Design and Analysis of a High-Speed Permanent Magnet BLAC Motor for Hand Dryer Application

In hand dryer application, high efficiency is preferred to decrease energy consumption, and low torque ripple is crucial to reduce the motor's vibration and noise. This paper presents three designs for a 1 kW, 83 krpm permanent magnet brushless AC machine for hand dryer application, namely initial design, less-PM design, and more-PM design. The initial design is used as a benchmark, and the two other designs are proposed to enhance the efficiency and minimize the torque ripple by increasing the armature inductance. Using two-dimensional finite-element analysis (FEA), the electromagnetic performance including back EMF, cogging torque, average torque, torque ripple, losses, and efficiency is investigated and compared under no load and load conditions. In terms of efficiency, all three machine designs achieve an efficiency above 90%, meeting the target design requirements. On top of that, the less-PM design effectively reduces the torque ripple by 25% and rotor eddy current loss by 34%, while the more-PM design achieves a significant reduction in rotor eddy current loss by 45% and the torque ripple by 10%, making both designs optimal for improved performance and efficiency.