect the thyristor-tapped winding from short-circuit faults of the thyristor-based AC-AC PE converter.

Abstract: A method for controlling an output voltage of at least one transformer in a power grid comprises providing the one transformer(s) with a power electronics converter and an output voltage controller, determining a grid frequency, comparing the grid frequency with a reference value, producing an error signal, applying the error signal as feedback to the controller, and generating a control action to cause the controller to change the output voltage of the transformer comprising a power electronics converter. The power electronics converter is an AC-AC converter, and the method comprises connecting the AC-AC converter to either a primary side or a secondary side of the transformer. The AC-AC converter has a first AC side and a second AC side and the method comprises connecting two terminals on the first AC side to a winding of the transformer, and connecting the second AC side to an external circuit line.

Abstract: A transformer arrangement comprising a transformer having a primary side for receiving input voltage and current from a source and a secondary side for providing output voltage and current to a load. The transformer arrangement further comprises an AC-AC PE converter connected to a thyristor used for bypassing the AC-AC PE converter in case of a short-circuit fault in a terminal of the primary side and/or the secondary side. The transformer arrangement further comprises a thyristor-based AC-AC PE converter connected to a thyristor-tapped winding. The AC-AC PE converter is connected with the thyristor-tapped winding via the thyristor-based AC-AC PE converter. The thyristor-based AC-AC PE converter is connected to an impedance to protect the thyristor-tapped winding from short-circuit faults of the thyristor-based AC-AC PE converter.

Abstract: A method for controlling an output voltage of at least one transformer in a power grid. The comprises providing the least one transformers with a power electronics converter and an output voltage controller, determining a grid frequency, comparing the grid frequency with a reference value, producing an error signal, applying the error signal as feedback to the controller, and generating a control action to cause the controller to change the output voltage of the transformer comprising a power electronics converter. The power electronics converter is an AC-AC converter, and the method comprises connecting the AC-AC converter to either a primary side or a secondary side of the transformer. The AC-AC converter has a first AC side and a second AC side and the method comprises connecting two terminals on the first AC side in-parallel to a winding of the transformer, and connecting the second AC side to an external circuit line.

Abstract: A transformer arrangement is provided. The transformer arrangement includes a transformer with a primary and a secondary winding and a chain link of switching blocks connected in series between one of the windings and a load, where the switching blocks comprise a first set of voltage contribution blocks and a second set of circuit breaker blocks, where the first set of voltage contribution blocks is configured to adjust a voltage output by the transformer with an offset voltage and the second set of circuit breaker blocks is configured to interrupt a current running through the chain link.

Abstract: Provided is a transformer arrangement wherein active and/or reactive power can be injected in an alternating current link using a current regulator and a voltage regulator portion, wherein at least one winding with which the current regulator is connected in parallel is at least one tertiary winding, and wherein the current regulator includes a number of current regulator sections, each connected to a corresponding voltage regular section of a voltage regulator portion via a corresponding dc link.

Abstract: The invention relates to the method of exploration at well level (one-dimensional) of the content and quality of organic matter in source rocks in marine environments. The method for determining the content and maturation of organic carbon by (multi)one-dimensional simulation makes it possible to estimate the production, preservation and degradation of this carbon in a given well (or multiple wells) located in a sedimentary basin, in order to characterize the organic facies present in the marine environment.

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: Battery energy storage arranged to be connected to a direct current capacitor, which is connected in parallel to a power converter. The battery energy storage includes a battery module and a controllable voltage source adapted to inject a voltage opposite to a voltage ripple of the direct current capacitor. A power system including such battery energy storage and a direct current capacitor is also disclosed.

Abstract: Battery energy storage arranged to be connected to a direct current capacitor, which is connected in parallel to a power converter. The battery energy storage includes a battery module and a controllable voltage source adapted to inject a voltage opposite to a voltage ripple of the direct current capacitor. A power system including such battery energy storage and a direct current capacitor is also disclosed.