Abstract: A triple core transformer including a coupler connected to a third core between two primary windings. Two sets of twisted pairs are wound around each primary core such that a strand of each pair communicates with primary each core. One strand of each pair is wound denser than the complementary strand of that pair. The denser strands are connected to a third winding around the third core. The third winding is wound in a series of segments. Each of the segments is connected to the preceding segment in a wire twist.

Abstract: A phase shifting transformer or autotransformer for a three phase power distribution network has a secondary winding including a plurality of windings distributed amongst the three core legs such that on each core leg the number of turns of windings generating a flux in the positive direction is substantially equal to the number of turns of windings generating a flux in the negative direction. Thus, according to the invention, the transformer may be provided with any necessary phase shifting angles between different harmonic sources, with outputs each having a very low zero phase sequence impedance to reduce voltage distortion created by zero phase sequence harmonics.

Abstract: A three phase transformer having a pair of additional coupled windings on the secondary side of each phase, with these coupled windings properly connected in series to develop a voltage in phase with a particular secondary voltage but driven from alternate phase primaries. The primary and secondary windings are connected in a Y or .DELTA. configuration. One coupled winding from each of the two phases, other than the desired secondary phase which is to be balanced, are joined in negative series so that when summed, they are aligned with the secondary phase being corrected. The series coupled windings are connected in parallel with the third secondary. The unbalanced current is split between the secondary winding and between the two coupled windings, each of which is coupled to the primary of another phase. The coupled winding combined voltages and resistances are approximately equal to the voltage and resistance of the secondary.

Abstract: A phase shifting polygonal transformer or autotransformer for a three phase electrical distribution system is provided, in which the transformer output winding or autotransformer winding is composed solely of three main coils and three auxiliary coils, alternately interconnected in series. The outputs for the transformer/autotransformer are connected to taps in the coils offset from the connections between coils, which eliminates the need for multiple auxiliary coils in each phase. The transformer/autotransformer of the invention is thus much simpler and less expensive to manufacture than a conventional phase shifting transformer or autotransformer, but reduces harmonics just as effectively.

Abstract: A transformer comprising a core, a plurality of primary coils and a plurality of secondary coils, the core having three sections arranged in a generally triangular configuration forming three vertices, the coils being disposed on the core about respective vertices, each of the core sections having at least one mitered side abutting a mitered side of an adjacent core section.

Abstract: An electro-magnetic device for use in applications requiring low-profile components. The device includes a magnetic substrate with a scheme of through-holes in association with a first and second winding, plated or wired, integral to the substrate and wound orthogonal to each other. The first winding comprises the AC inductor/transformer permeability. The second winding in association with an applied DC bias current causes the permeability to vary over a wide controlled operating range.

Abstract: A monolithic high-Q inductor structure is formed with multiple metalization levels in a conventional integrated circuit technology in which inductor turns utilize these multiple levels to reduce the inductor resistance. Inductors with Q values above five can be integrated with this approach at radio and microwave frequencies.

Abstract: An electrical power distribution transformer of the delta/wye configuration wherein the wye secondary windings are connected in a zigzag configuration and distributed among the legs of a multi-legged transformer core to achieve substantial attenuation of flux produced by undesired triplen harmonic (third and its multiples) currents arising from non-linear loads. The transformer also achieves a substantial reduction in capacitive coupling between the primary and secondary winding by means of an electrostatic shield positioned between the primary and secondary windings and by means of a metallic ground plane positioned as a barrier between the primary and secondary terminals.

Abstract: A power transformer for cycloconverters comprises an iron core having three legs, nine positive group windings, nine negative group windings, and nine power supply windings. Three of the positive group windings, three of the negative group windings and three of the power supply windings are wound on each leg of the iron core. In application to the cycloconverters, three positive and negative group windings are allotted to each of three converters of the cycloconverter so that the three-phase AC voltages are applied to the three converters respectively. The three power supply windings are allotted to each pair of positive and negative group windings so that a winding circuit impedance becomes equal between the positive and negative group windings. These windings are arranged into a single transformer in which the windings are magnetically connected together by one three-leg core.

Abstract: A summing transformer for a star-delta inverter having a separate secondary winding for each primary winding for use in inverting variable frequency AC power into constant frequency AC power, the transformer comprising a plurality of core sections having principal legs on which primary windings are wound and secondary legs extending between adjacent said principal legs establishing shared flux paths.

Abstract: A summing transformer for a star-delta inverter having a single secondary winding for each group of primary windings for use in inverting variable frequency AC power into constant frequency AC power, the transformer comprising a plurality of core elements having principal legs on which primary windings are wound and secondary legs extending from said principal legs establishing flux paths, the legs of each core element defining apertures through which a single winding is magnetically linked to a group of primary windings.

Abstract: A summing transformer includes first and second sets of primary windings, first and second sets of secondary windings inductively linked with the first and second sets of primary windings and a set of tertiary windings inductively linked with one of the first and second sets of secondary windings wherein the tertiary windigs are connected together and permit zero sequence currents to flow during a period of unbalanced load currents in the sets of secondary windings whereby the output voltages produced thereby are maintained in a substantially balanced condition during such period.

Abstract: A phase-shifting transformer including main and series transformer units comprises a six-phase core including six independent magnetic circuits, numbered first through sixth from right to left. The combined U-, V-, and W-phase windings of the main transformer unit link with the fifth, third, and first magnetic circuits, respectively. The combined a-, b-, and c-phase windings of the series transformer unit link with the sixth, fourth, and second magnetic circuits. The winding directions of the V- and b-phase windings are reversed with respect to those of other phase windings. Thus, if three-phase voltages 120 degrees apart are input to the main transformer unit, then the phase angles between the main magnetic fluxes generated in any two adjacent magnetic circuits are equal to 30 degrees.

Abstract: A three-phase transformer for a cycloconverter comprising three primary windings to which three-phase currents of U-, V- and W-phase are individually applied as inputs, and six secondary windings which are provided for each of the primary windings and so arranged that D.C. components contained in six sets of three-phase signals delivered from the secondary windings are canceled in the respective phases, thereby to prevent D.C. components from being contained in currents which are supplied to the primary winding wound around the main legs of an iron core for the respective phases.

Abstract: A variable transformer, reactor having a core combining at least two complete core elements wiht a common yoke; primary winding divided into two independently fed sets of phase coils wound in opposite direction, arranged on symmetrical legs of core elements and separated by the common yoke; secondary winding with each phase coil divided into two wound in opposite direction portions carried by symmetrical core legs, adjacent to the primary coils and separated by common yoke. The secondary short-circuited reactor winding is reduced to at least one close loop member with loop portions separated by the common yoke. The single, polyphase apparatus has at least one primary coil per set that includes a controllable device in circuit relation therewith to enable control of one primary coil relative to the other, either in current magntidue or in current phase shift. The controllable device being either a silicon control rectifier, triac or transistor.

Abstract: A rectifier transformer for supplying a predetermined alternating current to a rectifier includes: a transformer having secondary windings (cell windings) connected in a double star in such a manner that common terminal side conductors of the secondary windings are individually drawn out; and an interphase reactor having three iron cores, one of which is provided or each individual phase, primary windings formed by passing the conductors connected to two ends of the individual cell windings through the corresponding iron cores, and secondary windings wound around the corresponding iron cores in such a way that they are inductively coupled to the primary windings, the secondary windings being connected to each other in series so as to form a closed circuit.

Abstract: A rotating flux transformer having at least two magnetic cores, each in the form of a torus, with each magnetic core having poloidal and toroidal windings. The need for breaking the torus and bringing out leads from the poloidal winding is eliminated by passing each torus through the core window of the remaining torus, or tori. Each poloidal winding is shorted, with the toroidal winding, or windings, of the other magnetic core or cores, inducing an excitation voltage into each shorted poloidal winding which is 90.degree. out of phase with the voltage applied to the toroidal winding on the same magnetic core.

Abstract: A rotating flux transformer which includes a magnetic core having poloidal primary and secondary windings and toroidal primary and secondary windings. Quadrature flux is produced in the magnetic core by connecting one end of the poloidal primary winding to the center of the toroidal primary winding. The quadrature flux combines vectorially to produce a rotating induction vector in the magnetic core.

Abstract: A three phase core form transformer for use in a three phase dual dynamic stabilizer system that provides reactive power compensation. The transformer has a three legged magnetic core, a plurality of primary windings corresponding to the phases, two auxiliary secondary windings per phase that are wound to provide first and second common bifilar portions, and a plurality of principal secondary windings corresponding to the number of primary windings. The first common bifilar portion, the principal secondary winding, the second common bifilar portion and the primary winding are placed coaxially and radially adjacent, in the recited order, starting from each leg of the magnetic core.The primary windings are connected in delta. The principal secondary windings and auxiliary secondary windings are connected in a forked wye wherein one auxiliary secondary winding of each of the other two phases is electrically connected to the free end of each of the wye connected principal secondary windings.

Abstract: The present invention relates to a structure of neutral point of multiphase transformers for large secondary currents. Such multiple phase transformers, usually three phase transformers, are used for example for the operations of arc furnaces, and the secondary current of the transformer may amount to several thousand ampere. The neutral point is made as a plate (24) of material with good electric conductivity and is located within the transformer tank (27). Between the neutral point plate (24) and the tank wall (27) there is located a plate (25) of a material with good conductivity and serving as a screen for reducing losses in the tank wall (screen plate). The transformer is star connected on the secondary side. Each phase of the secondary winding consists of several windings connected in parallel, and the tappings are passed as parallel conductors onto the neutral point plate (24).

Abstract: A compact air cooled transformer employs multisection, multilayered high voltage coils in a wye connection to substantially reduce the spacing required between the high voltage coil and low voltage coil and between the ends of the high voltage coil and the transformer core yokes and coil support structure.

Abstract: A three-phase transformer structure has a double-window magnetic structure with an independent flux path encircling each window and an outer flux path encircling both windows. A shunt path for the outer flux path bridges both windows and two additional shunt paths bridge each window independently. Hence, each flux path has an independent and isolated shunt permitting operation of the three-phase transformer in a ferroresonant mode.

Abstract: A high current furnace transformer is provided having the low-voltage windings arranged in a closed delta configuration within the transformer enclosure. Bus bar terminals are mounted exterior to the enclosure for providing electrical connection with the low-voltage windings.

Abstract: An improved multiphase series reactor consisting of a number of interconnected coils, each coil being formed from sub-coil wherein the sub-coils consist of a number of laterally-spaced single-plane spirals, each spiral being formed from hollow electrical-conducting material. Each sub-coil is wound in such a manner that electrical power supplied to the coils passes through the constituent spirals of the sub-coils in the same direction. Coolant introduced into the interior of the hollow-electrical conducting material passes through the spirals of the sub-coils before being withdrawn.

Abstract: Apparatus for supplying direct current from a three-phase alternating-current source, comprising a three-phase A.C. transformer; one end of each transformer phase leg being connected via separate yokes to corresponding ends of the other two phase legs, while the respective other ends are interconnected via a common yoke. Individual leg coils are provided on the legs of the thus formed core, while pairs of yoke coils are arranged on the separate yokes. Respective ends of all the yoke coils are interconnected in pairs, and their other ends are connected to input terminals of a six-pulse, three-phase half-wave rectifier unit.

Abstract: An improved saturable reactance transformer having a main core and a pair of adjacent auxiliary cores is disclosed. The auxiliary cores carry DC control windings which regulate the reactance of the main core which carries the secondary, or output windings of the transformer. The primary winding is wound around all three cores, with the amplitude of the control voltage applied to the control windings regulating the output of the secondary windings. To prevent high voltage stresses in the transformer, each control winding is split into two or more windings, with the two windings being wound concentrically on their common core to reduce the voltage induced by the alternating current in the primary windings. In addition, the windings on the two auxiliary cores are cross-connected in pairs to equalize the reactance of each pair, thereby balancing the induced voltages.

Abstract: A saturated reactor adapted for direct connection to an EHV line and thus constituting a combined reactor and transformer. A problem arises in that earthing of the primary winding star point would normally short circuit the 3rd harmonic. The invention overcomes this by series connection of primary coils coupled to three limbs whose fluxes are spaced at 40.degree.. 3rd harmonic voltages therefore cancel in the series primary windings. The series primary windings may be obtained as separate coils on individual limbs or as one coil (per phase) embracing three limbs. Elimination of the 3rd harmonic enables the ninth harmonic to be short circuited in a mesh winding.

Abstract: Current transformers are utilized to combine the outputs of two 30.degree. phase shifted inverters to produce a three phase output which is low in fifth and seventh harmonics. The arrangement utilizes transformers having volt-ampere ratings which are very low compared to the power output of the inverters. The circuit may also be used to convert a three phase input to a multi-phase full wave rectified output without reflecting high fifth and seventh harmonics back into the line.

Abstract: A rotatable shaft has a roller electrode mounted on it for rotation therewith. A transformer and a rectifier are structurally integrated to form a unit which is also mounted on the shaft for rotation with it, and serve to convert high-voltage low-amperage net current into low-voltage high-amperage DC current. Slip rings are mounted on the shaft to transmit electrical current to the unit for supply to the roller electrode.