Reduction of the unbalanced magnetic force of a transverse flux machine by using symmetric multipair cores

Abstract

This paper investigates the characteristics of the magnetic force and the torque in the conventional rotatory two-phase transverse flux machine (TFM) by using the three-dimensional finite element method. This research shows that the unbalanced magnetic force is one of the dominant excitation forces in this machine, and it proposes a TFM with symmetric multipair cores in which each stator core of phases A and B is divided into two and the divided cores are disposed symmetrically to cancel the unbalanced magnetic force of each phase of a TFM. However, symmetric multipair cores of a TFM may reduce the winding space of coil which results in the reduction of torque and power. This research performs the optimization of teeth-slot configuration of the stator to overcome this shortcoming. It shows that the unbalance magnetic force of a TFM can be effectively eliminated without sacrificing torque or power by introducing symmetric multipair cores.