Characteristics investigation of a new type AFPM machine according to the geometric structure of rotor using 3D FEM.

Purpose - The purpose of this paper is to present the performance characteristics analysis of a new type axial flux permanent magnet (AFPM) machine according to the geometric structure of rotor such as permanent magnet dimension, the air-gap length and so on. Design/methodology/approach - The 3D finite element method (FEM) is used to analyse electromagnetic fields with the aid of an ANSYS software package. The FEM is based on the magnetic vector potential and the governing equation can be obtained from the Maxwell equation. Using the dynamometer system, the characteristics of the AFPM machine were estimated according to load torque. Findings - The AFPM machine characteristics with static torque, cogging torque and flux density according to rotor geometric dimensions are analyzed using a 3D FEM software package. And then, the prototype of an AFPM machine and several rotors with different PM structure are manufactured and tested. Resulting from the experiment, the characteristics such as EMF waveform, speed and efficiency curves according to load torque, and efficiency curves according to PM thickness, are obtained. The measured performance results verified the overhang effects and improved the efficiency of the motor. Originality/value - The paper proposes a new type AFPM machine structure with T-shape teeth and laminated back yoke and two types of rotor with fan-shaped permanent magnets. It presents the results of characteristics of the proposed AFPM machine throughout the simulation and experiment. [ABSTRACT FROM AUTHOR]