Topology Optimization of Rotor in Synchronous Reluctance Motor Using Level Set Method and Shape Design Sensitivity

In this paper, a new design method of shape and topology optimization is proposed to design the Synchronous Reluctance Motor (SynRM), in which the shape of the salient pole rotor determines the characteristic of the reluctance torque. In the optimal design problems based on the finite element method (FEM), the classical methods for the shape optimization has a meshing problem required for the changing geometry modeling. The level set method is employed to resolve this problem. The level set method can efficiently and easily represent complex shapes and topologies. The continuum shape design sensitivity is used for the velocity field in the level set method for the shape and topology optimization. The design goal of SynRM is to design the rotor shape for a maximum torque by redistributing the ferromagnetic material over the design domain of the rotor. The objective function to be maximized is defined as the difference of the system energy with respect to the two rotation positions. The rotor design of a 4 pole SynRM was successfully tested and its numerical results demonstrated that the proposed method is feasible and effective.