Topology optimization of electromagnetic devices using oriented iron microstructures

Abstract

Purpose

The purpose of this paper is to propose a mechanism avoiding the topology optimization methods, and particularly those using gradient‐based algorithms, to be trapped in local minimizers when applied to the design of electromagnetic devices made of iron and permanent magnet.

Design/methodology/approach

Topology optimization methods aim at finding the optimal distribution of some materials in cells subdividing a design space, regarding a specific objective function. This paper suggests to consider that each cell contains an oriented microstructure of iron whose direction and shape are optimized by the method.

Findings

Coupled with convexity and sensitivity mappings quite common in the field of topology optimization, the use of the microstructure allows the optimization algorithm to converge systematically toward the same design. This achievement is illustrated on a practical case, i.e. the optimization of the rotor of a permanent magnet synchronous motor regarding its mean torque and under mass constraint. Also, this paper shows that intermediate iron materials can either be penalized or interpreted, thanks to the realistic physical relations derived from the iron microstructures.

Originality/value

This paper proposes a mechanism based on an iron microstructure for avoiding the topology optimization methods and the trap of local minimizers when applied to the design of electromagnetic devices made of iron and permanent magnet.

Citation

Labbé, T., Matagne, E. and Dehez, B. (2012), "Topology optimization of electromagnetic devices using oriented iron microstructures", COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Vol. 31 No. 5, pp. 1408-1416. https://doi.org/10.1108/03321641211248084