A General Analytical Model of Permanent Magnet Eddy Current Couplings

An improved practical two-dimensional model for the analytical calculation of the magnetic field distributions in permanent magnet (PM) eddy current couplings is presented to obtain the torque characteristics. By establishing the Cartesian coordinate reference system on the rotating conductor, the PM region is treated as a source of traveling wave magnetic field and then the multi-layer boundary value problem is solved. The formulation for the magnet blocks, the eddy current and saturation effects in the solid secondary back iron, and the equivalence relationships between typical PM shapes, are all reasonably taken into account. Calculation results produced by the proposed analytical model are compared with those from the nonlinear finite element method and experimental measurement.