Analytical prediction and reduction of the cogging torque in interior permanent magnet motor

This paper proposes magnetic field analysis method which can reduce the cogging torque in interior permanent magnet motor (IPMM). The magnetic field and cogging torque are analyzed by solving the Poisson equation for magnetizing distribution. The influences of various pole ratio and magnetizing distribution on the cogging torque are investigated. It is shown that the slot and pole ratio combination has a significant effect on the cogging torque and presents a optimal link shape to reduce the cogging torque. The validity of the proposed technique is confirmed with 2-D finite element (FE) analysis