Comparison of 2D and 3D FEA of a BLDC motor

Abstract

Until recently, the brushless direct-current (BLDC) motor had been analyzed using the 2D finite element analysis FEA) because 2D FEA is much easier to use than 3D FEA and it is more than ten times faster. However, 2D FEA ignores the magnetic field fringing and end leakage, thus leading to a trial-and-error approach to experimental design. Recently, in or der to take these effects into consideration, 3D FEA has been used for designing electromagnetic devices with a 3D shape. The objective of this paper is to study one of the inherent differences between 2D and 3D FEA, and to give guidelines for wizen to use which. Specifically, the 3D cogging torque of a BLDC motor is analyzed by changing rite teeth's height while fixing the magnet's height, and investigating the relative error between 2D and 3D analysis results for different height ratios in a BLDC motor.