Analytical Modeling of an Axial Flux Magnetic-Geared Double-Rotor Machine With Interior-Modulating Rotor

Axial-flux magnetic-geared double-rotor machines (AMGDRMs) are characterized as a potential key component of the power-splitting system in hybrid electric vehicles (HEVs), but its conventional configuration suffers from the high axial magnetic force. In this article, an interior-modulating-rotor AMGDRM (IMR-AMGDRM) is proposed to solve this problem. To reduce computation burden, an analytical model of the IMR-AMGDRM is proposed based on the subdomain method. The analytical expressions of the magnetic field distribution and electromagnetic performances, such as torque and axial force, are developed. Finally, the results of the proposed analytical model are compared with those of the 3-D finite element analysis (FEA). The influences of the geometrical parameters of the ferromagnetic pole pieces and permanent magnets (PMs) are also investigated by the analytical model and 3-D FEA. The accuracy and the cause of the calculation error of the analytical model are studied.