A three-phase alternating current electric motor wherein when a number of pole pairs of a rotor is P and a number of slots in which stator windings are inserted is N, N/(6P) becomes an irreducible fraction with a value of a denominator of 4 or more and wherein the relation of N>3P stands, in which the motor, for the layout of one layer of windings arranged in the slots, the UVW three-phases are arranged so as to have rotational symmetry of ±120 degrees in terms of mechanical angle from each other and, for the layout of the second layer, the windings are arranged reversed in direction by 180 degrees in electrical angle from the phases of the first layer of windings which have rotational symmetry and offset by M number of slots from the first layer, where T is a particular odd number for the relationship of 4/35≦|T−2PM/N|≦ 8/35 is given.

A linear-motor stator assembly comprising a stator and an integral line reactor in one housing. The reactor has inductor coils which are connected in series with the stator windings to compensate for unequal inductances in the stator phases and balance the polyphase currents into the stator.

A linear-motor stator assembly comprising a stator and an integral line reactor in one housing. The reactor has inductor coils which are connected in series with the stator windings to compensate for unequal inductances in the stator phases and balance the polyphase currents into the stator.

A miniature step motor is constructed with a permanent magnet rotor and a hybrid stator assembly. The rotor, mounted for rotation on an axial shaft, has one or more rotor sections or pieces with a pair of magnetic poles on opposed circumferential surfaces of each piece. The stator assembly, with an inner diameter to receive the rotor, is formed from a stack of bipolar phase-stators positioned in different axial planes, each phase-stator interacting with a rotor section via a two-dimensional magnetic flux path that is independent of every other phase-stator in the stack. The at least one rotor section and the phase-stators have different amounts of rotor-stator rotational offsets at specified angles 180°/N relative to each other about the axial shaft, where N is the number of motor phases. The phase-stators can be mutually offset from one another, or the rotor sections can be mutually offset.

A miniature step motor is constructed with a permanent magnet rotor and a hybrid stator assembly. The rotor, mounted for rotation on an axial shaft, has one or more rotor sections or pieces with a pair of magnetic poles on opposed circumferential surfaces of each piece. The stator assembly, with an inner diameter to receive the rotor, is formed from a stack of bipolar phase-stators positioned in different axial planes, each phase-stator interacting with a rotor section via a two-dimensional magnetic flux path that is independent of every other phase-stator in the stack. The at least one rotor section and the phase-stators have different amounts of rotor-stator rotational offsets at specified angles 180°/N relative to each other about the axial shaft, where N is the number of motor phases. The phase-stators can be mutually offset from one another, or the rotor sections can be mutually offset.

Disclosed is a yoke-less mover of a homopolar linear synchronous machine. The yoke-less mover may include a cold plate having slots. Ferromagnetic cores are fixed to the cold plate. Each of the ferromagnetic cores may protrude through a respective one of the slots, creating gaps between the ferromagnetic cores. Armature windings are fixed to the cold plate. The armature windings may occupy the gaps between the ferromagnetic cores. The ferromagnetic cores of the yoke-less mover have better ferromagnetic utilization and lower weight. It also enables more flexible topologies in the armature windings.

An energy storage system (100) comprises a switched reluctance motor having a rotor (101) and a stator (102). The rotor is arranged to be capable of acting as a flywheel for storing energy. A casing (106) encloses the rotor and stator, and the rotor is supported for rotation on the casing. The energy storage system further includes a base (109) arranged to support the casing. The energy storage system is arranged such that, in use, the axis of the rotor is generally horizontal. An energy storage installation comprising a plurality of energy storage systems is also provided.

An external winding controlled two-degree-of-freedom bearing-free switched reluctance motor includes a stator and a rotor. An edge portion of the rotor includes rotor teeth. The stator includes an external winding and a stator core. The stator core includes four suspension teeth distributed in x and y directions on the same circumference of the radial outer side of the rotor and magnetism isolating bodies connected to two adjacent suspension teeth, each suspension tooth includes, along the axial direction of the rotor, a permanent magnet sheet and magnetically conductive sheets symmetrically connected to two sides of the permanent magnet sheet, torque teeth are connected to the inner walls of the magnetism isolating bodies, and torque windings are wound around the torque teeth. The external winding includes x-direction control cores connecting two suspension teeth in the x direction to form two x-direction symmetrical closed paths.

A switched reluctance motor is provided that prevents deformation or damage of a bridge member assembled on a rotor at high speed rotation of the rotor. The motor includes a stator having a plurality of magnetic pole protrusions with a coil wound thereon and a rotor having a plurality of magnetic pole protrusions. A bridge member is formed in a T-shaped sectional shape consisting of a roof portion, a leg portion, and a foot portion and buries a gap between the magnetic pole protrusions of the rotor in a state of being supported to the rotor at three places including the foot portion (4c) and opposite end portions of the roof portion. Additionally, end plates are configured to close opposite end portions of the rotor.

A synchronous reluctance motor includes a rotor and a stator surrounding the rotor. The rotator includes a rotatable shaft and magnetic flux barrier layers arranged radially. One of the magnetic flux barrier layers closest to the stator is filled with a conductor, and one of the magnetic flux barrier layers closest to the rotating shaft is a void.