Research on high speed slotless permanent magnet synchronous motor with a novel structure

A high-speed slotless permanent magnet synchronous motor with a novel structure was proposed for problem that inductance in high-speed slotless motor is generally small. A novel slotless structure with integrated inductance which is composed of two parts that a novel slotless core and the back around winding was applied in stator and it could significantly increase leakage inductance of windings. The double layer Halbach array was applied in rotor to reduce the distortion of sinusoidal waveform of air gap flux density. Stator structure with integrated inductor was introduced and mechanism of the increase of the leakage inductance was analyzed. The analytical method of additional leakage inductance was obtained and the relation between additional leakage inductance and the measure of stator structure was analyzed. Structure and characteristics of double layer Halbach array was introduced. The characteristics of this novel motor and normal slotless motor were compared to verify advantage of increased leakage inductance. A prototype is manufactured and the effectivity of this novel motor was proved by experiment.