Abstract: A dual active bridge DC/DC converter in accordance with the invention comprises a first DC link, preferably comprising a first DC link capacitor; a converter bridge connected to the first DC link; a transformer, preferably a medium frequency transformer, having a primary side and a secondary side; the primary side of the transformer comprising a plurality of M>1 primary windings, each of the plurality of primary windings having a first and a second terminal; wherein the dual active bridge DC/DC converter further comprises a first plurality of M energy transfer inductors; and wherein for each of the M primary windings, a different one from the first plurality of energy transfer inductors is connected between said primary winding bridge and the converter bridge.

Abstract: A transformer coil comprises low and high voltage windings wound on a supporting construction and immersed in a main insulation material. The transformer coil has also a first barrier arranged proximate the low voltage winding and a second barrier arranged proximate the high voltage winding. Each of the first and second barriers is gas-tight and semiconductive so that gas bubbles potentially released during immersion in the main insulation material are unable to migrate to a high electric field region during the casting process or during apparatus operation.

Abstract: A multi-pulse line-interphase transformer converter includes an electric part that includes magnetic components configured to be connected to a three-phase AC grid, and an electric part that includes a multi-phase voltage system configured to be connected to a common DC capacitor. The electric part splits each AC grid phase n times into two phases, resulting in a plurality of intermediate phases at an internal interface, each intermediate phase corresponding to a pulse of the multi-pulse line-interphase transformer converter. The intermediate phases are connected to the multi-phase voltage system. The multi-phase voltage system comprises bridges with actively controlled switches. The bridges are connected in parallel to the common DC capacitor.

Abstract: An electrical device includes a magnetic core, a bobbin extending about and partially covering the magnetic core, wherein the bobbin is made of a thermally conductive dielectric material, wherein the bobbin further comprises an outer body connectable to an inner body, wherein the inner body comprises at least a first contact element being formed as a rib that is configured to directly contact a surface of the magnetic core.

Abstract: A multi-phase inductor includes a core made of a magnetic material; at least two phase windings surrounding the core for inducing a magnetic field in the core, such that a common mode inductance (LCM) is provided for the at least two phase windings; and an adjustment member made of a magnetic material, which adjustment member has at least two legs, which are interconnected with each other at an inner end and which are touching the core at an outer end to provide a differential mode inductance (LDM) for the at least two phase windings; wherein the outer end of each leg of the adjustment member overlays an axial side of the core and/or each leg of the adjustment member has a varying thickness between the inner end and the outer end to adjust the differential mode inductance (LDM).

Abstract: A LIT-based bi-directional medium voltage converter topology includes active medium voltage switches that comprise low voltage switches connected in series and/or switch-cells in a cascode-configuration.

Abstract: A bi-directional medium voltage converter topology includes an n-pulse line-interphase-transformer, LIT; a plurality of bi-directional medium voltage, MV converters connected to the LIT on an AC side thereof and connected in parallel on a DC side thereof; a bi-directional multi-stage DC/DC converter connected to the plurality of bi-directional MV converters; and a bi-directional low voltage, LV, DC/DC converter; wherein the multi-stage DC/DC converter and the LV DC/DC converter are connected to each other galvanically insulated.

Abstract: A charging system for electric vehicles includes a line interphase transformer, LIT-based rectifier configured for connecting an input of the LIT-based rectifier to an AC medium-voltage power signal and for outputting a medium-voltage DC-signal; a modular DC/DC converter with large step-down gain is configured for transforming the medium-voltage DC-signal into a medium-voltage HF-AC-signal; and a medium-frequency transformer, MFT, is configured for transforming the medium-voltage HF-AC-signal into a low-voltage HF-AC-signal for the at least one charging box.

Abstract: A multi-pulse line-interphase transformer converter includes an electric part that includes magnetic components configured to be connected to a three-phase AC grid, and an electric part that includes a multi-phase voltage system configured to be connected to a common DC capacitor. The electric part splits each AC grid phase n times into two phases, resulting in a plurality of intermediate phases at an internal interface, each intermediate phase corresponding to a pulse of the multi-pulse line-interphase transformer converter. The intermediate phases are connected to the multi-phase voltage system. The multi-phase voltage system comprises bridges with actively controlled switches. The bridges are connected in parallel to the common DC capacitor.

Abstract: A power supply system includes a power feeding system for transforming an AC medium-voltage power signal from a medium-voltage grid into a low-voltage power signal for feeding an electricity consumer site. The power supply system further includes a low-voltage multiphase converter for transforming a low-voltage signal into a low-voltage multiphase signal. The multiphase converter is arranged antiparallel to the power feeding system, and an LV/MV multiphase transformer for transforming the low-voltage multiphase signal into an output-signal that is conformant to the AC medium-voltage power signal.

Abstract: A power electronic converter includes a plurality of converter cells, each comprising an inductive power transfer stage having a coupled inductor coupling first and second sides of the converter cell, wherein the inductor comprises a first winding around a first magnetic core and a second winding around a second magnetic core; wherein the first winding and the first magnetic core are separated from the second winding and the second magnetic core by a flat electric insulation layer that provides electric insulation between the first and second sides of the converter cell; wherein at least two of the coupled inductors are arranged so that their insulation layers form a single contiguous insulation layer.

Abstract: A medium frequency transformer for a DC/DC converter includes: a core having an air gap and a coil surrounding a core section and having a plurality of windings; a medium voltage electric insulation, surrounding the coil each winding including a first and second termination, and a conductor wound around a portion of the core in at least one turn between the first and second termination; a plurality of terminals provided outside the insulation, each connected to a different first termination by one of a plurality of connectors, a channel extending from an outside of the insulation into and at least partially through said electric insulation, wherein the connectors extend through the channel and are insulated against one another by means of a low voltage insulation within the channel. The second terminations are connected to one another within or inside the insulation and connected to a second terminal outside of the insulation by a second connector.

Abstract: A resonant DC/DC converter which has a first DC link, preferably including a first DC link capacitor; a DC/AC converter which has a first plurality of N>1 converter bridges connected in parallel to the first DC link; each converter bridge comprising a plurality of switches each of which may be switched between a conducting state and a non-conducting state. The resonant DC/DC converter also includes an AC intermediate circuit having an input connected to an output of the DC/AC converter and comprising: a transformer, preferably a medium frequency transformer, having a primary side and a secondary side; the primary side comprising at least one primary winding; a first plurality of N capacitors, wherein for each converter bridge, a different one from the first plurality of capacitors is connected between said converter bridge and the at least one primary winding.

Abstract: A method for producing a coil for a transformer, in particular for a medium frequency transformer for a resonant DC/DC converter or a dual active bridge DC/DC converter, is disclosed which: providing a plurality of M>1 conductive foil strips, each having a first ending and a second ending; stacking the plurality of conductive foil strips to obtain a foil strip stack having a first ending and a second ending, wherein an electrically insulating layer is provided between any two adjacent foil strips; electrically interconnecting the first endings of all conductive foil strips to a first terminal; for each of the conductive foil strips providing a connector at the second ending of the foil strip; and coiling up the foil strip stack from the first end.

Abstract: A DC/DC converter which includes a first DC link, preferably a first DC link capacitor; a first plurality of N>1 converter bridges connected in parallel to the first DC link; and a transformer, preferably a medium frequency transformer. The transformer includes a primary side and a secondary side, wherein the primary side includes at least one primary winding. The converter further comprises a first plurality of N impedance elements, wherein for each converter bridge, a different one from the first plurality of impedance elements is connected between said converter bridge and the at least one primary winding.

Abstract: 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.

Abstract: A dual active bridge DC/DC converter in accordance with the invention comprises a first DC link, preferably comprising a first DC link capacitor; a converter bridge connected to the first DC link; a transformer, preferably a medium frequency transformer, having a primary side and a secondary side; the primary side of the transformer comprising a plurality of M>1 primary windings, each of the plurality of primary windings having a first and a second terminal; wherein the dual active bridge DC/DC converter further comprises a first plurality of M energy transfer inductors; and wherein for each of the M primary windings, a different one from the first plurality of energy transfer inductors is connected between said primary winding bridge and the converter bridge.

Abstract: A transformer includes a first winding arranged around an axis, and a second winding arranged around the axis. The second winding includes a litz wire having an end portion located at an axial end position of the second winding and a middle portion located at an axial middle position of the second winding. The litz wire has a first cross section at the end portion and a second cross section at the middle portion, the cross sections each including in a quadrant between the axial outward direction and the direction pointing towards the first winding a curvature extending between the axial outward direction and the direction pointing towards the first winding. The curvature of the first cross section is smaller than the curvature of the second cross section thereby reducing the peak magnitude of the electrical field between the end portion of the second winding and the first winding.

Abstract: An electrical component includes a ferromagnetic core with a first and a second leg; a primary winding with a first primary winding portion arranged around the first leg of the ferromagnetic core and a second primary winding portion arranged around the second leg of the ferromagnetic core; wherein the first primary winding portion and the second primary winding portion each include parallel connectable conductors arranged around the ferromagnetic core in a cross section with the conductors being radially displaced with respect to each other at radial row positions, wherein the number of conductors of the first primary winding portion is equal the number of conductors of the second primary winding portion.

Abstract: A transformer includes a transformer core having a first core leg having a first longitudinal axis and second core leg having a second longitudinal axis; a first low voltage (LV) winding arranged around the first core leg, a first high voltage (HV) winding arranged around the first LV winding; a second low voltage (LV) winding arranged around the second core leg; and a second high voltage winding arranged around the second LV winding, wherein the first HV winding is provided with a first HV connector and a second HV connector each extending substantially perpendicular away from the first longitudinal axis, and wherein the second HV winding is provided with a third HV connector and a fourth HV connector each extending substantially perpendicular away from the second longitudinal axis.