A Study on Reduction of Cogging Torque and Magnet Usage through Intersect Magnet Consequent Pole Structure

Abstract

Owing to the shortage of rare-earth magnetic materials, various methods are being examined to reduce the use of magnets. One of these is a consequent pole. The consequent pole model can reduce the use of magnets by 50% using only one pole of the magnet and replacing the other pole with iron. However, the consequent pole has the disadvantage of generating back EMF asymmetry and a high cogging torque. In this study, an intersect magnet consequent pole structure is proposed to overcome the disadvantages of the existing consequent pole. Two methods have been proposed to improve axial leakage magnetic flux caused by the intersect magnet consequent pole structure. Finally, we propose a method to reduce the cogging torque and minimize the use of magnets with the same performance standard. For motor design, two-dimensional and three-dimensional finite element analysis was used, and comparative analysis was performed via simulations for several models. The existing model and the final model were compared and verified.

Structural effects of asymmetric magnet shape on performance of surface permanent magnet synchronous motors

“…Yang et al 11 proposed a novel motor with the poles and slots by combining two types of motors with different poles–slots to reduce the cogging torque. Park et al 12 and Song et al 13 proposed a cycloid curved permanent magnet and an intersect magnet consequent pole structure, respectively. Although these studies proposed innovative designs, they significantly increased the complexity.…”