초고속 Radial Blower 내 BLDC 모터의 토크리플 개선을 위한 연구

Abstract

Thanks to the stability, high torque, and operating efficiency of the super small BLDC(Brushless Direct Current) motors, it is widely used in industrial machines, especially for medical blower applications. BLDC motors in medical blower applications are attached to the impeller and supplies constant flow of oxygen for the patient. Therefore, reducing the torque ripple which occurs 6 times per cycle, thereby flattening the torque is essential. One of the means to reduce the torque ripple is to skew the PM in the rotor by the angle within the slot pitch. Moreover, additional torque ripple can be reduced when the stator core and the stator coil is skewed. The thesis verifies the reduction of the torque ripple when PM rotor is skewed considering the manufacturing simplification. Furthermore, the stator coil is skewed with a plastic molding teeth and the optimal skew angle is estimated. Accordingly, the cogging torque becomes zero because the core forms a shape of a ring with no teeth. Finally, the thesis proposes a method of applying the optimal skew angle on both rotor and stator to significantly reduce the overall torque ripple.