Analytical Prediction and Analysis of Electromagnetic-Thermal Fields in PM Eddy Current Couplings With Injected Harmonics Into Magnet Shape for Torque Improvement

Abstract

To improve the output torque in permanent magnet (PM) eddy current couplings, a new structure based on harmonics injection into the magnet optimization theory is proposed. Then, a novel analytical electromagnetic-thermal model is established that can accurately reflect the 3-D distributions of the magnetic field and the eddy current. With the proposed analytical model, the eddy current loss, temperature distribution, torque characteristics and influence of the temperature rise caused by load increases on the torque are predicted and analyzed precisely. The maximum output torque can be improved by 11.22% with injected harmonics into the magnet shape. On this basis, an optimal design of the conductor plate structure is presented, based on the electromagnetic-thermal analytical model. An additional 13.05% torque improvement can be obtained, which leads to better torque characteristics and overload capability. Verification is conducted by a 3-D finite element analysis and measurements. The analytical model solves the multiphysics coupling analysis problem of PM eddy current couplings, and provides a fast and accurate calculation method to perform electromagnetic-thermal coupling analysis. INDEX TERMS PM eddy current couplings, torque improvement, eddy current loss, electromagneticthermal model.

A Review of Recent Developments in Permanent Magnet Eddy Current Couplers Technology

“…A four-layer field model of the quasi-Halbach PMECC is shown in Figure 11. It is worth mentioning that the authors of [115] improved the torque output of the axial-flux PMECC by constructing a magnetic field with injected harmonics in the air gap through the PM shape design.…”

Electromagnetic Modeling and Analysis of Multimaterial Cookware for Domestic Induction Heating

“…In the literature, many papers deal with electromagnetic modeling in IH. Most of them are focused on industrial applications of induction heating with solenoidal coils [24], [25] or other applications based on eddy currents [26], [27], [28], [29]. Some specialized works in domestic IH that allow to obtain the R eq and L eq are [30], [31], and [32].…”

Theoretical Computational Model for Cylindrical Permanent Magnet Coupling

“…The structural strength of each component is sufficient to meet the force requirements without the need to assemble any additional components. Previous studies on cylindrical permanent magnet coupling (CPMC) mostly employed the equivalent magnetic circuit method [10], combined Faraday's and Ampere's laws [11], established nonlinear models of cylindrical permanent magnet couplings, and investigated the impact of design parameters on the coupling performance [12,13].…”