Performance Comparison of Two Asymmetrical Rotor Structure Applied to BLDC Motor

Abstract

In this paper performance of BLDC motor with two different asymmetrical rotor structure were compared. Cogging
torque is one of the most important draw backs of BLDC motor. Due to the effect of cogging torque some
unacceptable effects are produced such as vibration and audible noises. The main reason behind the production of
cogging torque is the lumpy distribution of air gap permeance. Under this condition magnets try to find minimum
reluctance position. The primary aim of the design is the reduction of cogging torque and improve the performance
of BLDC Motor. The Finite Element Analysis (FEA) is carried out for the asymmetrical rotor structure method
applied to a PMBLDC motor, and analysis is done using Virtual Work Method (VWM). For the complete analyse of
the asymmetrical rotor structure of PMBLDC motor has been done using CAD software package MagNet.