Strategies for global topology optimization for given strayfield distributions

This paper introduces a global approach to magnetic topology optimization for hard magnetic materials, aiming to achieve a specific stray field distribution. The proposed method utilizes a hybrid optimization algorithm that integrates the strengths of both local and global optimization techniques. The ideas, advantages and disadvantages of each approach are discussed in detail and tested and illustrated using selected model problems. The results show that global optimization approaches are necessary to achieve significantly lower minima of the objective function, since multiple local minima might occur for such problems and the outcome of local optimization methods highly depend on the chosen starting configurations.