Design and Comparison of a New Type of Magnetic-Planetary-Geared Permanent Magnet Brushless Machine for High Torque Density

This paper proposes a new type of magnetic-planetary-geared permanent magnet brushless (MPGPMBL) machines for hybrid electric vehicles (HEVs), which can achieve both power split and combination flexibly, and obtain relatively high efficiency, high torque density, low noise and small size simultaneously. For further improvement of motor performance, four topologies of MPG-PMBL machines are designed based on the different combination of the numbers of magnetic planetary gears and the layers of permanent magnets (PMs). The electromagnetic performances of the four machines are analyzed and compared in detail by the 2D finite element method. The results show the MPG-PMBL with six magnetic planetary gears and two-layer PMs possesses higher torque output capacity.