The optimal lamination approach to induction machine design global optimization

Induction motor (IM) design represents a complex multivariable optimization mathematical problem with constraints. Even advanced mathematical tools do not guarantee a global optimum. Based on a nonlinear analytical field-circuit model, this paper introduces a novel practical approach structured in two stages, the optimal lamination and the longitudinal optimization. The first stage, divided into three substages, produces a unique optimal lamination cross section for a given external stator diameter and number of poles, based on the criterion of maximum airgap flux density for given airgap and magnetization MMF. With only the external diameter and current density as independent variables, in the second stage, the chosen optimization objective function is minimized (maximized) in a straightforward iterative manner. Numerous practical examples have produced a global optimum.