A New Four-Phase Current Distribution Strategy for the Novel 6-DOF Maglev Motor

In order to decouple the electromagnetic thrust and levitation force of the 6 degree-of-freedom (DOF) maglev motor developed in the laboratory, a new four-phase current distribution strategy of the 6-DOF maglev is proposed in this paper. First, the motor structure is given, in which the mover is composed of four Halbach permanent magnet arrays, and the stator coils consist of a printed circuit board (PCB). Then, the mathematical models of electromagnetic thrust and levitation force of the motor are established based on the Lorentz force law. Moreover, the four-phase current of the stator coils is deduced by coordinate transformation and minimum norm constraint, and the relationship among the electromagnetic thrust force, levitation force, ac axis current, and dc axis current are formulated. The decoupling model of electromagnetic thrust and levitation force of the motor is built. Finally, the simulation results show the effectiveness of the proposed strategy.