Examination of Optimal Design Method of Electromagnetic Shield Using ON/OFF Method

The topology optimization, which determines the optimal topology of nonmagnetic material in which the eddy current flows, such as an electromagnetic shield, by distributing the nonmagnetic conducting materials in the design domain, is attractive for designers of magnetic devices, because an initial conceptual design can be obtained. In this paper, the ON/OFF method which was developed for the static field problem is extended to the dynamic field problem. The method makes them particularly useful in topology optimization, where the parameterization enables all feasible shapes of electromagnetic devices to be explored. We applied the ON/OFF sensitivity method to the steady state linear eddy current problem in order to determine the optimal topology of the electromagnetic shield. As a result, the optimal shape of electromagnetic shield, which we could not imagine beforehand can be obtained using the ON/OFF method.