A transformer arrangement includes a transformer having a winding and a surge arrester arrangement connected thereto. The SAA includes a surge arrester (SA) connected across at least a section of the winding and a switch operable between a closed and open state. In the closed state, SA is electrically connected across at least the section, and in the open state, the SA electrically disconnected from at least the section. The SAA includes at least one further SA .sub.arranged to be connected across at least one further section and at least one further switch, operable between a closed and open state, wherein in the closed state the further SA is electrically connected across the at least one further section, and in the open state, the at least one further SA is electrically disconnected from the further section. A method for electrically connecting/disconnecting the transformer to/from the SAA—is also described.

An arrangement for an overvoltage protection of a subsea electrical apparatus and a method for operating it. The arrangement includes a tank submersible below a water surface level, an electrical apparatus accommodated in the tank, and a surge arrester arrangement accommodated in the tank and coupled to a power supply of the electrical apparatus in the tank for providing the overvoltage protection of the electrical apparatus. The arrangement further includes a controllable grounding switch for connecting the surge arrester arrangement to a ground point in response to a control of the grounding switch to a closed state and for disconnecting the surge arrester arrangement from the ground point in response to a control of the grounding switch to an open state.

An electronics assembly includes a plurality of planar conductive metal sheets including a first conductive metal sheet, a second conductive metal sheet attached and electrically coupled to the first metal sheet, and a third conductive metal sheet attached and electrically coupled to the second metal sheet. The second metal sheet is located between the first and third conductive metal sheets. Air gaps are defined in the plurality of planar conductive metal sheets to form metal traces that define electrically isolated conductive paths from an outer surface of the first conductive metal sheet to an outer surface of the third conductive metal sheet in a multilevel conductive wiring network. The multilevel conductive wiring network can be attached and electrically coupled to a microchip and to one or more capacitors to form a power converter.

An electronic apparatus is provided. The electronic apparatus includes: a main circuit; and a power supply circuit configured to receive external power from an external power supply and supply operating power to the main circuit. The power supply circuit includes: a converter; and a lightning protection circuit that includes: a varistor configured to have a first rated voltage corresponding to a breakdown voltage of a device of the converter; and a surge arrester connected in series to the varistor and configured to have a second rated voltage, and based on the external power being higher than the first rated voltage of the varistor, the varistor is clamped so that a voltage applied to the converter does not exceed the first rated voltage, and based on a voltage applied to the surge arrester being equal to or higher than the second rated voltage, the surge arrester is short-circuited.

Transformer assembly including a first transformer stage having a plurality of first-stage transformer cells; and a second transformer stage. An input of the second transformer stage is connected to an output of the first transformer stage. A lightning impulse breakdown voltage of a transformer cell of the second stage is at least double of a lightning impulse breakdown voltage of transformer cells of the first stage.

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.

A linear optimized isolation transformer may include a magnetic core having a primary side and a secondary side; a primary side winding on the primary side; a primary side terminal electrically coupled to the primary side winding; a secondary side winding on a the secondary side; a secondary side terminal electrically coupled to the secondary side winding; an isolation dielectric placed between the primary side winding and the secondary side winding and having a shape that fills all of the space between the primary side and the secondary side that is not occupied by the core, the isolation dielectric including a permanent high-Q material selected to maintain a high value isolation independent of pressure differences resulting from operation at different altitudes; and wherein the primary side terminal and the secondary side terminal are positioned on opposing ends of a long axis of the magnetic core.

An arrangement for an overvoltage protection of a subsea electrical apparatus and a method for operating it. The arrangement includes a tank submersible below a water surface level, an electrical apparatus accommodated in the tank, and a surge arrester arrangement accommodated in the tank and coupled to a power supply of the electrical apparatus in the tank for providing the overvoltage protection of the electrical apparatus. The arrangement further includes a controllable grounding switch for connecting the surge arrester arrangement to a ground point in response to a control of the grounding switch to a closed state and for disconnecting the surge arrester arrangement from the ground point in response to a control of the grounding switch to an open state.

Arrangement of interleaved secondary windings for power transformers that reduces the thickness of secondary windings and allows to build transformers with an odd number of layers.

An electronic device has a primary loop circuit that includes a main circuit causing a current to flow in a loop shape; and a secondary loop circuit that is disposed to face the primary loop circuit at a predetermined distance, and causes an induced current generated by a magnetic field generated in the primary loop circuit to flow in a loop shape.