A Novel Electromagnetic Analysis Method of Spoke-type Permanent Magnet Machine with Overhang Structure

The application of overhang structures provides a way to further increase the torque and power density in limited motor space. To consider the overhang effect, this paper proposes a hybrid model that combines 2-D and partial 3-D finite element analysis (FEA). The overhang effect and end effect are considered through a partial 3-D model to reduce the number of meshes and speed up the calculation. Then, the calculation accuracy of the hybrid model and the effectiveness of considering the overhang structure are verified by the 3-D FEA model. Furthermore, a prototype with an overhang length of 6 mm is manufactured to verify the calculation accuracy of the hybrid model and the potential value of the overhang structure for improving motor performance.