A new double stator permanent magnet machine having two sets of alternating current (AC) windings in separate stators is proposed in this study. The proposed machine is appropriate for low-speed direct-drive applications. 2D- and 3D-finite element analysis (FEA) is adopted in the result predictions. The considered machine elements are: coil and phase flux linkage, coil and phase induced-electromotive force (EMF), copper loss, current density and torque characteristics. The analysis shows that the studied permanent magnet (PM) machine has better electromagnetic performance than its single-stator equivalent. Moreover, the proposed machine has potential for higher reliability if the separate stators are used independently. The effect of design parameters on open-circuit flux linkage and induced-electromotive force, as well as on the average electromagnetic torque of the proposed double stator machine is also presented. It is observed that for each of the investigated design variables, there is a need to select the optimal value in order to achieve the best average torque. The investigated design parameters are: the split ratio, magnet thickness, rotor radial thickness, inner stator tooth-width, rotor inner and outer iron-width/pitch ratio, and stator yoke size.

In this work, the electromotive force (EMF) near a permanent magnet heating cylinder was determined using a practical test bench. The aim is to elaborate three-dimensional analytical calculation capable of predicting accurately the same electromagnetic quantities by calculating the induced EMF in the presence of an inductive sensor. The analytical approach is obtained from developing mathematical integrals using the Coulombian approach to permanent magnets. In this approach, rotations are considered by Euler’s transformations matrices permitting the calculation of all permanent magnets flux densities contributions at the same points in the surrounding free space. These points, part of a uniform rectangular grid of the active EMF sensor surface, are used to compute the EMF by Faraday’s law. The validation results between experimental and simulated ones confirm the robustness and the efficiency of the proposed analytical approach.