Performance simulation of flux modulation permanent magnet machines with three topologies

Three types of double-rotor vernier permanent-magnet (VPM) machines are compared quantitatively. They have incorporated the vernier structure and two concentric rotors within one machine. According to the PM locations, the three proposed VPM machines are referred as motor I (PM in rotor), motor II (PM in stator and rotor), and motor III (PM in stator). This paper focuses on the performance comparative analysis of the three proposed VPM machines by using time-stepping finite element method (TS-FEM). The flux distribution, air-gap flux density, induced voltage, output electromagnetic torque, core losses and efficiency of the three proposed machines have been investigated.