자속집중형 BLDC 전동기 토크리플 저감을 위한 형상설계

Abstract

This paper presents a design strategy of Concentrated-Flux-Type BLDC motor to reduce torque ripple. The torque produced in a BLDC motor with trapezoidal Back Electromotive Force(Back EMF) is constant under ideal conditions, However, in practice, torque ripple appears on the delivered output torque. Some of these ripples result from current commutation. Another source of ripples is associated with unideal Back EMF. This paper focuses on the torque ripples associated with unideal Back EMF and minimized by shaped modification of rotor core. The characteristics of Concentrated-Flux-Type BLDC motor in accordance with winding connection method, Y-connection and Δ-connection has been identified, and shape modification of rotor core was performed to improve Back EMF shapes. Shape modification is applied to the rotor shape of Concentrated-Flux-Type BLDC motor, and the torque ripple was reduced by 15% from initial one.