Design and analysis of a novel two phase BLDC machine avoiding demagnetization

In this paper, a two-phase radial flux BLDC machine with concentrated winding and thin magnets is proposed which is operated in only-pull (magnetization) process and avoids the push (demagnetization) process. With this topology, while using equal amount of total copper, it is possible to achieve the same output performance as that of three-phase BLDC machine at exactly the same back-EMF for both machines and provides the protection for magnets against the loss of magnetism. As a result, thin magnets with low intrinsic coercivity and maximum energy product BH_max can be designed which benefits the overall magnet volume reduction as well as machine price is also significantly reduced.