A Performance Prediction Model for Permanent Magnet Eddy-Current Couplings Based on the Air-Gap Magnetic Field Distribution

In this article, a clear analytical model for predicting the performance of permanent magnet (PM) eddy current couplers is proposed. The interaction of the reaction magnetic fields between adjacent eddy current rings was considered for the first time. Based on a magnetic equivalent circuit (MEC) and the Ampere circuital theorem, the accurate distribution of the air gap magnetic field under different slip velocities was deduced in a 2-D model, and the analytical expression of the transmission torque was obtained. 3-D effects were also taken into account to calibrate the model. The validity of the analytical model was verified by comparison with results from the 3-D finite element method (FEM). The comparison shows that the analytical model can accurately predict the magnetic field distribution and transmission torque over a wide range of slip velocity variations. This model can greatly reduce the number of calculations required and save time, and it is suitable for the preliminary design and optimization of PM eddy current couplers.