Dynamic modeling of coaxial magnetic gears based on magnetic equivalent circuit using nodal analysis method

Magnetic gears in comparison with mechanical type have a lot of features like high reliability, low vibration and acoustic noise, overload protection, input and output shafts insulation, and less repair and maintenance requirements. Having a semi-analytic model based on the magnetic equivalent circuit (MEC) compared with the finite element method can reduce the time needed in the preliminary stages of the design process. In this paper, a two-dimensional modeling of a coaxial magnetic gearbox based on a MEC is presented using the nodal analysis method. Using the proposed model, the magnetic potentials of the circuit nodes are first obtained and the magnetic field distribution, fluxes, inner and outer rotor torque are determined in different parts of the gear. In this modeling, a dynamical model of the gear is presented. Using this model, the torque-angle characteristic, torque ripple and pullout torque of the gear are extracted. In addition, the effect of the load torque variation on the MG dynamics is evaluated. Finally, in order to validate the proposed model, the model results are compared with the finite element analysis.