Soong, W.L.Cao, Z.Roshandel, E.Mahmoudi, A.Kahourzade, S.2023-10-172023-10-172023Proceedings of the 32nd Australasian Universities Power Engineering Conference (AUPEC 2022), 2023, pp.1-69798350339567https://hdl.handle.net/2440/139688This paper performs an analysis of the variation of unbalanced forces with airgap length in axial-flux machines. A simple analytical approach is used to provide insights into these key parameters and the results compared with finite-element results for both axial-flux permanent magnet (PM) and induction machines. For PM and current-driven induction machines, the two most important parameters are the ratio of the effective magnet/core magnetic path length to the nominal airgap, and the ratio of the saturation flux density to the nominal airgap flux density. For voltage-driven induction machines, the key parameter is the ratio of stator leakage inductance to the nominal magnetising inductance.en© 2022, IEEEaxial-flux machines; axial force; finite-element analysis; negative stiffness; saturation; unbalanced forceConference paper10.1109/AUPEC58309.2022.102156132023-10-17656694Soong, W.L. [0000-0003-0734-7608]