Novel multi-material topology optimization method for multi-segmented permanent magnet motors

Abstract

Purpose

The purpose of this paper is to develop a novel optimization method that can improve the convergence of the multi-material topology.

Design/methodology/approach

In the proposed method, the optimization procedure is divided into two steps. In the first step, a global search is performed to probabilistically determine the material distribution of multi-segmented magnets. In the second step, the design area is limited and a local search is performed to determine the detailed magnet shape.

Findings

Because the first optimization step determines the arrangement of the magnetization vectors according to the rotational position, as in a d-axis flux concentration orientation, the optimal solution can be obtained with a smaller volume of magnets than the conventional method.

Research limitations/implications

Because a few case studies are considered in this paper, additional verification is required, such as application to different types of motors, to clarify scalability.

Practical implications

The solution obtained using the proposed method has a smaller amount of magnet than the solution obtained using the conventional method and can fully satisfy the average torque constraint.

Originality/value

The proposed method differs from the conventional method in that the material distribution is determined according to the probability function in the first optimization step.