In this paper, a new field-modulated permanent magnet (FMPM) machine with an improved rotor is proposed and analyzed. The proposed FMPM machine enjoys the advantages of high PM utilization and better heat dissipation. For a fair comparison, the proposed FMPM machine is designed with the same geometrical parameters based on the existing FMPM machine. The electromagnetic performances of existing FMPM (E-FMPM) machine and proposed FMPM (P-FMPM) are compared and analyzed by using finite element method, verifying that the proposed FMPM machine with an improved rotor can obtain high torque density and high PM utilization.

To increase the airgap flux density, this paper proposes a new magnetic-field-modulated permanent magnet (FMPM) machine. The proposed FMPM machine has the compound magnets in the rotor, which is composited by the spoke PMs (SPM) and Halbach PMs (HPM). The proposed SH-FMPM machine facilitates better use of space for armature winding and PMs and combines the benefits of high torque density and high torque/loss. The formation process, operation principle, and electromagnetic performance of the SH-FMPM machine are introduced. It is demonstrated that the SH-FMPM machine has the high torque density and low torque ripple compared to the S-FMPM machine and the H-FMPM machine.