Fast Calculation of Magnetic Field Distribution in Magnetic Gear for High Torque Application

For applications demanding high torque and high reliability transmission, coaxial magnetic gear (CMG) may be a promising substitute of the mechanical gearbox. However, with the increasing of unit capacity, CMG tends to have a big size with large pole number, which would lead to heavy computation burden if finite element method (FEM) is employed. Analytical methods are therefore expected. To date, only the exact subdomain model is capable of precisely predicting the magnetic field behaviors in an analytical manner through solving a matrix equation. However, as pole number of the CMG increases, the number of subdomain increases correspondingly, resulting in the growth of dimension of the matrix equation and thus the growth of computation cost. Therefore, the motivation of this paper is to develop a time-efficient solution for the subdomain model of the scaled-up CMG, which could efficiently reduce the size of the matrix to be inverted and computational burden. Finally, FEM is employed to confirm the validity of the developed analytical calculation.