A device for the production of a transformer is disclosed, comprised of at least two electrically conductive windings (A, B, C) adjacent to one another, and a ferromagnetic core (11; N2; N3) linked to the two electrically conductive windings, formed by wound strip-shaped ferromagnetic material. The device comprises guide members (9) configured and arranged so as to define a closed path linked to the two electrically conductive windings, along which one or more strip-shaped ferromagnetic materials can be wound from at least one coil (R; R1-R18).

A device for the production of a transformer is disclosed, comprised of at least two electrically conductive windings (A, B, C) adjacent to one another, and a ferromagnetic core (11; N2; N3) linked to the two electrically conductive windings, formed by wound strip-shaped ferromagnetic material. The device comprises guide members (9) configured and arranged so as to define a closed path linked to the two electrically conductive windings, along which one or more strip-shaped ferromagnetic materials can be wound from at least one coil (R; R1-R18).

An auto-transformer rectifier system comprising an 18-pulse (or multiple of 18-pulse) autotransformer rectifier unit ATRU having three, or a multiple of three, diode bridge rectifiers and a balancing resistor to balance the power flow through the diode bridge rectifiers, wherein the balancing resistor has a variable resistance, and further comprising a controller configured to identify imbalances between power flows of the respective diode bridge rectifiers and to adjust the resistance of the balancing resistor in response to the detected imbalance.

An auto-transformer rectifier system comprising an 18-pulse (or multiple of 18-pulse) autotransformer rectifier unit ATRU having three, or a multiple of three, diode bridge rectifiers and a balancing resistor to balance the power flow through the diode bridge rectifiers, wherein the balancing resistor has a variable resistance, and further comprising a controller configured to identify imbalances between power flows of the respective diode bridge rectifiers and to adjust the resistance of the balancing resistor in response to the detected imbalance.

A transformer for a multiphase power converter includes a magnetic structure, a first coil configured to electrically couple to an input circuit or an output circuit of a subconverter of the multiphase power converter, and a second coil configured to electrically couple to an input circuit or an output circuit of another subconverter of the multiphase power converter. The magnetic structure includes a top member, a bottom member, and legs extending between the top member and the bottom member in substantially the same direction. The legs include two outer members and two inner members. The first coil is wound about one of the two inner members of the magnetic structure, and the second coil is wound about the other one of the two inner members of the magnetic structure. Other example transformers, and multiphase power converters including transformers are also disclosed.

A coil device with a cooling structure includes: a coil unit that has a core structure having one or more leg parts and one or more coils wound around the one or more leg parts; and a flow-rectifying member having a flat plate portion covering a face of the one or more coils and flow-rectifying ribs inwardly protruding from an inner surface of the flat plate portion, the flow-rectifying ribs extending in a direction parallel to center axes of the one or more coils and being positioned to face side boundaries of the face of the one or more coils. The flat plate portion and the flow-rectifying ribs form a first air cooling channel at a substantially uniform gap outside of the one or more coils along the direction parallel to the center axes thereof, the first air cooling channel passing cooling air to air-cool the one or more coils.

A transformer configured for use in connection with a variable speed motor drive includes primary windings and secondary windings. The secondary windings are configured as wye-windings and a ground lead and a plurality of phase leads. The transformer includes a ferrite blocking circuit connected to the ground lead.

An apparatus includes a plurality of input nodes configured to receive a multiphase alternating current (AC) input signal. The apparatus further includes a plurality of inductors, a neutral terminal, a first plurality of output nodes, and a second plurality of output nodes. The plurality of inductors is coupled to the plurality of input nodes, and the neutral terminal is coupled to the plurality of inductors. The first plurality of output nodes is coupled to the plurality of inductors and is configured to output a first multiphase AC output signal. The second plurality of output nodes is coupled to the plurality of inductors and is configured to output a second multiphase AC output signal.

An apparatus includes a plurality of input nodes configured to receive a multiphase alternating current (AC) input signal. The apparatus further includes a plurality of inductors, a neutral terminal, a first plurality of output nodes, and a second plurality of output nodes. The plurality of inductors is coupled to the plurality of input nodes, and the neutral terminal is coupled to the plurality of inductors. The first plurality of output nodes is coupled to the plurality of inductors and is configured to output a first multiphase AC output signal. The second plurality of output nodes is coupled to the plurality of inductors and is configured to output a second multiphase AC output signal.

An electromagnetic device includes an outer peripheral iron core, and at least three iron core coils which are in contact with or coupled to the inner surface of the outer peripheral iron core. The at least three iron core coils each include an iron core, and at least one of a primary coil and a secondary coil, which are wound around the iron core. The at least three iron core coils are arranged in a circle, and the iron core of one of the at least three iron core coils is in contact with the iron cores of the other iron core coils adjacent to the one iron core coil.