Electromagnetic-Thermal Analysis of Axial-Flux Permanent Magnet Eddy Current Couplers with Sub-loop Calculation Method

In this paper, a precise electromagnetic–thermal model of axial-flux permanent magnet (PM) eddy current couplers is proposed to calculate the eddy current loss and predict the copper plate node temperature. With subloop calculation method, the quasi 3-D electromagnetic field analytical model is established in cylindrical coordinate. Based on the electromagnetic field analytical model, magnetic field distribution, eddy current losses of PM, copper plate and copper back iron are analyzed under various loads. The eddy current loss of each loop in the copper plate is calculated, at the rated slip speed. Then, the thermal resistance network is carried out, in which the previously obtained eddy current losses are heat sources for calculating the copper plate node temperature. In the thermal study, the influence of various loads on copper plate node temperature rise is analyzed. Finally, the analytical predicted results are compared with the results of finite element method and measurement. The comparison results confirm the validity of the electromagnetic–thermal model.