Abstract: It is an object to obtain a highly efficient and low-cost single-phase motor by producing the motor in a form that allows a proper material layout, with securing a magnetic path of a coreback of a stator iron core.

Abstract: A coil wire for a coil assembly of a rotating electrical machine is provided such that sufficient space in braiding is secured when coil-wire-bundles bundling a plurality of the coil wires are braided. Each of the coil wires has a predetermined length, a plurality of straight portions and a plurality of turn portions, the straight portions linearly-extend in parallel in a first direction substantially perpendicular to the overall length direction of the coil wires, the turn portions connect two of the straight portions to be adjacent via first-kinked-portions and second-kinked-portions, the first-kinked-portions are kinked in a second direction substantially perpendicular to both the first direction and the length direction of the coil wires, the second-kinked-portions are kinked in a third direction substantially opposite to the second direction so that the turn portions are formed in a wave-shape in the length direction of the coil wires.

Abstract: A stator for an electrical machine, in particular a rotary current generator, is proposed, in which the stator (36) is made by the flat-packet technique and comprises at least one stator iron (10) and a stator winding (30), and the stator iron (10) has a substantially annular-cylindrical shape, and the stator iron (10) has an axial direction (a) which is oriented in the direction of a cylinder axis, and the stator iron (10) has an end face, oriented in the direction of the cylinder axis and defining a slot area (ANut), and a ratio (A) formed of the slot area (ANut) and the end face area amounts to between 0.4 and 0.8.

Abstract: The electric rotating machine includes a rotor around which a field coil is wound, and a stator including a stator core around which an armature winding is wound. The armature winding includes a first three-phase winding whose phase coils are delta-connected to form a delta winding, and a second three-phase winding whose phase coils are connected to corresponding nodes of the delta winding to form a star winding. The delta winding and the star winding are wound around the stator core such that the phase coils of the delta winding and the phase coils of the star winding share the same slots of the stator core.

Abstract: The present invention relates to a two-phase brushless DC motor which can increase a pemerance coefficient of a rotor to the maximum to thereby improve efficiency and starting feature of the motor, and to reduce torque ripple and noise thereof. The brushless motor of the present invention includes a two-phase winding stator having 4×n winding poles and auxiliary poles provided between the winding poles, and a rotor constituted by 6×n permanent magnet rotating poles having divided angle. Auxiliary poles between the stator poles can be provided. The two-phase brushless motor of the present invention can be driven by a control device for the two-phase motor which can transform electric power and rectify electronically.

Abstract: The invention includes an electric alternator/motor having a rotor, stator and at least one winding in the stator adapted to conduct a current, the machine also having and first and second magnetic circuits, one of which includes a saturable portion in which saturation may be controlled to permit control of the machine.

Abstract: A stator for an electric rotating machine includes a stator coil that is formed of a plurality of electric wire segments each of which is comprised of an electric conductor and an insulating coat covering the electric conductor. The electric wire segments include a joined pair of first and second electric wire segments. Each of the first and second electric wire segments has an end portion of a first predetermined length where the electric conductor is not covered by the insulating coat. The end portions of the first and second electric wire segments are joined together. For each of the first and second electric wire segments, the insulating coat has, at its boundary with the end portion of the electric wire segment, a peeled portion of a second predetermined length which has a distal end peeled from the electric conductor and a proximal end remaining attached to the electric conductor.

Abstract: A stator for use in an electric rotating machine is provided which includes a stator winding wound through slots of a stator core. The stator winding is made up of a plurality of conductor segments connected together. Each of the conductor segments includes an in-slot portion disposed inside one of the slots and out-slot portions extending from the in-slot portion outside at least one of the ends of the stator core. Ends of the out-slot portions are joined together to form the stator winding. The joints of the ends of the out-slot portions have a given pattern of texture formed on surfaces thereof and coated with an insulating material. The pattern of texture enhances the adhesion of the insulating coatings to the surfaces of the joints and ensures the stability in electric insulation of the joints.

Abstract: A high-precision cylindrical coil having a high-precision fine coil pattern and a high mechanical precision such as fine roundness and no axial runout, and a cylindrical micrometer using the cylindrical coil are provided. In a cylindrical coil, a plurality of layers of coil patterns formed by filling the coil pattern grooves formed on a cylindrical substrate with a conductor and a plurality of insulating layers coating the cylindrical substrate are formed, the layers of coil patterns are electrically interconnected to each other by filling a through-hole formed by performing a hole forming process with a conductor, and the outmost layer is made of an insulating material.

Abstract: An insulating cover or a bar-to-bar connection of a stator winding of an electric machine has only one opening and is made from a flexible insulating material embedding the bar-to-bar connection entirely in a tight fit. Methods for producing and applying such an insulating cover are also provided.

Abstract: Provided are a radial core type brushless direct-current (BLDC) motor and a method of making the same, having an excellent assembly capability of division type stator cores in a double rotor structure BLDC motor. The BLDC motor includes a rotational shaft, an integrated double rotor including an inner rotor and an outer rotor, and a rotor supporter wherein a trench type space is formed between the inner rotor and the outer rotor, and an end extended from the inner rotor is connected with the outer circumferential surface of a bushing combined with the rotational shaft, and an integrated stator wherein one end of the stator is disposed in the trench type space and an extension axially extended from the other end of the integrated stator is fixed to the housing of the apparatus.

Abstract: In a rotor for a rotating electrical machine, a flange of an insulating bobbin is formed with a first hook portion and a second hook portion. The first hook portion directs a lead of a field coil both against the winding direction of the field coil and radially inward. The first hook portion has a first groove in which is hooked a proximal portion of the lead. The second hook portion directs the lead axially outward. The second hook portion has a second groove which has an open end on a radially inner periphery of the second hook portion, a closed end positioned radially outward of the open end, and a neck between the open and closed ends. The second hook portion has an intermediate portion of the lead hooked in the second groove between the neck and closed end of the second groove.

Abstract: The invention relates to a coil (1), in particular for an electric machine, in particular a transformator or an electromechanical converter, in particular an electric motor, for guiding an electric current for producing a magnetic field. Said coil consists of individual windings (2) that are essentially embodied as a flat body thus obtaining a tightly packed structure when the windings (2) are superimposed, and respectively, each winding (2) comprises at least one circulating conductor path with the exception of at least one electric interruption on one side. Said conductor path of a winding (2) comprises, on one point, an electroconductive connection with a conductor path of an adjacent winding (2). The windings (2) are incidentally, essentially electrically isolated to each other.

Abstract: A rotor provided in rotary electric machines comprises a stator core having a radial direction and slots provided with bottomed openings directed in the radial direction. The rotor also comprises a stator coil comprising slot accommodation portions being accommodated in the slots of the stator core and coil end portions each connecting mutually adjacent slot accommodation portions among the slot accommodation portions and respectively protruding from both end faces of the stator core. The stator coil is pre-formed into a cylindrical shape before the slot accommodation portions are accommodated into the slots of the stator core. The slot accommodation portions are formed to respectively have convex parts each protruding toward an opposite way to the slot openings, before the slot accommodation portions are accommodated into the slots. The convex parts are pressed by the stator core toward the openings during accommodation of the slot accommodation portions into the slots.

Abstract: When electric wires (joint conductors) are disposed adjacent each other in a peeled state of coatings, a gap corresponding to the total thickness of both conductors' insulating films as skin layers is formed between end joined face portions of the conductors. The gap becomes larger because the conductors are tapered. Therefore, the adhesion between both conductors is impaired, with a consequent fear of occurrence of joining imperfection. In opposed joined face portions of electric wires (joint conductors), the conductors are deformed from the tips of their axes to the joined face side in such a manner that exposed portions at the tips of the conductors and insulating film faces located in the vicinity thereof are flush with each other or the exposed portions are projected.

Abstract: A stator of a motor is provided with a stator core having a plurality of teeth and a plurality of windings wound around teeth of the stator core. The stator also has an insulator that is provided with a plurality of lead-out guide portions that enable lead-out wires of the windings to be drawn out from the tooth winding portions in a state of being close to the tooth winding portions.

Abstract: The invention relates to a stator for an electronically switchable electric motor comprising a cylinder-shaped envelop and several poles, which are made of an ferromagnetic material and inwardly oriented in front of the cylinder axis (3), wherein said poles (P1 to P12) surround a cylindrical cavity for receiving the rotor (2), each pole (P1 to P12) is provided with a coil (L1 to L12) consisting of several wire windings in such a way that a magnetic armature is formed and the windings of coils (L1 to L12) are wound about the poles (P1 to P12) successively and without interruptions.

Abstract: The present invention relates to an electric motor and to a method for manufacturing an electric motor. The electric motor comprises at least a stator (24), a rotor (25) and an air gap (26) between these, in which motor the stator and/or rotor comprises slots (4) and teeth (5) between slots, and in which the stator and/or rotor has a concentrated winding fitted in the slots. In the method of the invention, the phase windings are fitted as a concentrated fractional-slot winding.

Abstract: An apparatus for producing electrical power from mechanical power, includes a generator with a rotor and a stator for conversion of mechanical power to a polyphase alternating current having more than three phases. The stator has a stator core with a cylindrical stator bore and a plurality of parallel stator slots disposed at a distance from one another, extending axially along a length of the stator core and being open towards the stator bore. A plurality of stator winding bars are disposed in the stator slots so as to form delta-connected windings for producing the polyphase alternating current. A static frequency converter in the form of a matrix converter converts the polyphase alternating current to a desired output alternating current, wherein the stator is a polygonal stator having external winding connections that are bridged, wherein inputs to the matrix converter are connected to end connections of the winding bars.

Abstract: In a stator coil of a rotary electric machine, a first crank portion radially shifts one side of a turn portion from the other side thereof by a first length. The one side extends to one of paired straight portions, and the other side extends to the other thereof. A second crank portion radially shifts one side of a turn portion from the other side thereof by a second length. The one side extends to one of the paired straight portions, and the other side extends to the other thereof. The first length is equivalent to a radial width of the turn portion of the first segment of each set. The second length allows the second crank portion of the second segment of each of the sets to substantially overlay the first crank portion of the first segment of each set.

Abstract: An electric motor comprising a rotor having plural magnetic poles in the circumferential direction; and a stator whose teeth are disposed opposite to the periphery of the rotor, with an air gap interposed between the rotor and the stator, wherein the coil conductors are wound on the stator so that two stator magnetic poles may be formed by two coil units of a phase wound around stator teeth within the range of 360 electrical degrees subtended by the magnetic poles of the rotor; each of the two coil units forming the stator magnetic poles spans an electrical angle less than 180 electrical degrees; the two coil turns forming the two stator magnetic poles are laid out so that they may not overlap each other; and the coil conductors are so wound that the adjacent stator magnetic poles exhibit opposite magnetic polarities.

Abstract: A stator winding for a slotless motor is parallel with the longitudinal axis of the motor except at the end turns of the coil windings. The coils have concentrated windings with a pair of coils wired in series to form one phase of the stator windings. Each of the pair of coils are wound such that the magnetic flux produced by a dc current through the coils produces magnetic flux of opposite directions with respect to the rotor of the motor.

Abstract: A six lead, two speed, consequent wound, single phase induction motor with a tapped auxiliary winding having a 2-pole high speed mode and 4-pole low speed mode. A portion of the auxiliary winding is connected in series with the four pole main winding. The 4-pole low speed mode has an efficiency of over 80%.

Abstract: A rotary electric machine according to present invention comprises a rotor and a stator disposed around the rotor in which the stator includes a stator core having, along its inner periphery region, a plurality of axially extending stator slots and an armature winding wound through the stator slots. In this rotary electric machine, each stator slot contains four radially layered armature bars; each armature winding is formed by electrically connecting at least one of the armature bars in a first slot and at least one of the armature bars in a second slot to each other; and the armature bars of a pair specified in accordance with a required output voltage of the rotary electric machine are connected to each other with a connecting piece.

Abstract: A motor stator includes a silicon steel seat wound with six sets of starting coils and six sets of operating coils formed with resistant enameled coils. The six sets of starting coils are respectively made of the resistant enameled coils in directions respectively of entering into a first slot and out a fifth slot of the silicon steel seat, entering into a second slot and out a sixth slot, entering into a third slot and out a seventh slot, entering into an eleventh slot and out a seventh slot, entering into a twelfth slot and out an eighth slot, and entering into a first slot and out a ninth slot. And the six sets of operating coils are respectively composed of the resistant enameled coils in directions respectively different from the winding directions of the six sets of starting coils, able to quickly and evenly complete winding work.

Abstract: An electro-mechanical device that functions as a motor or a generator and methods for constructing and using such electro-mechanical device are provided. The electro-mechanical device features permanent magnets placed in a magnetically attracting manner and inter-dispersed between control coils. The control coils are energized to create a flux opposing the flux of the permanent magnets and to create a rotational torque on the poles of a salient pole rotor before those poles align with the poles of the energized control coil stator segment. Power can be generated by placing the flux of the control coils in a steady state and mechanically rotating the salient pole rotor. The electro-mechanical device provides little or no cogging forces, high-efficiency operation, and a high power density.

Abstract: An apparatus is provided for an electrical machine rotor. The apparatus comprises a cylinder and a first slot proximate to an edge of the cylinder. The first slot is at least partially closed. The apparatus further comprises a hairpin winding disposed within the first slot.

Abstract: A stator assembly includes a stator core and at least one conductive bundle. The stator core has a first end, a second end, and a plurality of slots extending from the first end to the second end. The conductive bundle includes a plurality of individually insulated conductive wires. At least one portion of the at least one conductive bundle extends from the first end to the second end of one slot of the plurality of slots. The at least one portion is twisted by a predetermined amount within the one slot to minimize a circulatory current along the plurality of individual insulated conductive wires in the at least one portion.

Abstract: An electric motor core member includes a body having an inner diametric portion including an inner arcuate surface and an outer diametric portion including an outer arcuate surface. The electric motor core member further includes a plurality of wall members provided on the main body. Each of the plurality of wall members projects outwardly from the outer arcuate surface and is arranged in a spaced relationship to define a plurality of conductor isolation channels. Each of the plurality of conductor isolation channels is adapted to receive one of a plurality of conductors with the plurality of wall members providing electrical isolation between adjacent ones of the plurality of conductors.

Abstract: A permanent magnet (PM) electric generator with directly controllable field excitation control comprises: a drive shaft; a PM rotor assembly with multiple PMs arranged around an outer axial periphery of the rotor assembly; a stator assembly comprising a ferromagnetic stator yoke, multiple ferromagnetic stator teeth mounted to the stator yoke with distal ends proximate the outer axial periphery of the rotor assembly separated by an air gap and multiple stator coils mounted between the stator teeth; multiple saturable ferromagnetic shunts, each shunt coupling adjacent distal ends of the stator teeth to shunt air gap magnetic flux ?g generated by the PMs across the air gap through the distal ends of the stator teeth; and multiple saturation control coils, each saturation control coil wrapped about a saturable region of an associated one of the shunts; wherein application of a control current Ic to the control coils at least partially magnetically saturates the shunts to reduce shunting of air gap magnetic flux ?

Abstract: Rotational electric machine stator winding arrangement characterized, inter alia, by at least one coil of each parallel circuit being discontinuous with the other coils of the corresponding circuit, and by coils configured to accept phase voltage not being adjacent coils having a point at the lowest potential of a corresponding circuit.

Abstract: In a stator winding, series coils are connected in parallel. One series coil includes series-connected U phase coils that are wound oppositely in direction by turns in the order in which the coils are series-connected and that are arranged in the manner that one and the other coil sets of the U phase coils are separated in the circumferential direction of a stator core and are opposite to each other in the radial direction thereof. The other series coil includes series-connected U phase coils that are wound oppositely in direction by turns in the order in which the coils are series-connected and that are arranged in the manner that one and the other coil sets of the U phase coils are separated in the circumferential direction of the stator core and are opposite to each other in the radial direction thereof.

Abstract: An electric motor comprising a rotor having plural magnetic poles in the circumferential direction; and a stator whose teeth are disposed opposite to the periphery of the rotor, with an air gap interposed between the rotor and the stator, wherein the coil conductors are wound on the stator so that two stator magnetic poles may be formed by two coil units of a phase wound around stator teeth within the range of 360 electrical degrees subtended by the magnetic poles of the rotor; each of the two coil units forming the stator magnetic poles spans an electrical angle less than 180 electrical degrees; the two coil turns forming the two stator magnetic poles are laid out so that they may not overlap each other; and the coil conductors are so wound that the adjacent stator magnetic poles exhibit opposite magnetic polarities.

Abstract: A straight line portion of a substantially U-shaped angular wire having a substantially rectangular cross section and a straight line portion of a substantially U-shaped round wire having a substantially circular cross section are accommodated at a slot arranged at a stator of a motor. The round wire is arranged at a more radially inward portion of the slot than the angular wire is. The connecting portion of the round wire is arranged radially inwardly of the straight line portion thereof. The connecting portion of the angular wire is arranged radially outwardly of the straight line portion thereof.

Abstract: A linear motor for high velocity drive has a transformer which has a magnetic circuit with a central limb; the two ends of stacked unit- or fractional-turn secondary winding of the transformer project at an angle to the longitudinal axis of the central limb; an armature links the two ends, sliding parallel to the longitudinal axis. The armature has dielectrics to form two series-connected capacitors in conjunction with the two ends. The transformer's primary winding is connected to an ac or pulse power source. The resonant frequency for the LC circuit formed by the two capacitors in series to the total effective inductance of the power source, the electric transformer and the armature is determined. The frequency or the pulse rise time of the power source is matched to the resonant frequency, in order to supply adequate electric power from the power source to the series LC circuit.

Abstract: A method to hook a magnet wire extracted from a coil A stator core 35 includes a core back 352 of a substantially annular shape. At a radially outer end portion of the core back 352 four teeth 351 are arranged radially. At the teeth 351, a coil 371 is formed by winding a magnet wire 37 via an insulator 36. A first insulator 361 configuring a lower half of the insulator 36 includes a first core back insulating portion 3611, 1 first teeth insulating portion 3612, and a first cylindrical portion 3613. A hook portion 4 is formed at the first core back insulating portion 3611 at radially outer side, and between the teeth 351. The magnet wire 37 extracted from the coil 371 is hooked on the hook portion 4. The magnet wire 37 hooked on the hook portion 4 is lead the magnet wire 37 around the hook portion 4 as a base, and is soldered to a land 381 formed above a circuit board 38.

Abstract: A motor includes: a rotor in which 10 poles are magnetized at regular intervals; a stator having 12 core pieces and facing the rotor, all core pieces having a concentrated winding wound in the same direction and being annularly arranged; and a wiring board for making 3-phase connection of the windings. A wire connection is made through the wiring board in such a manner that electric currents of adjacent same phase windings flow in opposite directions and of electric currents of adjacent different phase windings flow in same directions.

Abstract: An electromechanical power converter that has a rotor assembly with a conductive shell, a first conductor made from superconducting material that is in series electrical contact with the conductive shell and a second conductor made from superconducting material and in series electrical contact with said conductive shell, thus providing an internal impedance converting electromechanical power converter.

Abstract: The invention relates to a direct drive for large-scale drives, comprising a stator (1) which is configured, when seen from the peripheral direction, by a plurality of segments (3, 4, 5, 6), each having a self-contained winding arrangement, and a rotor which is configured from segments. The segments of the rotor are located on working elements that rotate with the rotor, and interact electromagnetically with a winding system of the stator (1). The inventive drive is especially suitable for ring motors and tube mill drives.

Abstract: A plurality of salient poles projecting toward a stator are arranged on a rotor core along the circumferential direction while being spaced apart from each other, and rotor windings are wound around these salient poles. The rotor windings are short-circuited through diodes, respectively; and when currents rectified by the diodes flow through the rotor windings, the salient poles are magnetized to produce a magnet where the magnetic pole is fixed. The width ? of each salient pole in the circumferential direction is smaller than a width corresponding to an electric angle of 180° of the rotor, and the rotor windings are wound around each salient pole by short-pitch winding.

Abstract: A total number of windings in an armature is an even number. The windings are divided into a first winding group and a second winding group. The windings of the first winding group are arranged one after another at generally equal angular intervals without overlapping with each other. The windings of the second winding group are arranged one after another at generally equal angular intervals without overlapping with each other and are wound separately from the windings of the first winding group.

Abstract: A rotor pole crossover connection joint for use in a rotating electrical machine is disclosed. The connection joint integrally couples a bottom rotor coil strap to a rotor pole crossover connector with a single piece connector that reduces, distributes or otherwise tolerates stress concentrations in the connector. A corresponding method of forming a rotor pole crossover connection and a rotor assembly including a rotor pole crossover connection joint are also disclosed.

Abstract: A resolver includes a stationary unit centered about a center axis, and a rotary unit disposed inside or outside the stationary unit to be rotatable around the center axis with respect to the stationary unit. The stationary unit includes teeth radially arranged around the center axis, and an insulator covering surfaces of the teeth. The stationary unit further includes output coils formed on the teeth by winding at least one of two output wires around each of the teeth via the insulator in a first number of turns and in multiple layers, and excitation coils formed on the teeth by winding an excitation wire around the output coils in multiple layers and in a second number of turns less than the first number of turns.

Abstract: The present invention is intended to provide a winding arrangement of single star connection for a rotating electrical machine, capable of enhancing insulation performance in coils of the same phase. In such winding arrangement, a first coil U1 to a sixth coil U6 are formed respectively in coil arranging parts 1U to 6U. Next, a coil arranging part 7U is skipped and the seventh coil U7 is formed in a coil arranging part 8U. Then, a coil formed at the end of winding (eighth coil U8) is formed in the skipped coil arranging part 7U.

Abstract: A permanent magnet (PM) dynamoelectric machine with directly controllable field excitation control comprises: a drive shaft; a PM rotor assembly with multiple PMs arranged around an outer axial periphery of the rotor assembly; a stator assembly comprising a ferromagnetic stator yoke, multiple ferromagnetic stator teeth mounted to the stator yoke with distal ends proximate the outer axial periphery of the rotor assembly separated by an air gap and multiple stator coils mounted between the stator teeth; multiple saturable ferromagnetic shunts, each shunt coupling adjacent distal ends of the stator teeth to shunt air gap magnetic flux ?g generated by the PMs across the air gap through the distal ends of the stator teeth; and multiple saturation control coils, each saturation control coil wrapped about a saturable region of an associated one of the shunts; wherein application of a control current Ic to the control coils at least partially magnetically saturates the shunts to reduce shunting of air gap magnetic fl

Abstract: An electrical induction motor has a main winding formed with two electrical conductors having different electrical resistivities. The motor includes a stator having a structure about which a winding is formed, and the winding includes a first electrical conductor having a first end and a second end, and a second electrical conductor having a first end and a second end, the first end of the first electrical conductor and the first end of the second electrical conductor being coupled together and the second end of the first electrical conductor and the second end of the second electrical conductor being coupled together to form a parallel circuit with the first electrical conductor and the second electrical conductor, and the second electrical conductor having an electrical resistivity that is greater than an electrical resistivity of the first electrical conductor. In one embodiment, the first electrical conductor is copper and the second electrical conductor is aluminum.

Abstract: The invention relates to a power storage system intended to transmit power to and from a driving system of a vehicle. A power storage having a stator provided with two windings and at least one rotor provided with a magnetic-flux generating device is comprised. The rotor is connected to a flywheel intended for storage of energy. The two windings of the stator are arranged for high and low voltage, respectively. The power storage is arranged to transmit power to and from the electric apparatus as well as store energy transmitted from the electric apparatus in the flywheel.

Abstract: In a rotary electric machine, a field coil member includes a first edgewise coil composed of a plurality of coaxially layered convolutions. The coaxially layered convolutions are wound around the outer periphery of the first pole core. The field coil member includes a second edgewise coil composed of a plurality of coaxially layered convolutions. The coaxially layered convolutions are wound around the outer periphery of the second pole core. The field coil member includes a link portion connecting between the first edgewise coil and the second edgewise coil in series. One of the first and second edgewise coils has one coil end extending therefrom to cross over the link portion at a crossover portion thereof. The crossover portion between the one coil end and the link portion is arranged to be non-overlapped with the convolutions of the one of the first and second edgewise coils.

Abstract: A high speed aircraft generator may utilize a prefabricated crossover subassembly to interconnect field coils. The crossover may include two attachment leads interconnected with a section of braided wire. The braided wire may remain free of brazing filler metal after the crossover subassembly is brazed into position between field coils of the generator. Consequently, the crossover may remain flexible and may have reduced susceptibility to fatigue failure that may otherwise result from circumferential relative displacement of the field coils from one another during changes of rotational speed of the field coils.

Abstract: An electric rotating machine comprising a stator core having a plurality of slots that are equally spaced on the inner surface of the stator core in the peripheral direction, a rotor that rotates inside the stator core, and an armature winding that is applied to each of the slots, wherein the armature winding is made up with a plurality of serially-connected single-turn coils that are respectively applied to the slots and the serially-connected coils of respective phases are connected in parallel.