Auto balancing transformers are disclosed for balancing a multi-phase electrical system by varying the degree of electromagnetic coupling between primary and secondary winding. The auto-balancing transformer includes a movable to selectively couple primary phases with two or fewer phases of the secondary system.

An autotransformer for converting three-phase AC power to nine-phase AC power. The autotransformer includes three coils each having serial connected windings and non-serial connected windings. The combination of the serial and non-serial windings are interconnected to form a polygon for a total of six windings per phase, in an arrangement which reduces the power rating of an autotransformer suitable for 18-pulse AC to DC power converters. There are a plurality of direct outputs that are equal in magnitude and are out of phase with respect to the voltages at the input. The input is offset from the nine outputs to create the required phase magnitudes for DC power converters.

The present techniques are related to a system and method for increasing the magnetic flux applied to a magnetic shape-memory (MSM) element. The method includes generating a magnetic field by applying a current through a transformer core. The method includes directing the magnetic field to configure a position of the MSM element. The method includes propagating the magnetic field through a ferrofluid at an interface between the transformer core and the MSM element. The method also includes increasing the permeability of a magnetic flux of the magnetic field across the MSM element.

A quad-T transformer in some embodiments includes a first split winding, a second split winding, and two orthogonal closed-loop windings coupled between the first split winding and the second split winding. Wires can be wound around magnetic cores. A first of the two orthogonal closed-loop windings is coupled to a first portion of each of the first split winding and the second split winding. A second of the two orthogonal closed-loop windings is coupled to a second portion of each of the first split winding and the second split winding. A bi-directional single-phase/three-phase converter includes the quad-T transformer and a Scott-T transformer with an output connected to a three-phase connection. The Scott-T transformer also has a 90-degree input connected to the quad-T transformer and a zero-degree input connected to a single-phase connection.

A pair of phase shifted polygon primary windings, each of which are magnetically coupled to one of a pair of forked wye output windings providing a phase shifted pseudo multiple pulse output voltage waveform from the secondary output windings.

A pair of phase shifted polygon primary windings, each of which are magnetically coupled to one of a pair of forked wye output windings providing a phase shifted pseudo multiple pulse output voltage waveform from the secondary output windings.

A three-phase autotransformer including three output groups and three inputs each connected to each of the outputs of a respective output group by windings, the windings being configured so that, when each input has a respective input voltage applied thereto, the three input voltages having the same input amplitude, being 120° out of phase with each other and defining a neutral point: for each output group, a main output voltage, taken between a main output of said output group and the neutral point, has an amplitude greater than the input amplitude; and output voltages of the autotransformer belong to a same Reuleaux polygon, each output voltage being associated with a respective output and being equal to a voltage between said output and the neutral point.

Auto-balancing transformers are disclosed for balancing a multi-phase electrical system by varying the degree of electromagnetic coupling between primary and secondary windings. The auto-balancing transformer includes a movable armature to selectively couple primary phases with two or fewer phases of the secondary system.

Auto-balancing transformers are disclosed for balancing a multi-phase electrical system by varying the degree of electromagnetic coupling between primary and secondary windings. The auto-balancing transformer includes a movable armature to selectively couple primary phases with two or fewer phases of the secondary system.

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.