Axial Field Synchronous Machine with Homopolar Flux in the airgap for a Flywheel Accumulator

A new axial-field synchronous machine designed for a flywheel accumulator is presented herein. The armature and field windings fixed in the airgap are made with double-face printed circuits. A specific armature layout provides a sinedistributed m.m.f. and solves the problem of crossing the ends of the winding. A 2D semi-analytical model at the mean radius, using surfacic permeances, is then developed. Afterwards, inductances, torque and eddy current losses are calculated using this model and compared with experimental results. Keywords: flywheel accumulator; axial-field synchronous machine; double-face printed winding; surfacic permeance.