Design of a double‐sided tubular permanent‐magnet linear synchronous generator for wave‐energy conversion

Abstract

Purpose

The purpose of this paper is to present a double‐sided tubular linear machine layout direct‐drive applications, with particular focus on wave‐energy conversion. The paper documents both the computational and mathematical analysis of this novel machine layout.

Design/methodology/approach

The selection and finite‐element optimisation of the permanent‐magnet array is presented. The machine is then modelled using magnetic circuit theory. By simultaneously solving the system of equations, a demonstrative design is developed and simulated so as to validate the mathematical model and compare the performance of the new layout with a traditional layout.

Findings

A surface‐mounted magnetic array, with unshaped‐poles, is most suitable for the proposed layout. The mathematical model exhibits a suitable level of accuracy for design and analysis purposes. The calculated resultant force differs from the FEA calculation by 1.85 per cent. A higher force‐density is exhibited by the proposed layout, when compared with flat layouts, with a reduction of 36.5 per cent in the spatial footprint and magnetic material of the machine.

Research limitations/implications

Although the research is focused on the application of wave‐energy conversion, the techniques are application‐independent. However, certain design decisions should be reviewed for other applications.

Practical implications

The practical implementation of such a machine poses many mechanical obstacles. These have been solved in theory, and are being implemented at the time of writing.

Originality/value

The combination of a double‐sided and a tubular layout has not previously been researched. This research fills that void and provides designers with the technical background and a mathematical model for development of such devices.

Citation

Joseph, D.M. and Cronje, W.A. (2008), "Design of a double‐sided tubular permanent‐magnet linear synchronous generator for wave‐energy conversion", COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Vol. 27 No. 1, pp. 154-169. https://doi.org/10.1108/03321640810836726