Dynamic analysis of Halbach coaxial magnetic gears based on magnetic equivalent circuit modelling

Abstract

Halbach permanent magnet arrays (HPMAs) are an attractive configuration that can be applied in PM electric machines such as magnetic gears. These arrays have some merits, namely near-sinusoidal distribution of flux density along air gap, low torque ripple and iron losses. This article proposes a two-dimensional magnetic equivalent circuit method to determine the magnetic field distribution of HPMA based on coaxial magnetic gears (HCMG). Furthermore, regarding the proposed model, distribution of radial and tangential components of flux densities is extracted within outer and inner rotors. Moreover, the dynamic model of HCMG is extracted and its pull-out torque and output speed are calculated using it. Finally, in order to validate the effectiveness of the proposed model, the obtained results for a sample HCMG are compared with finite element analysis method results.