The present disclosure provides a distributed phase-shifting transforming apparatus, including N transformer rectifier units, where each transformer rectifier unit includes two three-phase three-winding transformers and four rectifier circuits, each three-phase three-winding transformer includes first windings on the primary side and second windings and third windings on the secondary side, AC power output by the second windings and the third windings on the secondary side is output after being rectified by the rectifier circuits. Each transformer rectifier unit is configured such that: one set of the two first windings on the primary side and the two second windings on the secondary side is phase-shifted by 150 from each other, and the other set has the same phase angle; and the second windings and the third windings of each three-phase three-winding transformer are phase-shifted by 300 from each other. If N is greater than or equal to 2, the phase angle of the two first windings of the N.sup.th transformer rectifier unit can be obtained by respectively phase-shifting the phase angle of the two first windings of the (N−1).sup.th transformer rectifier unit by 15°/N. The distributed phase-shifting transforming apparatus has the advantages of small current harmonic distortion, simple process, low cost, high stability, and easy large-scale expansion.

An electric power system is provided that includes a three-phase to ten-phase step-up transformer. The transformer includes primary winding groupings, secondary windings, and third windings. The primary winding groupings include sub windings. Primary winding groupings are coupled to form a delta configuration and coupled to secondary windings and third windings, which may also be coupled to each other. The outputs at second ends of secondary windings and third windings are greater than the outputs at the second ends of primary windings. Diode pairs are connected to each other, each diode pair having an inner connection connected to one of the outputs of the transformer and first and second ends respectively connected to a positive dc bus and a negative dc bus. An inverter is connected to the d busses. The diode pairs operatively rectify the transformer output voltage to form a DC voltage with a reduced common mode voltage.

An electric power system is provided that includes a three-phase to ten-phase step-up transformer. The transformer includes primary winding groupings, secondary windings, and third windings. The primary winding groupings include sub windings. Primary winding groupings are coupled to form a delta configuration and coupled to secondary windings and third windings, which may also be coupled to each other. The outputs at second ends of secondary windings and third windings are greater than the outputs at the second ends of primary windings. Diode pairs are connected to each other, each diode pair having an inner connection connected to one of the outputs of the transformer and first and second ends respectively connected to a positive dc bus and a negative dc bus. An inverter is connected to the d busses. The diode pairs operatively rectify the transformer output voltage to form a DC voltage with a reduced common mode voltage.

A transformer coil structure includes a core defining an axis around which is wound a primary winding, and two secondary windings wound around the core over or under the primary winding. The windings are separated into two or more columns along the axial direction of the core by one or more gaps extending radially through the windings to the core.

A multi-phase shift transformer based AC-DC converter includes a single transformer that reflects a negative portion of an AC voltage to become a positive voltage by generating multiple phases from a poly-phase input. The multiple phases generated can be separated by as little as 1° to create a well-approximated DC output without the need for a smoothing circuit. The primary and second windings of the transformer are flat wire conductors structured to provide a larger number of windings per core including a larger number of secondary coils, which provides for a large number of output phases.

The present invention provides methods and apparatus for producing a variable and auto regulated three phase power source from an existing three, two or single phase power supply source. Variability and regulation are achieved by producing and controlling two of the three phase nodes/phasors by their amplitude and phase angle displacement. The combination of two independent variable power source inverters, with the incoming unregulated existing power supply source, produces a variable three phase power source in a Wye configuration, that achieves a variable stable and constant regulated Delta configuration three phase power source output.

The present invention provides methods and apparatus for producing a variable and auto regulated three phase power source from an existing three, two or single phase power supply source. Variability and regulation are achieved by producing and controlling two of the three phase nodes/phasors by their amplitude and phase angle displacement. The combination of two independent variable power source inverters, with the incoming unregulated existing power supply source, produces a variable three phase power source in a Wye configuration, that achieves a variable stable and constant regulated Delta configuration three phase power source output.

An auto transformer rectifier unit (ATRU) is provided. The ATRU comprises a transformer configured to receive a three-phase alternating current input and produce a ten-phase alternating current output, and a rectifier configured to receive the ten-phase alternating current output and output a bipolar direct current.

An auto transformer rectifier unit (ATRU) is provided. The ATRU comprises a transformer configured to receive a three-phase alternating current input and produce a ten-phase alternating current output, and a rectifier configured to receive the ten-phase alternating current output and output a bipolar direct current.

A power converter having a Scott-T transformer includes a direct current to alternating current converter configured to have at least two multilevel converters converting input direct current power to alternating current power, a Scott-T transformer configured to operate in medium frequency of several hundreds of Hz to several tens of kHz, to transform a voltage level of the alternating current power from each of the at least two multilevel converters of the direct current to alternating current converter into three-phase alternating current power, and to output the three-phase alternating current power, and an alternating current to direct current converter configured to convert the three-phase alternating current power from the Scott-T transformer to direct current power.