Analytic approach to magnetic circuit for saturated axial-field induction machines

Performance analysis for saturated axial-field induction machines is rather complicated due to their disc-shaped geometry and the saturation effect. A three-dimensional field computation is generally too expensive to predict their performance with engineering accuracy. To obtain the axial-field distribution in the disc-shaped planar airgap, a distributed magnetic circuit model, composed of a set of concentric ring circuit elements, is presented. By using the circuit model and an analytic method, the airgap flux and the axial-force density distributions in axial-field induction machines can be easily determined. Computed results obtained by the method are in excellent agreement with the measured results. Finally, several typical airgap field and axial force density patterns generally existing in axial-field induction machines are given.<>