The Influence of the pole asymmetry on the BLDC motors

In this paper, three-phase interior type permanent magnet motor is modeled. The modeling is achieved by using Finite Elements Method (FEM) for healthy and asymmetric pole conditions. In this model, the motor´s characteristics such as cogging torque, back electromotive force (back EMF), power, torque and magnetic force are obtained and the results are compared with the experimental results for the healthy case. Also these parameters are obtained at asymmetric pole conditions that include different magnet type and size caused by manufacturing or partial demagnetization. The back EMF harmonics and the cogging torque are analyzed for different magnet length and height.