An Improved Analytical Method for Cylindrical Permanent Magnet Eddy Current Couplers

This paper proposes an analytical method for calculating the characteristics of cylindrical permanent magnet eddy current couplers in a cylindrical coordinate system. For the simplified cylindrical structure of the coupler, 2D/3D electromagnetic field analytical models are established to predict magnetic field distribution, current density distribution, and torque output characteristics. The results are compared with those obtained from the finite element model, showing an error of less than 5%. A comparison between the torque output characteristics calculated in the cylindrical coordinate system and the Cartesian coordinate system indicates that the analytical method in the cylindrical coordinate system is more accurate. Under typical operating conditions, the torque output characteristics of the 3D analytical model, considering temperature correction, are compared with the experimental prototype test results, also showing an error of less than 5%. Therefore, this method allows for accurate and rapid design of cylindrical permanent magnet eddy current couplers.