Accurate Prediction and Analysis of Electromagnetic Fields and Forces in Flux-Focusing Eddy Current Coupling With Double Slotted Conductor Rotors

Abstract

Permanent magnet eddy current couplings are promising devices for torque and speed transmission without any mechanical contact. In this paper, flux-focusing permanent magnet eddy current couplings with double slotted conductor rotors are proposed and investigated. Given the drawback of the accurate 3-D finite element method, the purpose of this paper lies to establish an accurate and fast analytical model to evaluate the electromagnetic field and torque of such devices with non-homogeneous boundary conditions. Thus, based on the 2-D sub-domain method, the magnetic vector potential in each sub-domain is formulated and solved by the separation of variables method. Taking into account the eddy current effects and slotting effects, the closed-form expressions of magnetic field, induced current, electromagnetic force, and torque for such devices are obtained. Finally, the 3-D finite element method is employed to validate the analytical results.