An electronic brushless variable transformer. Variable autotransformers, use brushes, and as such, have moving parts requiring maintenance and periodic cleaning of the brushes. A variable transformer without brushes is advantageous in that it eliminates the cleaning and maintenance of brushes.

An embedded magnetic component transformer device includes an insulating substrate with a cavity and a magnetic core housed within the cavity. First and second electrical windings pass through the insulating substrate around the magnetic core. The first electrical winding includes a first end terminal and a second end terminal, and a first tap terminal between the first and second end terminals. The device includes circuitry with a first input terminal electrically connected to the first end terminal and a first output terminal. In a first configuration of the circuitry, the first output terminal is electrically connectable to the second end terminal. In a second configuration of the circuitry, the first output terminal is electrically connectable to the first tap terminal.

An isolation transformer boost system. The system includes a power supply and an isolation transformer. The isolation transformer includes a primary winding electrically connected to the power supply, a secondary winding, a first voltage tap, and a second voltage tap. Wherein the isolation transformer is configured to, in response to a command from an electronic processor, disconnect a connection from the second voltage tap and establish a second connection from the first voltage tap, wherein the command is based on an electrical characteristic measurement of the power supply exceeding an upper limit threshold for a predetermined period of time.

An electric machine is selectively operated as a transformer for AC voltage operation or as a throttle system for DC voltage operation. A transformer core has two limbs. An additional winding with a first additional partial winding is wound around a first limb and a second additional winding is wound around the second limb. A higher-voltage winding with a first higher-voltage partial winding is wound around the first additional partial winding and a second higher-voltage partial winding is wound around the second additional partial winding. A first traction winding is wound around the first higher-voltage partial winding and a second traction winding is wound around the second higher-voltage partial winding. A first DC voltage winding may be wound around the first traction winding and a second DC voltage winding may be wound around the second traction winding.

An electric machine is selectively operated as a transformer for AC voltage operation or as a throttle system for DC voltage operation. A transformer core has two limbs. An additional winding with a first additional partial winding is wound around a first limb and a second additional winding is wound around the second limb. A higher-voltage winding with a first higher-voltage partial winding is wound around the first additional partial winding and a second higher-voltage partial winding is wound around the second additional partial winding. A first traction winding is wound around the first higher-voltage partial winding and a second traction winding is wound around the second higher-voltage partial winding. A first DC voltage winding may be wound around the first traction winding and a second DC voltage winding may be wound around the second traction winding.

An arrangement for connecting a railway power supply for a railway track to a three-phase supply network. The arrangement has a three-phase AC transformer and a balancing device for a uniform electric load of the three phases of the three-phase supply network. The three-phase AC transformer is configured for connecting to the three-phase supply network on the primary side and is connected to the balancing device on the secondary side. The three-phase AC transformer is configured for connecting to a railway power supply which has an autotransformer system with two contact lines and two conductors that are carried along the railway track in an insulated manner.

The present patent application relates to a method and equipment for eliminating harmonics based on two complementary techniques, namely the elimination of harmonics by selective harmonic elimination pulse-width modulation in conjunction with the multiple-wiring transformer. The association of these two resources is capable of reducing the harmonic distortion of currents to extremely low values, providing a truly unitary power factor. The technology is suitable for low and medium intensity alternating current—direct current and direct current—alternating current converters, which make interface with the electricity network and should have low harmonic distortion of the current because of the high power value involved, and also because of fragility of the electricity network (low power of short circuit at the coupling point).

Shielding arrangements for transformer structures capable for operation in high frequency and high power density applications are disclosed. Electric shields may be incorporated within transformers to shield and/or redirect high strength electric fields away from areas of insulation material that may be prone to failure mechanisms. Such electric shields may be positioned between primary and secondary windings in order to be coupled with electric potentials of the windings. The electric shield may comprise a laminate structure that includes one or more metal layers and one or more dielectric layers, for example a printed circuit board. By positioning the electric shields in this manner, high electric fields associated with solid state transformer applications may be concentrated within planes of the electric shields and diverted away from potential problem areas, for example areas that are close to the windings where voids in the insulation material may otherwise promote failure mechanisms.

Shielding arrangements for transformer structures capable for operation in high frequency and high power density applications are disclosed. Electric shields may be incorporated within transformers to shield and/or redirect high strength electric fields away from areas of insulation material that may be prone to failure mechanisms. Such electric shields may be positioned between primary and secondary windings in order to be coupled with electric potentials of the windings. The electric shield may comprise a laminate structure that includes one or more metal layers and one or more dielectric layers, for example a printed circuit board. By positioning the electric shields in this manner, high electric fields associated with solid state transformer applications may be concentrated within planes of the electric shields and diverted away from potential problem areas, for example areas that are close to the windings where voids in the insulation material may otherwise promote failure mechanisms.

An electric power conversion apparatus according to an embodiment includes, wherein when a constituent element constituted of a leg in which two switching elements provided with self-arc-extinguishing capability are connected in series, and a capacitor connected in parallel with the leg is made a converter unit, and a constituent element formed by connecting one or more converter units in series is made a phase arm, a phase arm on the positive side, a single-phase four-winding transformer, and a phase arm on the negative side are included in each of three phases, one end of the phase arm on the positive side is connected to the positive side of a secondary winding of the four-winding transformer, and the other end thereof is connected to a DC positive side terminal.