Abstract: Dynamic stability control for electric motors is provided. The system determines, for an electric motor of the electric vehicle, a slip frequency indicating a difference between a synchronous speed of a magnetic field of the electric motor and a rotating speed of a rotor of the electric motor. The system compares the slip frequency with a threshold. The system activates, responsive to the slip frequency greater than or equal to the threshold, a slip limiter to adjust a current command to generate an adjusted current command that causes a reduction in the slip frequency. The system deactivates, responsive to an external torque command less than a subsequent current command received subsequent to transmission of the adjusted current command, the slip limiter.

Abstract: A permanent magnet synchronous motor includes a stator, a rotor rotatable relative to the stator, and a magnetic structure with a low coercive force magnet and a high coercive force magnet that are arranged magnetically in series with respect to each other to define a pole-pair of the permanent magnet synchronous motor. A magnetization level of the low coercive force magnet is changeable by a stator current pulse such that a stator magnetomotive force at a rated current is equal to or larger than a product of a magnetic field strength for fully magnetizing the low coercive force magnet and a thickness of the low coercive force magnet.

Abstract: Dynamic stability control for electric motors is provided. The system determines, for an electric motor of the electric vehicle, a slip frequency indicating a difference between a synchronous speed of a magnetic field of the electric motor and a rotating speed of a rotor of the electric motor. The system compares the slip frequency with a threshold. The system activates, responsive to the slip frequency greater than or equal to the threshold, a slip limiter to adjust a current command to generate an adjusted current command that causes a reduction in the slip frequency. The system deactivates, responsive to an external torque command less than a subsequent current command received subsequent to transmission of the adjusted current command, the slip limiter.

Abstract: A permanent magnet synchronous motor includes a stator with a stator winding, a rotor with a rotor core rotatable relative to the stator, and a magnetic structure with at least one permanent magnet mounted to the rotor core. The magnetic structure produces a magnetic flux that flows between different magnetic poles of the magnetic structure through a main magnetic flux path that passes through the stator winding of the stator via an air gap and a leakage magnetic flux path that is located within the rotor core about an end portion of the permanent magnet near the air gap. The stator, the rotor and the magnetic structure being further configured to satisfy predetermined relationships in regards to the magnetic resistance of the main magnetic flux path and the leakage magnetic flux path, the magnetomotive force of the magnets and the stator.

Abstract: A permanent magnet synchronous motor includes a stator, a rotor rotatable relative to the stator, and a magnetic structure with a low coercive force magnet and a high coercive force magnet that are arranged magnetically in series with respect to each other to define a pole-pair of the permanent magnet synchronous motor. A magnetization level of the low coercive force magnet is changeable by a stator current pulse such that a stator magnetomotive force at a rated current is equal to or larger than a product of a magnetic field strength for fully magnetizing the low coercive force magnet and a thickness of the low coercive force magnet.

Abstract: A permanent magnet synchronous motor includes a stator with a stator winding, a rotor with a rotor core rotatable relative to the stator, and a magnetic structure with at least one permanent magnet mounted to the rotor core. The magnetic structure produces a magnetic flux that flows between different magnetic poles of the magnetic structure through a main magnetic flux path that passes through the stator winding of the stator via an air gap and a leakage magnetic flux path that is located within the rotor core about an end portion of the permanent magnet near the air gap. The stator, the rotor and the magnetic structure being further configured to satisfy predetermined relationships in regards to the magnetic resistance of the main magnetic flux path and the leakage magnetic flux path, the magnetomotive force of the magnets and the stator.