A permanent magnet for a motor, a rotor assembly having the permanent magnet, a motor, and a compressor are disclosed. The permanent magnet has a Nd—Fe—B-based main phase. The main phase has a grain size of smaller than or equal to 4 micrometers. The mass ratio of dysprosium and/or terbium in the permanent magnet is less than or equal to 0.5%. The intrinsic coercivity Hcj of the permanent magnet at 25° C. satisfies Hcj≥1500 kA/m. The permanent magnet according to embodiments of the present disclosure can have fewer or no heavy rare-earth elements, and meanwhile exhibit excellent performance, which improves the cost performance.

A permanent magnet for a motor, a rotor assembly having the permanent magnet, a motor, and a compressor are disclosed. The permanent magnet has a Nd—Fe—B-based main phase. The main phase has a grain size of smaller than or equal to 4 micrometers. The mass ratio of dysprosium and/or terbium in the permanent magnet is less than or equal to 0.5%. The intrinsic coercivity Hcj of the permanent magnet at 25° C. satisfies Hcj≥1500 kA/m. The permanent magnet according to embodiments of the present disclosure can have fewer or no heavy rare-earth elements, and meanwhile exhibit excellent performance, which improves the cost performance.

Methods, systems, and mechanical and electromechanical arrangements for field-weakening of an electric machine that utilizes permanent magnets are disclosed herein. One rotor assembly for an electric motor includes a rotor body that moves with respect to a central axis, the rotor body having a core and a number of permanent magnets that move with the rotor body, and the rotor body also having a number of movable field-weakening magnetic materials that move with respect to the permanent magnets and to the central axis.

A gas turbine engine which includes an outer casing; a central longitudinal hollow shaft with a forward air inlet; a three stage rotating superconducting electric bypass fan with front and rear fan blades and a diffuser blade interposed between said front and rear fan blades wherein the diffuser blade rotates in an opposite direction to the front and rear fan blades; a multiple stage superconducting axial compressor positioned aft of the three stage rotating superconducting electric bypass fan; a multiple stage superconducting electric turbine core positioned aft of the multiple stage variable speed superconducting axial compressor, whereby the electric power from the multiple stage superconducting electric turbine core powers the three stage superconducting electric bypass fan and the multiple stage superconducting axial compressor.

An electric machine is provided. The electric machine defines a centerline and includes: a stator assembly; a rotor assembly rotatable relative to the stator assembly about the centerline; and an actuator coupled to the rotor assembly, the stator assembly, or both for moving the rotor assembly, the stator assembly, or both along the centerline between a first position and a second position, the rotor assembly positioned closer to the stator assembly when in the first position than when in the second position.

A power apparatus, power assembly, energy assembly or energy apparatus that stores and disperses energy, the power assembly including: (1) a first and second energy object that experiences movement so as to store kinetic energy in the energy object, the energy object including a magnet assembly through which electrons are driven resulting in electric output from the magnet assembly, and the electric output dependent on experienced EMF (electro-motive force) that is experienced by the magnet assembly. The power assembly can include a switch assembly adapted to perform switching to switch between a first arrangement in which the first positive output is connected to the second positive output, and a second arrangement in which the first positive output is connected to the first negative output, and such second arrangement provides increased energy output relative to the first arrangement. A flip assembly can be provided that performs flipping of output energy.

In accordance with at least one aspect of this disclosure, a method can include measuring a voltage across a DC link of a generator system when a generator exciter is inactive and a generator permanent magnet is active, and detecting a short or open permanent magnet generator (SOPMG) fault condition in the generator system with a DC link monitor operatively connected to measure the voltage across the DC link.

In accordance with at least one aspect of this disclosure, a method can include measuring a voltage across a DC link of a generator system when a generator exciter is inactive and a generator permanent magnet is active, and detecting a short or open permanent magnet generator (SOPMG) fault condition in the generator system with a DC link monitor operatively connected to measure the voltage across the DC link.

An electric machine for a vehicle, comprising a stator, and a rotor comprising a plurality of poles, where each pole comprises a first V-shaped flux barrier and a second V-shaped flux barrier, where the first V-shaped flux barrier comprises two magnets with inner air cavities and outer air cavities, where the second V-shaped flux barrier comprises two magnets with inner air cavities and outer air cavities, and where the first and second V-shaped flux barriers are arranged adjacent each other and symmetrically to a d-axis of the rotor, where each of the poles further comprise a first V-shaped flux redirector arranged symmetrically to the d-axis and between the first V-shaped flux barrier and the second V-shaped flux barrier.

The invention relates to a permanent magnet motor, comprising: a stator configured for generating a time-varying magnetic field; a rotor, arranged inside of the stator, comprising at least one permanent magnet providing a constant magnetic field; the permanent magnet being made of a flexible material; the stator being configured for rotating the rotor by taking along the constant magnetic field of the rotor with the time-varying magnetic field of the stator; the rotor comprising a field weakening mechanical arrangement configured for weakening a flux of the permanent magnet motor; the field weakening mechanical arrangement supporting the permanent magnet and comprising a recess configured for allowing the permanent magnet to be deformed by a centrifugal force provided by the rotation of the rotor.