Analytical prediction of the armature reaction of permanent magnet brushless DC motor with concentrated coils

In this paper, the analytical functions of the armature reaction of permanent magnet brush less DC motor with concentrated coils are proposed by using the method of image, concerning with the configuration of these machines. This approach is different from the method of equivalent distributed current sheet and more suitable for the electric machines, which have concentrated coils and deeper slots. Under different control mode, the analytical functions of the armature reaction are different, and they are investigated. Results of this investigation show that this method is validated when further analyzing the peculiarity of the motor.