C-Type Magnet Topology for PMBLDC Motor Based Ceiling Fan

This paper presents a novel C-type magnet topology - permanent magnet brushless DC (CMT-PMBLDC) motor operating at low-speed for ceiling fan application. The C-type PM rotor features additional magnets encompassing the stator stack in the axial plane. The top and bottom magnets utilize the end winding leakage flux generated in a comparatively smaller stack length motor used in a ceiling fan and generate higher torque because of efficient flux utilization. Compared with the conventional radial flux permanent magnet brushless DC (RF-PMBLDC) motor with radially magnetized PMs, this topology achieves enhanced resultant torque. Influences of axial rotor magnets' position, magnetization direction, and dimensions on the output torque and output power are investigated. A comparison between electromagnetic performances confirms the torque enhancement and improvement in the total flux linkage in this motor topology using 3D FE analysis. In this motor, a reduction in net input power compared to conventional RF-PMBLDC is achieved.