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Investigation of equivalent stator-winding thermal resistance during insulation system ageing

Lookup NU author(s): Dr Rafal Wrobel


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© 2017 IEEE. High performance electrical machine operation is limited by the losses generated in the machine and how well the heat developed by these losses is extracted. For conductive heat transfer from the main winding body, the insulation materials provide the main heat transfer pathway. As a machine ages through its lifetime, these materials will change their properties, and therefore these heat transfer characteristics will also alter. This paper describes the methodology and measurements on a set of motorettes undergoing an insulation ageing process to identify the change in heat transfer characteristics. The motorettes are subjected to a combination of thermal, electrical, mechanical and humidity stresses, before their thermal performance is measured. It has been found that the equivalent thermal resistance of the motorettes over the nominal lifetime of the insulation increases by over 100%, with the current carrying capability of the machine reducing by over 30% across the machine's lifetime. It is therefore recommended that this is taken into account during the initial thermal design of the machine to ensure it remains fit for purpose during its complete life.

Publication metadata

Author(s): Williamson SJ, Wrobel R, Yon J, Booker JD, Mellor PH

Publication type: Conference Proceedings (inc. Abstract)

Publication status: Published

Conference Name: 11th International Symposium on Diagnostics for Electrical Machines, Power Electronics and Drives (SDEMPED 2017)

Year of Conference: 2017

Pages: 550-556

Online publication date: 09/10/2017

Acceptance date: 02/04/2016

Publisher: IEEE


DOI: 10.1109/DEMPED.2017.8062409

Library holdings: Search Newcastle University Library for this item

ISBN: 9781509004096