Toggle Main Menu Toggle Search

Open Access padlockePrints

A comparison of alternative linear machines for use with a direct drive free piston engine

Lookup NU author(s): Dr Nick BakerORCiD



This is the authors' accepted manuscript of a conference proceedings (inc. abstract) that has been published in its final definitive form by Institution of Engineering and Technology , 2016.

For re-use rights please refer to the publisher's terms and conditions.


In this paper the design of a linear electrical machine for use with a free-piston engine will be discussed. Three conventional permanent magnet machines are compared to a flux switching and modulated pole machine. Each of the topologies is optimised to give a specific force whilst adhering to a limit on the mass of the moving component. Using simple vector analysis, it is shown that machine power factor and efficiency are improved by optimising the machines with an objective function of minimising the MMF. Transient solver results are used to validate the static solver results and provide estimates on efficiency and operating power factor. This method of optimisation is shown to give modulated pole machines with relatively high power factors, which is a known limitation of this class of machine. The modulated pole machine topology could be the best option among all five topologies as it has high efficiency and high power factor. The flux switching machine shows some potential benefits on magnet material use ratio compared with PMs, yet it is not compliant with mass constraint.

Publication metadata

Author(s): Wang J, Baker NJ

Publication type: Conference Proceedings (inc. Abstract)

Publication status: Published

Conference Name: 8th IET International Conference on Power Electronics, Machines and Drives (PEMD 2016)

Year of Conference: 2016

Online publication date: 10/11/2016

Acceptance date: 16/02/2016

Date deposited: 27/07/2016

Publisher: Institution of Engineering and Technology


DOI: 10.1049/cp.2016.0328

Library holdings: Search Newcastle University Library for this item

ISBN: 9781785611889