Permanent magnet assisted synchronous reluctance motor for increasing minimum electromagnetic torque

摘要

A permanent magnet motor, comprising a stator (1) and a rotor (4); the rotor comprises a rotor iron core (5) and permanent magnets (7a, 7b); in the radial direction of the rotor, each magnetic pole of the rotor iron core is provided with multiple layers of arc-shaped permanent magnet grooves (6a, 6b); a q-axis magnetic flux path is formed between two neighboring magnetic poles; the permanent magnets are disposed in the permanent magnet grooves; two neighboring magnetic poles of the rotor are respectively a first magnetic pole and a second magnetic pole having opposite polarities; an outer endpoint of a permanent magnet in the first magnetic pole is a first outer endpoint, said outer endpoint is farther from the q-axis; an outer endpoint of the permanent magnet in the second magnetic pole is a second outer endpoint, said outer endpoint is farther from the q-axis; an included angle A of the first outer endpoint and the second outer endpoint with respect to the center of the rotor is less than an electrical angle of 80 degrees, the number of stator slots being N, the number of pairs of rotor poles being P, the number of phases of windings being m, and the number of stator slots per pole per phase (N/2P/m) being an integer. As compared with motors having existing structures, the permanent magnet motor dramatically reduces the torque ripple thereof.