Magnetic-geared permanent magnet (MGPM) electrical machine is a new type of machine by incorporating magnetic gear into PM electrical machine, and it may be in operation with low-speed, high-torque and direct-driven. In this paper, three types of MGPM machines are present, and a quantitative comparison among them is performed by finite element analysis (FEA). The magnetic field distribution, stable torque and back EMF are obtained at no-load. The results show that three types of MGPM machine are suitable for different application fields respectively according to their own advantages, such as high torque and back EMF, which form an important foundation for MGPM electrical machine research.
 Tsurumoto K., Kikuchi S., A new magnetic gear using permanent magnet. IEEE Transactions on Magnetics 23(5): 3622-3624 (1987).
 Atallah K., Howe D., A novel high-performance magnetic gear. IEEE Transactions on Magnetics 37(4): 2844-2846 (2001).
 Atallah K., Calverley S.D., Howe D., Design, analysis and realization of a high-performance magnetic gear. IEE Proc. Electr. Power Appl. 151(2): 135-143 (2004).
 Jian L., Chau K.T., Gong Y. et al., Comparison of coaxial magnetic gears with different topologies. IEEE Transactions on Magnetics 45(10): 4526-4529 (2009).
 Rasmussen P.O., Andersen T.O., Jorgensen F.T., Nielsen O., Development of a high-performance magnetic gear. IEEE Transactions on Industry Applications 41(3): 764-770 (2005).
 Jian L.K.T. Chau, J.Z. Jiang, A Magnetic-Geared Outer-Rotor Permanent-Magnet brushless machine for wind power Generation. Industry Applications 45(3): 954-996 (2009).
 Jian L., Xu G., Gong Y., Electromagnetic design and analysis of a novel magnetic-gear-integrated wind power generator using time-stepping finite element method. Progress in Electromagnetics Research, pp. 351-367 (2011).
 Atallah K., Rens J., Mezani S., Howe D., A novel pseudo direct drive brushless permanent magnet machine. IEEE Transactions on Magnetics 44(11): 4349-4352 (2008).
 Chau K.T., Zhang D., Jiang J.Z., Liu C., Zhang Y., Design of a magnetic-geared outer-rotor permanent magnet brushless motor for electric vehicles. IEEE Transactions on Magnetics 43(6): 25042506 (2007).
 Wang L.L., Shen J.X., Luk P.C.K. et al., Development of a magnetic-geared permanent magnet brushless motor. IEEE Transactions on Magnetics 45(10): 4578-4581 (2009).