Permanent magnet brushless DC motors for consumer products

This paper describes the design and performance of single-phase and three-phase permanent magnet brushless DC motors for retrofitting to a state-of-the-art vacuum cleaner. The three-phase motor was designed to match the torque-speed rating of the existing universal motor while the single-phase motor was designed to match the space envelope of the three-phase motor. The performance of the motors, in terms of their torque/speed and efficiency/speed characteristics, and EMC and acoustic noise emissions, is compared with that of the original universal motor