A Study on Acoustic Noise Reduction in Brushless DC Interior Permanent Magnet Motor with Concentrated Windings

A study on magnetic force is more important than other factors, because acoustic noise of motors is mainly affected by vibration of structure. Especially, harmonics of normal force are associated with resonant frequency of structure. Therefore, although cogging torque and torque fluctuation influenced by tangential force are important factors in output characteristic, the normal force is more important for the acoustic noise. This paper deals with magnetic design to reduce the harmonics of normal force by using response surface methodology (RSM), and then the relationship with acoustic noise, cogging torque, torque ripple, and the harmonics of normal force is illustrated by experiment and simulation