Andy Yoon with adviser K. Haran

Applications for electric machines have been proliferating with the emergence of electric transportation systems, off-shore wind turbines, and harsh environment operation. Advances in electric machine technology are considered key enablers for a number of applications. Improvement in specific power of electric machines is sought, as many industries engage with applications in mobile systems in which minimizing the volume and weight of electric motors is essential.

Current work aims to validate the effectiveness of a high-frequency, high-pole design for high power density. The design was tested with numerical models using electrical equivalent circuit models and validated using finite element models (FEM). Figures 1 and 2 show the induction machine that was cut and its corresponding FEM, respectively. Results validate that the high-frequency, high-pole-count concept is inapplicable in induction machines due to significantly low magnetizing impedance, causing low power factor. However, for permanent magnet machines, the concept is shown to be beneficial. This research is supported by the Grainger Center for Electric Machinery and Electromechanics.

Yoon_fig1-machine cut

Figure 1: 1.5 hp induction machine cut for FEM formulation

yoon-fig2diagram of cross-section

Figure 2: Finite element model based on the actual machine