Evolutionary Topology Optimization for Electric Machines Involving Shape Smoothing Technique

In this study, a topology optimization method designed to smooth a given surface is presented to support the generation of rotor shapes with smooth material boundaries. Shapes generated using conventional on/off-based topology optimization methods usually exhibit notable zig-zag material boundaries. Thus, users must modify the resulting shapes to make them suitable for manufacturing. These manual modifications can often reduce the performance of a fabricated part. The present method can generate the shapes with smooth boundaries; it is not necessary for such shapes to modify manually. The present method is applied to a topology optimization problem of a synchronous reluctance motor model. For comparison, the conventional on/off-based method and the body-fitted mesh approach are also applied. Numerical results show that the present method can obtain the shapes with smooth material boundaries, whose performance is not inferior to those obtained by the conventional on/off-based method. Moreover, it is also shown that the optimization speed of the present method is faster than the conventional body-fitted mesh method.