초록 ▼

A back EMF controlled, synchronous, permanent magnet motor capable of extremely high rotation speeds at high efficiency. The motor includes a permanent magnet flux source and excitation coils for producing a rotating magnetic field mounted on an iron free form to substantially eliminate core loss an

A back EMF controlled, synchronous, permanent magnet motor capable of extremely high rotation speeds at high efficiency. The motor includes a permanent magnet flux source and excitation coils for producing a rotating magnetic field mounted on an iron free form to substantially eliminate core loss and resulting rotor drag. Back EMF is determined directly from the excitation and controls the excitation to produce a torque angle of substantially 90°between the magnet and coil fluxes. Coil excitation is used at maximum efficiency and hunting is avoided. The permanent magnet provides a high flux density that also allows a low current in the motor coils and thus reduces coil copper losses to further improve efficiency.

대표청구항 ▼

A permanent magnet A.C. motor system comprising: a permanent magnet motor having a stator and rotor, one of which includes a permanent magnet and the other of which includes electrically excitable plural windings for generating a varying magnetic field relative to said windings; means for applying A

A permanent magnet A.C. motor system comprising: a permanent magnet motor having a stator and rotor, one of which includes a permanent magnet and the other of which includes electrically excitable plural windings for generating a varying magnetic field relative to said windings; means for applying A.C. excitation to said windings; means for continuously sensing the A.C. back EMF developed in said windings during the powering thereof as a function of both winding resistance and winding inductance in response to the excitation applied thereto; means for controlling the phase angle between the applied excitation and sensed back EMF to provide maximum torque.