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AC power losses

10 May 2022

If you would like to attend this training, please email Lindsey Farnsworth at l.j.farnsworth@sheffield.ac.uk.

Poster for the AC Power Losses training session.

FEMM Hub training sessions

Our training sessions are open to all hub partners - if you would like to be added to our mailing list, please get in touch via email at FEMMhub@sheffield.ac.uk.

AC power losses

13 June 2022, 10am-1pm (online)Presented by Professor Geraint Jewell (University of Sheffield, FEMM Hub Director) and Dr Rafal Wrobel (Newcastle University).


Managing copper loss is often the limiting factor on electrical machine power density. In terms of a-priori loss estimation at the design stage, copper loss is usually regarded as being more straightforward than core loss. 

However, there are a number of complicating factors in the accurate prediction of copper loss in some machines, foremost amongst which is the issue of AC loss in conductors which include phenomena such as skin and proximity effects. A failure to properly account for AC conductor loss effects during machine design and the selection of the conductor format can, in some circumstances, lead to losses which are multiples of the loss predicted from more straightforward and rudimentary considerations.

With the demand for machines to operate at ever-increasing electrical frequencies, the need to account for AC conductor loss during design and manufacture is becoming increasingly important, in particular the trade-off between the desire to use larger, rectangular cross-section conductors for a high slot-fill factor and their tendency to increase AC conductor loss. 

FEMM Hub Director Professor Geraint Jewell and Dr Rafal Wrobel from Newcastle University will jointly present this session and will cover the key issues of AC conductor loss, from fundamentals of the electromagnetic mechanisms at play through to practical strategies for minimising the magnitude of the losses. The content has been structure to allow engagement from non electrical engineering attendees with the initial sections focusing on establishing a basic understanding of the electromagnetic and electrical principles which underpin AC conductor loss. 

This training session is open to all members of staff at our hub partners.

To sign up for this session, email l.j.farnsworth@sheffield.ac.uk.