Design, optimization and realization of high performance outer rotor brushless DC motors

Details

Supervisors

Dehez, Bruno

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil électromécanicien

Abstract

Outer rotor brushless dc (BLDC) motors are commonly used in the slotted topology for applications such as unmanned aerial vehicles (UAV) or satellite reaction wheels. These applications could benefit from the advantages of the slotless topology using the flex-PCB technology. This Master's thesis first compares the performances of BLDC motors in the inner and outer rotor configurations, within the slotless topology on the basis of developed analytical models. It is shown that the inner rotor configuration is superior in terms of motor constant and efficiency compared to the outer rotor configuration. On the contrary, in terms of nominal torque, the outer rotor configuration outperforms the inner rotor configuration because of its higher heat dissipation capabilities. Secondly, this work compares the performances of BLDC motors in the slotless and slotted topologies, within the outer rotor configuration. On the basis of an existing slotted outer rotor motor, a slotless motor is optimized using developed models. This motor is then constructed and its performances experimentally compared to the existing slotted motor. It is shown that the slotted motor provides both a higher motor constant and a higher efficiency compared to the slotless motor.