A Novel Topology Optimization of Nonlinear Magnetic Circuit Using ON/OFF Method

Abstract

The topology optimization, which determines the optimal topology by distributing the magnetic material in the design domain, is attractive for designers of magnetic devices because an initial conceptual design can be obtained. As there occurs some gray scale elements (medium value of material density) in the optimal topology obtained by density method, it is not clear whether the region of gray scale can be treated as magnetic material or not.
In this paper, a novel topology optimization technique, which judges the existence of the magnetic material in a finite element taking account of nonlinearity of magnetic property, is proposed. The sensitivity analysis is efficiently utilized. An optimal topology of actual magnetic circuit can be obtained by using this method. The effectiveness of the proposed method is illustrated by applying it to the topology optimization of a C-core actuator. The effect of nonlinearity on the obtained optimal shape is also discussed.