Modeling and Analysis of a Novel Distributed Magnetic-Pole Permanent Magnet Planetary Machine

A novel distributed magnetic pole permanent magnet planetary machine (DMPPMPM) is proposed in this article, which has the advantages of high power density, high integration, reliable transmission, and simple controllability. The proposed DMPPMPM is composed of several eccentric permanent magnet (PM) rotors. Planetary gears are connected with PM rotors and meshed with a sun gear to output a larger torque. An analytical magnetic field prediction model is established by the magnetic circuit and bilinear conformal transformation to illustrate the airgap flux density, back electromotive force (EMF) and electromagnetic torque. Furthermore, the symmetric DMPPMPM is parameterized and discussed, while the harmonic components of airgap flux density, back EMF, and torque are simplified to yield some designing instructions of the machine theoretically. Besides, the symmetric and sequence conditions are found to improve the quality of back EMF and torque. Finite element analysis and prototype experiment verify the proposed structure and instructions.