Stray load losses in induction motors: a challenge to academia

In the February 1997 issue of Power Engineering Journal, Prof. Stephen Williamson published a short article entitled 'Stray losses-a residue of ignorance'. In a paper by the author published at the Lisbon Conference on 'Energy efficiency improvements in electric motors and drives' in October 1996, it was concluded that the subject of stray load losses had suffered from academic neglect. This article steers a path between the accusations of neglect and ignorance and presents the challenging case for revisiting the problems and issues with the benefit of new technologies. The author discusses the sources and effects of stray load losses, standards and levels of stray load losses, and the need for energy conservation. The author concludes that the following are urgently needed: to be able to accurately calculate stray load losses; to be able to define and control the material and process variables associated with the generation of stray load losses; to be able to accurately measure stray load losses; and new theories, technologies and work programmes to achieve the above.