Design and Analysis of Twin-Rotor Axial Flux Permanent Magnet Synchronous Motor for Electric Bicycle using 3D Finite Element Analysis

This paper studies axial flux permanent magnet synchronous motor as an in-wheel electric motor for its application in electric bicycle. Dual rotor axial flux motor is designed and analyzed with 3D finite element analysis using Ansys software. 3D finite element analysis is used instead of analytical approach and 2D finite element analysis to obtain more accurate results even though time consumption for simulation is more. For reducing simulation time, meshing strategy is applied is to refine the mesh in air gap region and relax the mesh in remaining regions for analysis. The characteristics of the motor showing good performance for gearless transmission is inferred from analysis. Ripple in the torque response shows the presence of harmonics in system which is confirmed from Fourier transform analysis of current and back emf.