Analytical modeling of linear oscillating motor with a mixed method considering saturation effect

• A mixed analytical model for linear motor considering saturation is proposed.
• Open-circuit and armature reaction field is analyzed by magnetic potential vector method.
• 3D-EMC method is used for saturation compensation by introducing corrected factor.
• Parallel magnetization is compared with ideal radial magnetization and shows the possibilities of substitution.

Linear oscillating motor receives much attention recently due to direct and efficient linear motion output. In order to achieve high thrust and eliminate eddy current effect, circumferential silicon steel stack is usually utilized in stator as a universal topology design. However, circumferential arrangement of silicon steel introduces 3D magnetic circuit, which complicates the design process and cannot be solved using conventional modeling method. In addition, it leads to severe magnetic saturation effect and must be taken into accounts in the analytical model for accurate results. In this paper, a novel mixed analytical modeling method for linear oscillating motor with silicon steel stator is proposed. Magnetic potential vector (MPV) and 3D equivalent magnetic circuit (3D-EMC) methods are combined together in this mixed model. Magnetic potential vector method sets up the coarse flux density distribution, while 3D equivalent magnetic circuit method is used for refinement considering saturation. Moreover, the performance between radial and parallel magnetized structure is compared based on this model. For validation, FEM and experimental results are compared with the proposed model and proves its effectiveness and accuracy, which can be used in further motor structure optimization. It may also act as a universal guidance to other PM motor design.