Matthew Magill with advisor P.T. Krein
This work examines the underlying structure of the modern induction machine, and its similarity to past arrangements created using design tables and empirical rules. To investigate limitations of the induction process, rather than a particular system arrangement, simplified planar layer induction machine models are considered within a compositestructure framework. This process allows the effects of unusual material parameter combinations
on system performance to be studied while developing underlying material design tradeoffs and parameter sensitivities.
Inversion of mapping procedures used within established layer-based electromechanical device analysis procedures provides a natural application to the preliminary stages of electric machine design. Tractable subregion material optimization, along with the removal of design constraints associated with common machine arrangements and materials, results in idealized layered structures that can satisfy a given design objective. Initial machine realization is therefore reformulated as a de-homogenization problem, where macroscopic composite structures capable of providing the desired material parameter combinations are determined.
A double-sided linear induction motor (LIM), as given in Fig. 1, was used to experimentally examine the tool’s effectiveness in determining “from-scratch” machine de-signs. Using a uniform aluminum secondary, along with two periodic slotting composite realizations, system performance was studied and characterized through force density production. The measurements provided good agreement with theory for the uniform arrangement, as can be seen in Fig. 2, while the slotted structures displayed the applicability of the idealized two-dimensional model assumptions to three-dimensional systems. Although the fabricated arrangements were unable to produce a level of composite homogeneity required within the model, the results provide verification of the effects that are possible with the utilization of composite material structures in an LIM setting.
This research is supported by the Grainger Center for Electric Machinery and Electromechanics.